Identification Guide to Marine Invertebrates of Texas

by Brenda Bowling Texas Parks and Wildlife Department April 12, 2019 Version 4 Page 1 Marine Crabs of Texas

Mole crab Yellow box crab Giant hermit Surf hermit Lepidopa benedicti Calappa sulcata Petrochirus diogenes Isocheles wurdemanni Family Albuneidae Family Calappidae Family Diogenidae Family Diogenidae

Blue-spot hermit Thinstripe hermit Blue land crab Flecked box crab Paguristes hummi Clibanarius vittatus Cardisoma guanhumi Hepatus pudibundus Family Diogenidae Family Diogenidae Family Gecarcinidae Family Hepatidae

Calico box crab Puerto Rican sand crab False arrow crab Pink purse crab Hepatus epheliticus Emerita portoricensis Metoporhaphis calcarata Persephona crinita Family Hepatidae Family Hippidae Family Inachidae Family Leucosiidae

Mottled purse crab Stone crab Red-jointed fiddler crab Atlantic ghost crab Persephona mediterranea Menippe adina Uca minax Ocypode quadrata Family Leucosiidae Family Menippidae Family Ocypodidae Family Ocypodidae

Mudflat fiddler crab Spined fiddler crab Longwrist hermit Flatclaw hermit Uca rapax Uca spinicarpa Pagurus longicarpus Pagurus pollicaris Family Ocypodidae Family Ocypodidae Family Paguridae Family Paguridae

Dimpled hermit Brown banded hermit Flatback mud crab Estuarine mud crab Pagurus impressus Pagurus annulipes Eurypanopeus depressus Rithropanopeus harrisii Family Paguridae Family Paguridae Family Panopeidae Family Panopeidae

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Smooth mud crab Gulf grassflat crab Oystershell mud crab Saltmarsh mud crab Hexapanopeus angustifrons Dyspanopeus texanus Panopeus simpsoni Panopeus obesus Family Panopeidae Family Panopeidae Family Panopeidae Family Panopeidae

Tube pea crab Longnose spider crab Portly spider crab Spotted porcelain crab Pinnixa chaetopterana Libinia dubia Libinia emarginata Porcellana sayana Family Pinnotheridae Family Pisidae Family Pisidae Family Porcellanidae

Green porcelain crab Eastern tube crab Sargassum swimming crab Iridescent swimming crab Petrolisthes armatus Polyonyx gibbesi Portunus sayi Portunus gibbesii Family Porcellanidae Family Porcellanidae Family Portunidae Family Portunidae

Florida lady crab Blue crab Speckled swimming crab Lesser blue crab Ovalipes floridanus Callinectes sapidus Arenaeus cribrarius Callinectes similis Family Portunidae Family Portunidae Family Portunidae Family Portunidae

Blotched swimming crab Squareback marsh crab Gulf squareback crab Portunus spinimanus Armases cinereum Speocarcinus lobatus Family Portunidae Family Sesarmidae Family Xanthidae

Page 3 Page 4 Page 5 Arrow Crabs - Inachidae

Crabs in the Inachidae family belong to a group of crabs known as arrow (or spider) crabs. Their bodies are either round or triangular shaped, usually narrowing at the anterior end. They all have an extend rostrum anteriorly that may be short or extremely long and narrow, and either simple or forked. Their legs are narrow and long, resembling that of a spider. Their heads lack orbits for their eyes to lie into.

Page 6 False arrow crab Metoporhaphis calcarata Family Inachidae - Spider crabs

Carapace triangular, longer than wide, narrower in the front, knobby, knobs surmounted by a tubercle; long thin simple rostrum (extended snout), as long or Distinguishing longer than carapace, pointed; color brown to gray; eyes protrude sideways, no Characteristics orbits; claw appendages shorter than other legs; legs long and slender; long spine extending dorsally at 1st joint in legs with smaller spines ventrally. The yellowline arrow crab has a smooth carapace with yellow lines, no Similar Species prominent spines at joints on legs. Gulf, possibly high salinity bays; found around hydroids and other fouling Habitat organisms on hard substrates Maximum Size 2.4 cm (1 in) carapace length, 1 cm (<1/2 in) carapace width

Page 7 Box Crabs - Calappidae and Hepatidae

Some crabs of the Calappidae family have the ability to hide their legs and claws close to their shell, appearing box-like and inert, thus the name "box crabs". They are also known as "shame-faced" crabs for the way they hold their broad flat claws over the anterior region of their shell, as if hiding their face. Their claws are highly ornamental and are fringed with tiny hairs. It is believed that the hairs filter sand and other particles from water that is siphon into the body and across the gills to extract oxygen. This is useful when the crab is buried in the sediment. One claw has a specialized enlarged tooth that is used to "peel" open gastropod shells, similar to using a can opener.

The family Calappidae has recently undergone revision and its genera were split into four different families. Of those families, only Calappidae and Hepatidae are present in the Gulf of Mexico.

Page 8 Calico box crab Hepatus epheliticus Family Hepatidae - Box crabs

Carapace oval, wider than long, narrowing at the posterior end; color light tan background with large reddish brown spots on carapace and legs, pinkish to Distinguishing white underneath; lateral margins with small blunt spines; claws broad, flat with Characteristics 3-4 teeth on crest; one claw with enlarged tooth on movable finger fitting into cup-like depression on immovable finger; claws mostly white, inside is smooth, outside is rugged; claws are held close to anterior carapace. Very similar to the flecked box crab. The pattern on the carapace easily Similar Species distinguishes the two. Calico box crab has large spots. Flecked box crab has transverse lines or very small spots. Habitat Gulf, prefers sand or muddy bottoms Maximum Size 8 cm (3 1/5 in) carapace width

Page 9 Flecked box crab Hepatus pudibundus Family Hepatidae - Box crabs

Carapace oval, wider than long, narrowing at the posterior end; color brownish with darker transverse broken rows that bend posteriorly at the lateral ends, alternately may be covered with small darker spots or a combination of Distinguishing transverse lines and spots; front at edge of carapace between orbits thick and Characteristics slightly bi-lobed; lateral margins with small blunt spines; claws broad, flat with 3-4 teeth on crest of claw; one claw with enlarged tooth on movable finger fitting into cup-like depression on immovable finger; claws mostly white, inside is smooth, outside is rugged; claws are held close to anterior carapace. Very similar to the calico box crab. The pattern on the carapace easily Similar Species distinguishes the two. Calico box crab has large spots. Flecked box crab has transverse lines or very small spots. Habitat Gulf Maximum Size 7.5 cm (3 in) carapace width

Page 10 Yellow box crab Calappa sulcata Family Calappidae - Box crabs

Carapace oval, wider than long, curved anteriorly, nearly flat posteriorly; color varies from pink to dark brown; lateral margins with spines, posterior one being Distinguishing the largest; claws broad, flat, distinct hump on anterior end before movable Characteristics finger; several teeth on crest of claw; outer surface with 2 rows of low tubercles (bumps), one claw with enlarged tooth on movable finger fitting into cup-like depression on immovable finger; claws are held close to anterior carapace. Looks similar to the flame box crab, but the flame box crab has irregular Similar Species markings or lines on its carapace. Habitat Gulf Maximum Size 14.5 cm (5 3/4) carapace width Other Common Names shamefaced crab

Page 11 Fiddler Crabs and Ghost Crabs - Ocypodidae

Ocypodidae is a family of mostly semi-terrestrial crabs that live in burrows in soft sand or mud within the intertidal stretches of bays and beaches. When the tide goes out, the crabs will come out of their burrows in search for food. While most crabs in this family live intertidally, some live a more aquatic life while others live supratidally in a more terrestrial setting. All must venture back to the water for breeding and normal larval development.

Fiddler crabs are most easily distinguished by the oversized claw of the male. The male uses the enlarged claw for combat and communication. The smaller claw is used for feeding. The motion of the small claw being raised and lowered from the mouth gives the appearance of strumming the larger claw, thus the name fiddler crabs. Once the fiddler is through sifting through a claw full of sand for food, the sand is deposited in the form of a little ball. These balls are typically found outside the burrows of fiddler crabs. When male fiddler waves its larger claw in the air and taps it on the ground, he is displaying a courtship ritual in an effort attract a female.

Ghost crabs have an enlarged claw also, but not quite the extent of the male fiddler. They are called ghost crabs because they are blend into their background and can easily disappear by running in zigzag lines with speeds up to 10 mph. Their stocked black eyes stand erect giving the ghost crabs 360° vision. Their vision is so acute they can spot and grab insects in mid-air. However, they cannot see directly above themselves which make them easy prey for birds. Ghost crabs are nocturnal, being more active at night than during the day. They are mostly found on beaches. Their burrow holes are about the size of a golf ball. Adult males rearrange the sand that is excavated from its burrow into a pile beside the hole. Adult females and juveniles just scatter the sand outside the holes. These tell-tale signs plus crab tracks around the holes indicate the home of a ghost crab.

Page 12 Atlantic ghost crab Ocypode quadrata Family Ocypodidae - Fiddler and ghost crabs

Carapace rectangle in shape; slightly longer than wide; color grayish white to yellow, may have intricate designs on back to camouflage themselves with Distinguishing sandy substrate; claws white, one claw larger than the other, covered with Characteristics nodules (bumps), margins of claws serrated; eyes on stalk that stand straight up when alive, cornea covers at least 1/2 eye stalk; legs are covered with setae (hairs). This is the only ghost crab in the Gulf of Mexico. If you see a crab scurrying Similar Species around on the beach and then disappearing into holes in the sand, it is the Atlantic ghost crab. Habitat Gulf beaches, live in burrows in the sand above the tidal zone Maximum Size 6.4 cm (2 1/2 in) carapace width

Mudflat fiddler crab Page 13 Uca rapax Family Ocypodidae - Fiddler and ghost crabs

Carapace oval, narrower posteriorly; anterior lateral margins slightly curved; color greenish brown or greenish blue on carapace, claws white with yellow or orange tinge, mottled brown spots on back of palm; females with very small claws of equal size; males with 1 oversized claw with short tubercle ridge on palm, ridge relatively high, tubercles stop at top of ridge, do not continue to other side of palm; no enlarge tooth or spine on inner surface of carpus Distinguishing (segment next to claw) on enlarged claw in males; palm of male major claw Characteristics mostly smooth, sometimes with a few small flat tubercles; crest on end of immovable finger of major claw with 3-4 tubercles, the immovable finger is slightly curved inward; walking legs with hairs on dorsal and ventral margins; pile of short bristly hairs (seen with magnification) on the dorsal margin of its 1st 3 walking legs; area between orbits narrow, less than 1/3 of the frontal width of the carapace. Most resembles the Atlantic marsh fiddler, U. pugnax, but the Atlantic marsh fiddler differs in these ways: the immovable finger on the male major claw is straight or with a slight downward curve; the fingers are longer and narrower than the mudflat fiddler; the merus (4th segment from distal end) of the 2nd walking leg is more slender, its dorsal edge straight; ridge on major palm is Similar Species relatively low, center of palm clearly tubercled, tubercles on palm ridge continue around around carpal cavity to upper side of palm, The red-jointed fidder has red color in the joints of major claw and has no pile of hairs on the dorsal margin of its walking legs; The spined fiddler has straight anterio-lateral margins in its carapace. Other fiddlers may have no tubercled ridge on its inner palm of the major claw. Habitat Bay, muddy bottoms, above the intertidal zone Maximum Size 2.1 cm (1 in)

Page 14 Red-jointed fiddler crab Uca minax Family Ocypodidae - Fiddler and ghost crabs

Carapace rectangular, wider than long, slight wider anteriorly, lateral edge of carapace curved anteriorly (not straight); when viewed from the side, the carapace is more convex anteriorly than posteriorly; females with very small Distinguishing claws; males with 1 oversized claw with oblique tubercle ridge from inner Characteristics margin of palm to outer edge of claw; oversized claw with red spots on articulations; merus (4th segment from tip) of 2nd and 3rd walking legs with sparse (as opposed to dense patches) rows of stiff hairs on inner surfaces. Males are easier to distinguish from other fiddler crabs because of the red Similar Species coloration in its articulation area. Habitat Bay, muddy bottoms, above the intertidal zone Maximum Size 2.5 cm (1 in) carapace width

Page 15 Spined fiddler crab Uca spinicarpa Family Ocypodidae - Fiddler and ghost crabs

Carapace oval, narrower posteriorly; anterior 1/3rd of lateral margins straight, with an angular bend posteriorly; color brown on carapace, whitish on ends of Distinguishing claws; females with very small claws; males with 1 oversized claw with oblique Characteristics tubercle ridge from inner margin of palm to outer edge of claw; enlarge tooth or spine on inner surface of carpus (segment next to claw) on enlarged claw in males. Spined fiddlers can be distinguished by the straight edges of the anterolateral Similar Species margins of its carapace and by the small tooth or spine on the interior margin of the carpus in the oversized male claw. Habitat Bay, muddy bottoms, above the intertidal zone Maximum Size unknown

Page 16 Hermit Crabs - Paguridae and Diogenidae

Hermit crabs are not considered to be "true" crabs. They lack an external shell on their soft abdomen which leaves them vulnerable to predators. To protect themselves they live in abandoned gastropod (snail) shells. Their last 2 pair of legs are small and modified and along with its uropods (appendages at the end of the abdomen) are used to clamp onto the internal whorls of the shell. Trying to remove a hermit crab from his home is difficult without tearing the crab apart. The whole body can be retracted into the shell, when needed. Eventually the hermit crab will outgrow his shell and will search for a new one. Each hermit crab has a pair of claws and 2 pair of walking legs (5 pair of leg appendages in all).

Hermit crabs in the families Paguridae and Diogenidae are all aquatic marine crabs. The terrestrial hermit crabs found in many pet stores belong to another family and can be found in Florida and the Caribbean areas. Paguridae are called the right-handed hermit crabs because the right claw is usually larger than the left claw. Diogenidae are left-handed hermits because the left claw is usually the largest. Unfortunately, these are generalizations and don't always hold true, so it's not really a good way to distinguish families. Most hermit crabs off Texas can be identified by their size, color and shape of their claws.

Page 17 Blue-spot hermit Paguristes hummi Family Diogenidae - Left-handed hermit crabs

Lives in gastropod shells; abdomen soft, twisted, hidden inside shell; carapace and claw color off-white; eye stalks bluish to gray, blue spot with black border Distinguishing on upper part of claw appendages; claws 2X longer than wide, left and right Characteristics equal in size, with small setae (hairs), with some bumps (not smooth); a small hermit crab. A small hermit; distinguished by the blue spot with black outline on upper area Similar Species of claw appendages. Habitat Shallow Gulf Maximum Size unknown, very small

Page 18 Brown banded hermit Pagurus annulipes Family Paguridae - Right-handed hermit crabs

Lives in gastropod shells; abdomen soft, twisted, hidden inside shell; carapace Distinguishing and claw color light with brown bands on claw appendages and walking legs; Characteristics right claw larger than left; right claw long, cylindrical, about 2X longer than wide, granulated, with setae (hairs); a tiny hermit crab. The brown banding on legs and claws distinguish this hermit; this is a tiny Similar Species hermit, hard to see characteristics without a magnifier; usually inhabits nassa shells. Habitat Gulf Maximum Size unknown, very small, probably <1/2 in

Page 19 Dimpled hermit Pagurus impressus Family Paguridae - Right-handed hermit crabs

Lives in gastropod shells; abdomen soft, twisted, hidden inside shell; brown with lighter transverse stripes on upper claw appendages; legs with alternating bands of light color; eye stalks brown above, blue below; right claw larger than Distinguishing left; right claw oval in shape, slightly longer than wide, outer edge of movable Characteristics finger rounded; left smaller claw not as wide, narrowing at the tips; outer margins of claws with bumps or small blunt spines; claws granular; a medium sized hermit crab. The broad brown claws, alternating bands of light on legs and upper arms of Similar Species claw appendages distinguish this species. Habitat Gulf and bay Maximum Size unknown

Page 20 Flatclaw hermit Pagurus pollicaris Family Paguridae - Right-handed hermit crabs

Lives in gastropod shells; abdomen soft, twisted, hidden inside shell; carapace and claw color off-white; dusky color on central upper surface of claw and Distinguishing between fingers of claws; claws broad, flat, outer margins with small bumps or Characteristics blunt spines; right claw much larger than left claw; prominent angle on outer edge of movable finger; claws somewhat granular; a medium sized hermit crab. Similar Species The flat claws with distinct angle on movable finger distinguish this hermit. Habitat Gulf and bay Maximum Size 5 cm (2 in) body length

Page 21 Giant hermit Petrochirus diogenes Family Diogenidae - Left-handed hermit crabs

Lives in gastropod shells; abdomen soft, twisted, hidden inside shell, carapace and claw color red; claws unequal (right claw is larger), heavily knobbed, knobs whitish or lighter color than rest of claw; tubercles (knobs) on crushing surface Distinguishing of major claw; minor claw slightly spooned; back behind eyes is flat, tri-lobed in Characteristics fromt; red hairs on body, especially long on last 2 segments of walking legs; antennae are white and red striped; tufts of hair above the corneas of the eyestalks. The giant hermit crab can be distinguished by its size (largest hermit crab in Similar Species Texas) and its heavily tubercled, red claws. Habitat Gulf and high salinity bays, mud, shell and sand bottoms Maximum Size unknown, very large, estimated around 48 cm (19 in) including claws

Page 22 Longwrist hermit Pagurus longicarpus Family Paguridae - Right-handed hermit crabs

Lives in gastropod shells; abdomen soft, twisted, hidden inside shell; carapace and claw color off-white, claws with gray or brown median stripe; right claw Distinguishing elongate, cylindrical, about 4X longer than wide; left claw short; claws not Characteristics heavily tubercled (bumpy) with no setae (hairs), left claw with a few hairs; a small hermit crab. Its elongate right claw with gray or brown median stripe distinguishes this Similar Species hermit. Habitat Gulf, lower bays Maximum Size 2.5 cm (1 in) body length

Page 23 Surf hermit Isocheles wurdemanni Family Diogenidae - Left-handed hermit crabs

Lives in gastropod shells; abdomen soft, twisted, hidden inside shell; carapace Distinguishing and claw color off-white; claws slightly longer than wide, fingers short, curved Characteristics at tips; heavily tubercled (bumpy); lots of setae (hairs); left claw slightly larger than right claw; a small hermit crab. Distinguished by its short stubby claws, heavily tubercled and hairy, curved at Similar Species the tips, left claw slightly larger than right. Habitat Gulf Maximum Size unknown, very small

Page 24 Thinstripe hermit Clibanarius vittatus Family Diogenidae - Left-handed hermit crabs

Lives in gastropod shells; abdomen soft, twisted, hidden inside shell; carapace Distinguishing and claw color orange brown to brown, light stripes on walking legs; distinct Characteristics groove behind anterior margin of carapace; claws equal, a few setae (hairs), 2X longer than wide, with light bumps; medium sized hermit crab. Similar Species The white and brown stripes on the walking legs distinguish this hermit. Habitat Gulf and bay Maximum Size unknown, larger than many hermit crabs

Page 25 Land Crabs - Gecarcinidae

Land crabs are "true crabs" that have adapted to a terrestrial lifestyle. The undersides of their gill plates have a network of blood vessels that extract oxygen from the air. They still have the traditional gills of crabs and have to return to the seas for breeding and normal larval development. Their breeding is highly synchronized with the lunar and seasonal cycles, and mass movements of crabs have been observed. They are mid to large size crabs and many have deep brilliant colors. On land, they have been known to eat and destroy crops.

Page 26 Blue land crab Cardisoma guanhumi Family Gecarcinidae - Land crabs

Carapace oval narrowing posteriorly, widest anteriorly, globular, smooth with fine ridge on sides and anteriorly; color dark brown, purple or orange in Distinguishing juveniles, bluish gray in adult males, gray or white in adult females; one claw Characteristics larger than the other; last legs regular, not flattened; medium to large crab; lives in burrows on land. The only other land crab in Texas, the blackback land crab, has a dark brown Similar Species spot covering most of the dorsal carapace and the rest of the crab is reddish, orange, or white. Habitat Mostly terrestrial, burrows close to water sources (bay or groundwater) Maximum Size 15 cm (6 in) carapace width

Page 27 Marsh crabs - Sesarmidae

Sesarmidae, the marsh crabs, similar to the grapsid crabs, have pointed legs with hooks or spines that allow them to easily climb trees and such or scramble over slippery surfaces. Their carapace is usually squarish, with straight or slightly curved lateral sides. They live above the high tide line on rocks and jetties, in marshes and among mangroves. Some crabs that live out of water are termed "semiterrestrial" because the females need saltwater to release their eggs, and the eggs go through a typical marine plankton development. However, many of the marsh crabs are entirely terrestrial and do not need the sea to survive. These crabs breathe by holding water in their gill chambers and recirculating the water over the gills for oxygen exchange.

Page 28 Squareback marsh crab Armases cinereum Family Sesarmidae - Marsh crabs

Carapace squarish; lateral sides straight with no lateral teeth; color brown with some darker markings; claws with white fingers, brown on upper surface of Distinguishing movable finger, tips of both fingers dark; surface of outer mouth part with Characteristics oblique hairy ridge; no tooth behind the outer eye tooth; fourth walking leg with black spines on upper and lower surfaces; male claws grow larger than female claws; small tubercles (bumps) on upper surface of movable finger; The mangrove marsh crab (Sesarma curacaoense) and the purple marsh crab (S. reticulatum) have a tooth behind the outer orbital tooth. The humic marsh Similar Species crab (A. ricordi) is orange to reddish brown and lacks the bumps on the upper movable finger. Habitat Bay, intertidal or above tidal zone, rocks and marshes, sandy bottoms Maximum Size 2 1/2 cm (1 in) Previous Scientific Sesarma cinereum Names Squareback marsh crabs live in a marine environment but do not require Comments seawater to survive, making them true terrestrial crabs. They still need a source of water, though, for oxygen exchange across its gills.

Page 29 Mud Crabs - Panopeidae, Menippidae and Xanthidae

Panopeidae and Menippidae were, until recently, in the family Xanthidae, which contained more genera of crabs than any other crab family. Recent revisions in taxonomy split the Xanthidae family into seven separate families. The crabs in these families are oval to hexagonal in shape, with a broad anterior, never with a protruding rostrum. Their last pair of legs are normal, not flattened into a flap to swim with. Some members of this family, none in our area, contain toxins in their exoskeleton. Most of these crabs are associated with colonial invertebrate colonies, such as corals, sponges, tunicates and bryozoans. The crabs in Texas' waters are mostly associated with oyster reefs, feeding off encrusting organisms and other small animals that take shelter between oyster shells. Only one of these crabs grows large enough to be a serious predator of the oysters, the stone crab with its huge claws capable of crushing the oyster shell into bits. Though these crabs are marine, the estuarine mud crab (Rhithropanopeus harrisii) has recently invaded several of Texas' freshwater reservoirs.

Page 30 Estuarine mud crab Rithropanopeus harrisii Family Panopeidae - Mud crabs

Carapace almost squarish, about as long as wide, anterior rounded, wider than posterior, front with slight notch; mid to posterior lateral sides straight, posterior margin slightly rounded; front margin has a groove between the eye, looks like a double ridge when view anteriorly; color olive green to brown (not solid) with Distinguishing variously scattered dark dots; last legs regular, not flattened; 5 spines on Characteristics anterior lateral edges of carapace, anterior 2 fused into low lobe, 3rd and 4th blunt, 5th small; claws unequal, major claw with few low teeth but no enlarged tooth; top of claws brownish with scattered dots, fingers and palms white; no red spot under outer mouth parts. Distinguished from other local mud crabs by no enlarged tooth on major claw, immovable finger on minor claw not spooned out on inner surface, no red spot Similar Species under outer mouth part; has a groove on front edge of carapace between eyes (probably need a magnifier to see), and claws are white. Habitat Bay, oyster reefs Maximum Size 2 cm (3/4 in) carapace width

Page 31 Flatback mud crab Eurypanopeus depressus Family Panopeidae - Mud crabs

Carapace oval anteriorly, posterior lateral sides straight, flat posteriorly, body wider than long; color grayish-olive to brownish with a little pale mottling; last legs regular, not flattened; 5 spines on anterior lateral edges of carapace, Distinguishing anterior 2 form a broad lobe slightly concave between; claws unequal in size; Characteristics major claw with few low teeth, no enlarged tooth; minor claw with immovable finger scooped out into a spoon shape; both claws fingers brown, white at tip; dark red spot under outer mouth parts (3rd maxillipeds) in both sexes. Distinguished from other local mud crabs by no enlarged tooth on major claw, Similar Species immovable finger on minor claw with concave, spooned out inner surface and red spot under outer mouth part. Habitat Bay, oyster reefs Maximum Size 1 cm (2/5 in carapace width)

Page 32 Gulf grassflat crab Dyspanopeus texanus Family Panopeidae - Mud crabs

Carapace oval anteriorly, posterior lateral sides straight to slightly concave, slightly convex posteriorly, body wider than long; color brownish gray on carapace with dark blotches and small spots, palms of claws pale, fingers light Distinguishing brown with white tips; last legs regular, not flattened; 5 spines on anterior lateral Characteristics edges of carapace; claws unequal in size; major claw with distinct teeth, no single enlarged tooth on movable finger; teeth on minor claw small; carapace finely granular; interorbital with small notch. This crab has no real distinctive features. It lacks a single enlarged tooth on the major claw; no red spot under outer mouth part; no scooped-out finger in minor Similar Species claw; no groove on front margin between eyes; no groove on outer surface of carpus. Habitat Bay, especially on microalgae and seagrasses Maximum Size 2.5 cm (1 in) carapace width Previous Scientific D. texana, Neopanopeus texana Names

Page 33 Gulf squareback crab Speocarcinus lobatus Family Xanthidae - Mud crabs

Carapace almost square, wider than long, slightly wider anteriorly; color whitish with purple to maroon blotches on anterior of carapace, legs and upper surface Distinguishing of claws; last legs regular, not flattened; 5 spines on anterior lateral edges of Characteristics carapace, anterior 2 form a broad lobe slightly concave between; claws about equal in size; no enlarged tooth on movable fingers. Similar Species The square body and purple coloration distinguish this crab from other crabs. Habitat Gulf, probably lives in burrows of worms and crustaceans in the mud Maximum Size 2.7 cm (1 in) carapace width

Page 34 Oystershell mud crab Panopeus simpsoni Family Panopeidae - Mud crabs

Carapace oval anteriorly, widest anteriorly, posterior lateral sides straight, slightly rounded posteriorly, body wider than long; color dark, olive gray to brownish, not solid; claws with characteristic pale mottling; last legs regular, not Distinguishing flattened; 5 spines on anterior lateral edges of carapace, anterior 2 form a Characteristics broad lobe slightly concave between; claws unequal in size; major chela with enlarge tooth on movable finger; white on palms, white on tips of claws; dark red spot under outer mouth parts (3rd maxillipeds) in all male and some females. Distinguished from other local mud crabs by having one enlarged tooth on major claw, immovable finger on minor claw not spooned out on inner surface, Similar Species distinct mottling pattern on claws, and usually (but not always) with red spot under outer mouth part. Habitat Bay, oyster reefs Maximum Size 5.5 cm (2 1/5 in) carapace width Previous Scientific P. herbstii Names

Page 35 Salt marsh mud crab Panopeus obesus Family Panopeidae - Mud crabs

Carapace oval, wider than long; color of carapace blue, maroon, purplish to dark brown, cream color ventrally; last legs regular, not flattened; 5 teeth on anterior lateral edges of carapace, teeth fairly blunt, 5th tooth shorter than 4th; reticulated (spotted) veined pattern on claws, colorless longitudinal stripe on Distinguishing inner and outer palms; major chela with enlarge tooth on movable finger; teeth Characteristics on immovable finger rise above an imaginary line from tip of finger to angle of claw; fingers brown with white tips; eyestalks with alternating longitudinal stripes of dark gray and olive; dark red spot under outer mouth parts (3rd maxillipeds) in both sexes. Most likely to be confused with the oystershell mud crab, P. simpsoni. The oystershell mud crab has a mottled gray color with light colored mottling on the claws. Its lateral teeth are pointed (blunt in salt marsh mud crab).The teeth on Similar Species the immovable claw do not cross an imaginary line from the tip to the angle of the claw. The red spot under its outer mouth part is present in all males but not all females. Bay, marsh edges, shallow intertidal and subtidal waters, burrows in mud Habitat banks Maximum Size 5.6 cm (2 1/5 in) carapace width Page 36 Smooth mud crab Hexapanopeus angustifrons Family Panopeidae - Mud crabs

Carapace oval anteriorly, posterior lateral sides straight to slightly concave, slightly convex posteriorly, body wider than long; color pale to reddish brown on carapace, legs pale, claws with brown on top, rest of claws pale, fingers dark Distinguishing brown with white tips; last legs regular, not flattened; 5 spines on anterior lateral Characteristics edges of carapace; claws unequal in size; major claw with few low teeth, enlarged tooth on movable finger; carapace finely granular; groove on dorsal outer surface of carpus (segment next to claw). Distinguished from other local mud crabs by an enlarged tooth on major claw, immovable finger on minor claw not spooned out on inner surface, no red spot Similar Species under outer mouth part, body paler than most mud crabs, and has groove on dorsal outer surface of carpus (segment behind claw, probably need a magnifier to see). Habitat Gulf, shelled areas or soft sandy bottoms Maximum Size 2 cm (3/4 in) carapace width

Page 37 Stone crab Menippe adina Family Menippidae - Mud crabs

Carapace oval, stout, posterior lateral sides and posterior end slightly curved; color olive to pale background with small darker brown spots in juveniles, color brown in adults; claws with spotting on top, palms lighter, solid reddish brown Distinguishing color; fingers of claws dark brown to nearly black with white at the very tips; Characteristics last legs regular, not flattened; 5 spines on anterior lateral edges of carapace, 2nd and 3rd more lobe-shaped; claws unequal in size; major claw with large tooth on both movable and immovable finger surrounded by smaller teeth. Distinguished from other local mud crabs by having 2 enlarged teeth on major claw (1 on both fingers), immovable finger on minor claw not spooned out on Similar Species the inner surface, no red spot under outer mouth part, dark fingers with white on extreme tips, only mud crab that can exceed 6 cm (2 1/2 in). Habitat Gulf and bay, groins, oyster reefs, rocky areas, jetties and groins Maximum Size 15.5 cm (6 in) carapace width Previous Scientific M. mercenaria Names

Page 38 Pinnotheridae - Pea crabs

Pinnotheridae, the pea crabs, nearly all live in close physical association of other invertebrates, mainly in bivalve mollusk shells and in the tubes or burrows of marine worms or other organisms. Some are parasitic, but many are commensal (living along side their hosts for their own benefit but causing no harm to the host). They are small crabs, usually less than 1/2 in. in width. Many show sexual dimorphism, i.e., a distinct difference in size or appearance between the males and females. There are approximately 7 common species found in Texas.

Page 39 Tube pea crab Pinnixa chaetopterana Family Pinnotheridae - Pea crabs

Carapace oval, more than twice as wide as long, color white but covered with small brown or blackish dense hairs; ridge on posterior margin of carapace, interrupted in the middle with indentation, not extending to the lateral borders of Distinguishing carapace; 3rd walking leg longest and broadest, propodus (next to last Characteristics segment) less than 2 times longer than broad; upper movable finger of claws curved at a 90 degree angle in male, bottom finger short with single tooth near finger; in females the upper finger of claw is straighter and bottom finger is longer. The only other pea crab in the area with similar hooked claws is P. cristata Similar Species which has an uninterrupted ridge that extends to the lateral borders of the posterior end of the carapace. Larger crabs are found in the tubes of the parchment worm, Chaetopterus variopedatus and the ornate worm Amphitrite ornata. Seldom found outside the Habitat tubes. Smaller crabs can be found in the mud burrows of mud shrimps (Callianassa sp.) Maximum Size 1.4 cm (1/2 in) carapace width

Page 40 Porcellanidae - Porcelain Crabs

Porcelain crabs are not "true crabs". They actually evolved from a relative of the squat lobster. The differences between these crabs and true crabs are as follows: porcelain crabs have only 3 pair of walking legs (4th pair small and rudimentary) where true crabs have 4; porcelain crabs lack a wrist segment (carpus) on its claw appendage; and porcelain crabs have very long antennae vs. very short in true crabs. Their abdomens fold under their bodies and move freely. When the crab is alarmed, it sometimes flaps its abdomen to aid in swimming. Their bodies and claws are flat which allow them to hide under rocks and other tight spaces. These crabs easily shed their limbs when caught by a predator or tight squeeze, only to regrow the limb later. A dropped claw may continue to move to distract a predator while the crab makes a getaway.

Porcelain crabs have large claws but do not use them for feeding. They feed by filtering the water for plankton using their feather-like mouthparts. Their claws are used in territorial struggles.

Page 41 Eastern tube crab Polyonyx gibbesi Family Porcellanidae - Porcelain crabs

Carapace smooth, oval, approximately 1/4 to 1/3 wider than long, frontal margin nearly straight; color light with some orange or brown, legs and underside of Distinguishing claws mottled; antennae (not shown in photo) narrow, about 1/2 times longer Characteristics than body; chelipeds (claws) unequal (different sizes), inner margin on 2nd segment (next to claw) concave, scooped out; last outer segment of walking legs with 2 or more spines; claws and legs with fine hairs. Similar Species This is the only one of its species found on the east coast and GOM. Found in the tubes of the parchment worm, Chaetopterus variopedatus. Seldom Habitat found outside the tubes. Maximum Size 1.4 cm (1/2 in) carapace width

Page 42 Green porcelain crab Petrolisthes armatus Family Porcellanidae - Porcelain crabs

Carapace oval, flat, slightly longer than wide; color greenish, light and dark bars on legs; 3 pair of walking legs (4th pair small and usually held under and close Distinguishing to body) and 1 pair of claws; claws flattened; antennae longer than body length; Characteristics no carpus (segment next to claw) on claw appendage; claw appendage with 3- 4 spines on inner lateral surface of merus (arms), no lobe on inner lateral surface. Green porcelain crab has greenish color, no spots or stripes (except banding on legs) and has spines on the inner surface of its claw appendage arm; spotted porcelain crab is brown with white, yellow or blue spots or stripes and Similar Species has a lobe on the inner lateral surface of the claw appendage arm; the striped porcelain crab is light brownish orange with darker mottling on carapace and claws and has 1 small spine on inner surface of claw appendage arm Habitat Gulf and bay, rocky crevices, oyster reefs Maximum Size 1 cm (2/5 in) carapace width,

Page 43 Spotted porcelain crab Porcellana sayana Family Porcellanidae - Porcelain crabs

Carapace oval, flat, slightly longer than wide; color reddish brown with white, yellow or bluish spots or stripes, light bars on legs; 3 pair of walking legs (4th Distinguishing pair small and usually held under and close to body) and 1 pair of claws; claws Characteristics flattened; antennae longer than body length; no carpus (segment next to claw) on claw appendage; claw appendage with lobe on inner lateral surface of merus (arms), no spines on arm; abdomen moves freely. Spotted porcelain crab is brown with white, yellow or blue spots or stripes and has a lobe on the inner lateral surface of the claw appendage arm; green porcelain crab has greenish color, no spots or stripes (except banding on legs) Similar Species and has spines on the inner surface of its claw appendage arm; the striped porcelain crab is light brownish orange with darker mottling on carapace and claws and has 1 small spine on inner surface of claw appendage arm. Habitat Gulf Maximum Size 1.5 cm (3/5 in) carapace width

Page 44 Purse Crabs - Leucosiidae

Purse crabs were named so because their abdomen folds underneath the body (like all true crabs) and forms a large purse-like pocket. The pockets are used to brood egg masses and to protect the egg masses from chafing on the sand as the crab backs in to the sediment to bury itself, leaving only its rostrum extending above the surface. Their bodies are round, and their legs and claw appendages are long and slender. There are usually 2-5 spines at the lateral posterior end of their carapace.

Page 45 Mottled purse crab Persephona mediterranea Family Leucosiidae - Purse crabs

Carapace circular, inflated, anterior end squared off, short; carapace and claws Distinguishing light colored with reddish, brownish or purplish mottling; claw appendages long Characteristics and slender; single line of tubercles (small bumps) defining lateral margin of carapace; 3 spines on the posterior lateral margin of the carapace. Similar to the pink purse crab but has dark mottling color, pink purse crab has Similar Species no mottling. Habitat Gulf, prefers sand or muddy bottoms Maximum Size 6 cm body length (2 1/3 in); common to 2 cm (3/4 in) carapace width Previous Scientific Names P. aquilonaris

Page 46 Pink purse crab Persephona crinita Family Leucosiidae - Purse crabs

Carapace circular, inflated, anterior end squared off, short; color pinkish; claw Distinguishing appendages long and slender; carapace covered with small tubercles (bumps); Characteristics 3 spines on the posterior lateral margin of the carapace. Similar Species Similar to the mottled purse crab but has no colored mottling. Habitat Gulf mostly, bay, prefer sand and shell bottoms Maximum Size 4 cm body length (1 1/2 in), common to 2 cm (3/4) carapace width

Page 47 Hippidae and Albuneidae - Sand and Mole Crabs

Sand and mole crabs are small square or oval-shaped crabs that burrow into the sand in the swash zone (from the highest reaches of waves to the lowest reaches of waves) of sandy beaches, although some may be found in deeper waters. They cannot walk forwards or sideways, only backwards. They use their hind appendages for burrowing and swimming. Sand and mole crabs burrow backwards into the sand so that their head and antennae are near or at the surface. As the tides move in and out, so do the crabs locations. The small bubbling holes you see on the beach are usually sand and mole crab burrows. Unlike other crabs, they have no claws or only have half-claws (subchelate). It was once thought that they catch their food by waving their feathery antennae around to filter the water. However, recent studies have suggested that they are scavengers and predators. They are all marine and are found world-wide except in the Arctic and Antarctica.

Page 48 Mole crab Lepidopa benedicti Family Albuneidae - Mole crab

Carapace squarish, 2 pair lateral spines near anterior margin, front margin with 3 small points, posterior margin with small arc in center; color gray to white, translucent; eye stalks broad, flat, squarish with rounded margins, small teeth on anterior margins, distinct eyespot on notches on lateral margins near the Distinguishing anterior (distal) end; 1 pair of long antennae; 1st pair of legs with sickle-like Characteristics appendage at tip that fold back onto next segment (like a half claw); terminal segment of other legs arc or sickle-shaped; abdomen short, flexed under body, middle segment of tail fan (the telson) is heart-shaped; small hairs on margins of carapace, abdomen and legs. The eyestalks of L. websteri are more oval and have lateral notches and tiny Similar Species eyespots near the posterior (proximal) end of the eyestalks . Mole crabs of the species Albunea have narrow, triangular eyestalks. Habitat Gulf beaches, live in burrows in the intertidal zone and nearshore waters Maximum Size 2.5 cm (1 in) carapace length Other Common Names sand crab Comments Photos courtesy of Ashley Wiseman, TAMUG student.

Page 49 Puerto Rican sand crab Emerita portoricensis Family Hippidae - Sand crabs

Carapace cylindrical, longer than wide; color grayish to brown, hind legs yellowish; antennae feathery, short, reaching just past eye; legs folded close to Distinguishing body; abdomen elongate, pointed on end, flexed under body; carapace with Characteristics transverse lines that fade away on both sides (sides smooth with only traces of lines); head with 3 projections (rostrums); ends of 1st legs pointed, no claws. Mole crabs in the family Albuneidae have scissor-like claws on 1st legs and abdomen is round or heart-shaped (not pointed). The ends of the 1st legs of E. Similar Species talpoida (Atlantic sand crab) are blunt, not sharply pointed. The lines on the back of E. benedicti (Benedict sand crab) continue onto its sides (fade away in the Puerto Rican sand crab). Habitat Gulf beaches, live in burrows in the intertidal zone and nearshore waters Maximum Size 2.5 cm (1 in) carapace width Other Common Names mole crab

Page 50 Spider Crabs - Pisidae

Spider crabs, when juveniles, used hooked setae (hairs on their body) to attach algae, sponges and other invertebrates to their carapace, supposedly for camouflage. There are 2 Pisid crabs in our area, the longnose and the portly spider crabs. Their round bodies and long, thin legs give them the appearance of spiders. Their legs end in curve points which allows them to attach to irregular surfaces. They are found in seagrass beds and on sandy, muddy bottoms. They also have an association with jellyfish, especially cabbageheads, and are often found clinging to the undersides of the jellies.

Page 51 Longnose spider crab Libinia dubia Family Pisidae - Spider crabs

Carapace round, narrowing at the anterior end into an extended, slightly forked Distinguishing rostrum (extended snout); color brown; body tubercled with spines and bumps; Characteristics row of 7 or less (usually 6) spines down the center of the carapace; thin walking legs; tips of legs with curved points; claws small. It's difficult to distinguish between the portly and the longnose spider crabs, except by counting the spines (bumps) down the center of the carapace. The Similar Species portly has 8-9 (the anterior one just small bumps) and the longnose has less than 7 (usually 6).The longnose has a more tear-drop shape, the portly more rounded. Habitat Gulf and bay, seagrass beds, sandy muddy bottoms, attaches to jellyfishes Maximum Size 10 cm (4 in) carapace width

Page 52 Portly spider crab Libinia emarginata Family Pisidae - Spider crabs

Carapace round, narrowing at the anterior end into an extended, slightly forked rostrum (extended snout); color brown; body tubercled with spines and bumps; Distinguishing row of 8-9 spines down the center of the carapace, the anterior few more like Characteristics bumps than spines; thin walking legs; tips of legs with curved points; claws small. It's difficult to distinguish between the portly and the longnose spider crabs, except by counting the spines (bumps) down the center of the carapace. The Similar Species portly has 8-9 (the anterior one just small bumps) and the longnose has less than 7 (usually 6).The longnose has a more tear-drop shape, the portly more rounded. Habitat Gulf and bay Maximum Size Slightly larger than the longnose spider crab (10 cm or 4 in)

Page 53 Swimming Crabs - Portunidae

Portunids are the swimming crabs. Their last pair of legs are modified into flattened, paddle-shaped appendages, called swimmerets, which help the crabs to swim. They usually swim sideways but can also swim backwards and sometimes forward. Their bodies are streamlined for faster swimming. Their carapace is usually flattened and broader than long, the greatest width usually being between the two lateral spines. Most have a series of spines along the lateral margins and between the orbits of the carapace. They have large pincers, usually with spines, to snag and capture fast moving prey. Despite being able to swim, these crabs spend most of their time on the bottom among seagrasses, rocks and reefs or on floating objects. They are opportunistic eaters, eating anything from decaying matter to living organisms. Most of the crabs eaten in restaurants come from this family.

Page 54 Blotched swimming crab Portunus spinimanus Family Portunidae - Swimming crabs

Carapace broader than long, compressed; color dark mottled brown dorsally, white underneath; claws are long, fingers mottled brown, some orange; last pair of legs flattened into paddle-shaped appendages; 9 pair of spines (including the outer orbital spines) along the lateral edges of the carapace, the Distinguishing most posterior pair (called the lateral spines) not much longer than the other Characteristics spines (about twice as long), tips of spines lighter in color; 8 low blunt teeth between the ocular orbits (eye sockets), including the inner orbital teeth, the outer 2 pairs and the inner pair more bi-lobed; spines on the inner margins of merus (2 segments behind claws) and inner and outer dorsal carpus (segment next to claw). The dark brown color, the short lateral spines and the light tips of all Similar Species anterolateral spines distinguish this crab from others. Habitat Mostly Gulf, may be in deeper channels of bays Maximum Size 11 cm (4 1/3 in) carapace width

Page 55 Blue crab Callinectes sapidus Family Portunidae - Swimming crabs

Carapace broader than long, compressed; color olive green to brown dorsally, yellowish to white underneath; legs olive, bluish or brown; claws are long, palms with blue and white coloration, fingers blue in adult males, red or orange in adult females, juveniles with white fingers with red spot at base of fingers; last pair of legs flattened into paddle-shaped appendages; 9 pair of spines Distinguishing (including the outer orbital spines) along the lateral edges of the carapace, the Characteristics most posterior pair (called the lateral spines) being about 3-4 times as long as the others; 4 low blunt spines between the ocular orbits, (eye sockets), including the inner orbit spines; spines on the inner margins of merus (2nd segment from the claws) and outer carpus (segment next to claw), no spine on inner dorsal carpus. Lesser blue crabs look similar, but have 6 low spines between the ocular orbits, Similar Species the center pair extremely small, fingers on claws never red, juveniles with bluish spot at base of fingers. Habitat Bay mainly, shallow Gulf, prefers muddy and sandy bottoms Maximum Size 25 cm (10 in) carapace width, commonly 19 cm

Page 56 Florida lady crab Ovalipes floridanus Family Portunidae - Swimming crabs

Carapace oval, compressed; color orangish brown to gray, joints with darker orangish color; claws long, color brownish with some orange and blue, fingers brown on top, mostly white interiorly; last pair of legs flattened into paddle- Distinguishing shaped appendages; 5 pair of spines (including the outer orbital spines) along Characteristics the lateral edges of the carapace, directed forward; 3 sharp teeth between the ocular orbits (eye sockets), including the inner orbital teeth; small spines on the inner margins of merus (2nd segment from the claws), larger spines on inner and outer dorsal carpus (segment next to claw), the inner spine very long. Similar Species The round shaped carapace distinguishes this crab from other swimming crabs. Habitat Shallow gulf and lower bays Maximum Size 8.5 cm (3 1/3 in) carapace width Previous Scientific O. guadulpensis Names

Page 57 Iridescent swimming crab Portunus gibbesii Family Portunidae - Swimming crabs

Carapace broader than long, compressed; color olive green to brown dorsally, yellowish to white underneath, white spot on each side of lower half of carapace, iridescent patches at base of lateral spines; legs purple or brown with purple tint; claws are long and slender, palms white; fingers in males blue, in females white with brown spot on movable finger; last pair of legs flattened Distinguishing into paddle-shaped appendages; 9 pair of spines (including the outer orbital Characteristics spines) along the lateral edges of the carapace, the most posterior pair (called the lateral spines) being about 3-4 times as long as the others; 8 low blunt teeth between the ocular orbits (eye sockets), including the inner orbital teeth; 4-7 spines on the inner margins of merus (2nd segment from claws) and a small spine on inner and outer dorsal carpus (segment next to claw). The long slender claws, the purplish color and the color patterns on the fingers Similar Species (blue in male, white with brown spot on movable finger in females) distinguish this crab from others. Habitat Gulf and bay Maximum Size 7.5 cm (3 in) carapace width

Page 58 Lesser blue crab Callinectes similis Family Portunidae - Swimming crabs

Carapace broader than long, compressed; color olive green to brown dorsally, yellowish to white underneath; legs olive, bluish or brown; claws are long, palms with blue and white coloration, fingers blue in adult males, violet blue in adult females, juveniles with white fingers with blue spot at base of fingers; last pair of legs flattened into paddle-shaped appendages; 9 pair of spines Distinguishing (including the outer orbital spines) along the lateral edges of the carapace, the Characteristics most posterior pair (called the lateral spines) being the longest; 6 low blunt spines between the ocular orbits (eye sockets), including the inner orbital spines, the center pair of spines very small; spines on the inner margins of merus (2 segments from claws) and outer carpus (segment next to claw), no spine on inner dorsal carpus. The blue crabs look similar, but have 4 low teeth between the ocular orbits, and Similar Species juveniles have a reddish spot at base of fingers. Habitat Gulf and bay Maximum Size 12 cm (4 3/4 in) carapace width

Page 59 Sargassum swimming crab Portunus sayi Family Portunidae - Swimming crabs

Carapace broader than long, compressed; color orangish brown dorsally sometimes with white spots, white underneath; legs orangish brown; claws are long, orangish brown with white spots, fingers orange; last pair of legs flattened into paddle-shaped appendages; 9 pairs of spines (including the outer orbital Distinguishing spines) along the lateral edges of the carapace, the most posterior pair (called Characteristics the lateral spines) being about 3 times as long as the others; 6 low blunt spines between the ocular orbits (eye sockets), including the inner orbit spines; spines on the inner margins of merus (2nd segment from the claws) and a small spine on inner and outer dorsal carpus (segment next to claw). The orangish brown color with white spots and the 6 interorbital teeth Similar Species distinguish this crab from others Habitat Lives among floating sargassum, may be found in the Gulf and the bays Maximum Size 6.5 cm (2 1/2 in) carapace width

Page 60 Speckled swimming crab Arenaeus cribrarius Family Portunidae - Swimming crabs

Carapace broader than long, compressed; color brownish with white spots dorsally, yellowish to white underneath, sometimes with white irregular area in center of carapace; claws are long, color brown with white fingers, last pair of legs flattened into paddle-shaped appendages; 9 pair of spines (including the Distinguishing outer orbital spines) along the lateral edges of the carapace, the most posterior Characteristics pair (the lateral spines) being the longest; 8 low blunt spines between the ocular orbits (including the inner orbit spines), the inner orbit spines bicuspid; spines on the inner margins of merus (arms of claws) and a small spine on inner and outer dorsal carpus (joint of claw). Color pattern distinguishes the specked crab from other crabs, also the inner Similar Species orbital spines are bicuspid, and has a spine on the inner carpus vs. outer carpus in other crabs. Habitat Shallow gulf, common in the surf, prefers sandy or muddy bottoms Maximum Size 12 cm (4 3/4 in) carapace width

Page 61

Arenaeus cribrarius hermit, Longwrist Portly spider crab Armases cinereum hermit, Surf Portunus gibbesii arrow crab, False hermit, Thinstripe Portunus sayi Atlantic ghost crab Hexapanopeus Portunus spinimanus Blotched swimming crab angustifrons Puerto Rican sand crab Blue crab Iridescent swimming crab purse crab, Mottled blue crab, Lesser Isocheles wurdemanni purse crab, Pink Blue land crab lady crab, Florida Red -jointed fiddler crab Blue-spot hermit land crab, Blue Rithropanopeus harrisii box crab, Calico Lepidopa benedicti Saltmarsh mud crab Lesser blue crab box crab, Flecked sand crab, Puerto Rican Libinia dubia box crab, Yellow Sargassum swimming crab Libinia emarginata Smooth mud crab Brown banded hermit Longnose spider crab Calappa sulcata Speckled swimming crab Longwrist hermit Speocarcinus lobatus Calico box crab marsh crab, Squareback spider crab, Longnose Callinectes sapidus Menippe adina spider crab, Portly Callinectes similis Metoporhaphis calcarata Spined fiddler crab Cardisoma guanhumi Mole crab Spotted porcelain crab Clibanarius vittatus Mottled purse crab squareback crab, Gulf Dimpled hermit mud crab, Estuarine Squareback marsh crab Dyspanopeus texanus mud crab, Flatback Stone crab Eastern tube crab Emerita portoricensis mud crab, Oystershell Surf hermit mud crab, Saltmarsh swimming crab, Blotched Estuarine mud crab mud crab, Smooth Eurypanopeus depressus swimming crab, Iridescent Mudflat fiddler crab swimming crab, Sargassum False arrow crab Ocypode quadrata swimming crab, Speckled fiddler crab, Mudflat Ovalipes floridanus Thinstripe hermit fiddler crab, Red-jointed Oystershell mud crab tube crab, Eastern fiddler crab, Spined Paguristes hummi Tube pea crab Flatback mud crab Pagurus annulipes Uca minax Flatclaw hermit Uca rapax Pagurus impressus Flecked box crab Uca spinicarpa Pagurus longicarpus Florida lady crab Pagurus pollicaris Yellow box crab ghost crab, Atlantic Panopeus obesus Giant hermit Panopeus simpsoni grassflat crab, Gulf pea crab, Eastern Green porcelain crab Persephona crinita Gulf grassflat crab Persephona mediterranea Gulf squareback crab Petrochirus diogenes Hepatus epheliticus Petrolisthes armatus Hepatus pudibundus Pink purse crab hermit, Blue-spot Pinnixa chaetopterana hermit, Brown banded Polyonyx gibbesi hermit, Dimpled porcelain crab, Green hermit, Flatclaw porcelain crab, Spotted hermit, Giant Porcellana sayana Marine Shrimps of Texas Page 62

Sand snapping shrimp Bigclaw snapping shrimp Estuarine ghost shrimp Broadspine ghost shrimp Alpheus floridanus Alpheus heterochaelis Lepidophthalmus louisianensis Dawsonius latispina Family Alpheidae Family Alpheidae Family Callianassidae Family Ctenochelidae

Arrow shrimp Peppermint shrimp Ohio shrimp Cinnamon river shrimp Tozeuma carolinense Lysmata wurdemanni Macrobrachium ohione Macrobrachium acanthurus Family Hippolytidae Family Hippolytidae Family Palaemonidae Family Palaemonidae

Brown grass shrimp Daggerblade grass shrimp Marsh grass shrimp Bristled river shrimp Leander tenuicornis Palaemonetes pugio Palaemonetes vulgaris Macrobrachuim olfersii Family Palaemonidae Family Palaemonidae Family Palaemonidae Family Palaemonidae

Roughback shrimp Pink shrimp White shrimp Brown shrimp Rimapenaeus similis Farfantepenaeus duorarum Litopenaeus setiferus Farfantepenaeus aztecus Family Penaeidae Family Penaeidae Family Penaeidae Family Penaeidae

Seabob Asian tiger shrimp Roughneck shrimp Sergestid shrimp Xiphopenaeus kroyeri Penaeus monodon Rimapenaeus constrictus Acetes americanus Family Penaeidae Family Penaeidae Family Penaeidae Family Sergestidae

Lesser rock shrimp Coastal mud shrimp Sicyonia dorsalis Upogebia affinis Family Sicyoniidae Family Upogebiidae

Page 63 Cleaner Shrimps - Hippolytidae Page 64

Cleaner shrimps are named for their habit of removing parasites and diseased tissue from the bodies of other organisms, such as fishes and other crustaceans. In return the hosts provide protection to the shrimps. Sometimes a pair of cleaner shrimps will set up "cleaning stations" where fish who wish to be cleaned can come by and visit. They sometimes even enter the mouths and gills of other fish to clean without the fear of being eaten. A relationship where each organism benefits from the relationship is called symbiosis. Cleaner shrimp can usually be found in many saltwater aquariums where they are used to keep the aquarium clean.

Arrow shrimp Page 65 Tozeuma carolinense Family Hippolytidae - shrimp

Body shrimp-like, long (longer than the rest of the carapace), slender, small, translucent; color usually whitish with pink or reddish tints, but will assume the color of its background; rostrum long, thin, pointed, slightly upcurved, no teeth above, many teeth below; spine on both sides of rostrum at its base; 2nd Distinguishing abdominal segment overlaps the 1st segment; 1st 2 pair of walking legs chelate Characteristics (clawed), 3rd pair never chelate; 1st pair of walking legs thicker but shorter than 2nd pair; carpus (segment next to claws) of the 2nd pair of legs divided into 3 segments; distinct bend in body between the 3rd and 4th abdominal segments; hump on 3rd segment, more distinct in males; last abdominal segment before the telson (tail fan) elongated. The arrow shrimp has a distinct rostrum, including its length and lack of teeth Similar Species on the upper margin. That and its narrow body distinguish it from any other shrimp in the area. Habitat Bay, common in vegetated areas like seagrasses Maximum Size 5 cm (2 in) Other Common Names seagrass arrow shrimp Previous Scientific T. carolinensis Names Comments Swims in a vertical position to camouflage itself among seagrass blades.

Peppermint shrimp Page 66 Lysmata wurdemanni Family Hippolytidae - shrimp

Body shrimp-like; carapace smooth; color white, translucent to transparent, with orange or red lines; 2nd abdominal segment overlaps the 1st segment; 1st 2 pair of walking legs chelate (clawed), 3rd pair never chelate; 2nd pair of legs more slender but longer than 1st pair; carpus (segment next to chela) of the Distinguishing 2nd legs divided into many segments; rostrum short, not reaching to end of Characteristics antennule peduncle (base of the smaller pair of antennae); upper rostrum with 4-5 teeth; 3-5 teeth on lower margin of rostrum; no hepatic spine present; no dorsolateral grooves on posterior carapace or last abdominal segment; 1st 1/2 of body widest, with distinct bend in middle and tapering to tail end; a small shrimp. Easily distinguished by its red stripes., longer 2nd pair of walking legs and the Similar Species carpus on the 2nd leg is divided into many segments. Habitat Gulf Maximum Size 5.5 cm (2 in) Previous Scientific Hippolysmata wurdemanni Names

Page 67 Ghost and Mud Shrimps - Ctenochelidae, Callianassidae and Upogebiidae

Ghost and mud shrimps live in deep, sometimes complex, burrows in intertidal and shallow subtidal waters. Some burrows can exceed depths of 2 m. Their burrowing and water circulation exert a large ecological influence on the sediment structure and geochemistry of environments where they are abundant by dispersing nutrients and oxygen throughout the sediment, which not only benefits them but neighboring organisms as well. Their bodies are long and narrow, more lobster-like than shrimp-like. Their carapace is usually very soft and pliable. They are sometimes used as bait by fishermen who pump the shrimp out of their burrows with a special device.

Broadspine ghost shrimp Page 68 Dawsonius latispina Family Ctenochelidae - shrimp

Body elongate, lobster-like (abdomen dorsoventrally compressed); color pink to orangish with whitish translucent legs and abdominal fan, claw pinkish; one enlarged wide claw, fingers narrow and curved, leaving a space between them; other claw narrow, long but shorter than major claw, fingers narrow, about 1/3 Distinguishing the length of the cheliped; rostrum short, pointed, over 1/2 the length of the Characteristics eye; 1st abdominal segment (the one that attaches to the carapace) narrow, hour-glass shaped; inner appendage (endopod) of tail fan (uropod) only slightly longer than wide and about the same length as the telson (hard middle section of tail fan).. Estuarine ghost shrimp differs from the broadspine ghost shrimp by having a spine on either side of rostrum (anterior lateral border of head) and a telson Similar Species distinctly shorter than the endopods of the tail fan. Other ghost shrimp have a shorter rostrum (<1/4 of eyestalk) and endopods that are 3-4 times longer than wide. Habitat Gulf and bay, prefer muddy bottoms Maximum Size unknown Previous Scientific Callianassa latispina Names

Coastal mud shrimp Page 69 Upogebia affinis Family Upogebiidae - shrimp

Body elongate, lobster-like (abdomen dorsoventrally compressed); color whitish, bluish or yellowish gray; abdomen membranous, not hard or calcified; rostrum broad, triangular shaped, slightly extends past eye; small rounded spine on either side of rostrum; spine on anterolateral border of carapace (next Distinguishing to eye); rostrum and carapace with tiny spines, hairy; claws on 1st pair of legs, Characteristics about the same size, immovable finger of claw smaller than movable finger, both fingers with teeth, hairy; telson (hard middle part of tail fan) broad, truncate, about as long as endopods (paired appendages either side of telson in tail fan). Similar to ghost shrimps, but the rostrums of ghost shrimps are distinctly Similar Species shorter and/or narrower than the eye and the paired claws are of unequal size. Habitat Bay, burrows in mud Maximum Size 10 cm (4 in)

Estuarine ghost shrimp Page 70 Lepidophthalmus louisianensis Family Callianassidae - shrimp

Body elongate, lobster-like (abdomen dorsoventrally compressed); color pink to orangish with whitish translucent legs and abdominal fan; one enlarged wide claw, fingers short, talon-like; rostrum short, pointed, upturned; small spine on Distinguishing anterior lateral border of head, either side of rostrum; 1st abdominal segment Characteristics (the one that attaches to the carapace) narrower on anterior end; inner appendage (endopod) of tail fan (uropod) about twice as long as wide; telson (hard middle part of tail fan) concave, much shorter than rest of tail fan. Broadspine ghost shrimp differs from the estuarine ghost shrimp by having no spines on either side of rostrum (anterior lateral border of head) and a telson Similar Species about the same length as the endopods of the tail fan. Other ghost shrimp have a shorter rostrum (<1/4 of eyestalk) and endopods that are 3-4 times longer than wide. Habitat Gulf and bay, prefer muddy bottoms Maximum Size unknown Previous Scientific Callianassa louisianensis, C. jamaicense,L. jamaicense Names

Palaemonid Shrimps - Palaemonidae Page 71

Palaemonid shrimps live in a wide range of environments, from freshwater to the deep ocean. They have a long rostrum with teeth above and below. Their first two legs are chelate (clawed), the second legs being larger and longer than the first. The carpus (segment next to claw) is undivided, and the second abdominal segment overlaps the 1st and 3rd segment. Most are small, rarely reaching longer than 5 cm (2 in), but some get large enough to be of some commercial value. This family includes many transparent or nearly transparent species. Many are commensal (living on or in another organism without causing harm to the host organism), attracted to hosts such as sponges, corals and anemones. The more colorful ones are able to alter their color to match their background or hosts.

Bristled river shrimp Page 72 Macrobrachium olfersii Family Palaemonidae - grass shrimps

Body shrimp-like; carapace smooth; color reddish brown to dark brown, sometimes speckled with reddish brown; the rostrum (extension on top of head) is straight or slightly curved downward, 12-15 evenly space teeth on upper surface, with 4-5 behind orbit, lower margin with 3-5 teeth; 2rd abdominal segment overlaps 1st and 3rd segments; 1st pair of legs with small claws; 2nd pair of legs unequal in length and differs between sexes: males with one leg Distinguishing that is extremely long (sometimes as long as body) and inflated with a fat claw Characteristics at the end, fingers of claw curved and gaping, females with one leg about 1 1/4 as long as the other, leg and claw are slender, claw curved at the tip; both male and females have hairs and small spines covering the legs and claws and 1 small tooth near the joint; the segment of the leg immediately behind the claw (carpus) is about the same length as the next segment behind it (merus); the carpus on the 2nd leg is whole, not subdivided into smaller segments; hepatic spine present, smaller than antennal spine In the bigclaw river shrimp, M. carcinus, the carpus (segment behind claw) of the second leg is distinctly smaller than the merus (segment behind carpus). In the Ohio shrimp, M. ohione, the tip of the rostrum (extension on top of head) Similar Species has a dagger-like, toothless point. The cinnamon river shrimp, M. acanthurus, has only 2 teeth behind the orbit on the rostrum and the fingers of its claws are covered with a felt-like growth of fine hairs. Habitat Freshwater, bays Maximum Size males to 9 cm (3 1/2 in), females to 6 cm (2 1/5 in) This is a freshwater shrimp, as are all Macrobrachium, that occasionally shows up in the bay. Males of all species are easiest to distinguish because of the Comments differences in the claws between the sexes. Most identification keys only address the males (though they don't always tell you that). Bristled river shrimp have been found in the Guadalupe, San Marcus and Rio Grande Rivers. Brown grass shrimp Page 73 Leander tenuicornis Family Palaemonidae - shrimp

Body shrimp-like; carapace smooth; color brown, orangish; some females with ocelli on 1st and 3rd abdominal segments; 2nd abdominal segment overlaps the 1st segment; 1st 2 pair of walking legs chelate (clawed), 3rd pair never chelate; 2nd pair walking legs and chelae thicker than other legs, carpus (segment next to chela) of the 2nd legs whole, not separated into segments; Distinguishing rostrum wide (high) in females, more slender in males; upper rostrum with 8-14 Characteristics teeth, of which 2 are behind the orbit margin, 5-7 teeth on lower margin of rostrum, partially concealed by setae (hairs), teeth to tip of rostrum; hepatic spine absent; no dorsolateral grooves on posterior carapace or last abdominal segment; 1st 1/2 of body widest, with distinct bend in middle and tapering to tail end; a small shrimp. Differs from penaeids by having the 2nd abdominal segment overlap the 1st segment; differs from the Ohio shrimp by lacking a hepatic spine; Differs from Similar Species other palaemonids by the setae covering the lower rostrum teeth and having more than 4 teeth on the bottom of rostrum. Habitat Gulf, found in floating sargassum or among submerged vegetation Maximum Size 4.7 cm (2 in)

Cinnamon river shrimp Page 74 Macrobrachium acanthurus Family Palaemonidae - shrimp

Body shrimp-like; carapace smooth with short hairs on anterolateral margins; color brown, green or pale yellow, sometimes with red speckles, red or brownish stripe down back, may have irregular red bands on sides; rostrum slightly upcurved, 8-12 teeth on upper margin, 4-7 (usually 6) teeth on lower margin, teeth extend to tip; 1st pair of walking legs (periopods) with small Distinguishing claws; 2nd pair of walking legs (periopods) very elongate, both similar in shape Characteristics and size, rows of spines along the legs to the palm; chelae (claws) elongate, cylindrical, densely covered with hairs, a tooth on the proximal cutting edges of both fingers; last 3 pairs of walking legs (periopods) with small spinules; telson about 1.5 times longer than 6th abdominal segment with 2 pairs of dorsal spines, end has a sharp point in the middle, with 2 pair small spinules on either side, the inner pair extending past the middle point; hepatic spine present. The closest relative in Texas is the Ohio shrimp, M. ohione. The Ohio shrimp is Similar Species a pale gray color, and the tip of its rostrum has a toothless dagger-like point. Habitat Freshwater, low saline areas of the bay Maximum Size 18 cm (7 in)

Daggerblade grass shrimp Page 75 Palaemonetes pugio Family Palaemonidae - shrimp

Body shrimp-like; carapace smooth; color light tan, translucent to transparent; 2nd abdominal segment overlaps the 1st segment; 1st 2 pair of walking legs chelate (clawed), 3rd pair never chelate; 2nd legs longer and more robust than 1st; no teeth on cutting edges of movable or immovable fingers of 2nd legs; carpus (segment next to chela) of the 2nd legs whole, not separated into Distinguishing segments; upper rostrum with 7-10 teeth (usually 8-9), of which 1 is behind the Characteristics orbit margin, 2-4 teeth on lower margin of rostrum, lower teeth at a distance from tip of rostrum, leaving small dagger-like appearance; no hepatic spine present; no dorsolateral grooves on posterior carapace or last abdominal segment; 1st 1/2 of body widest, with distinct bend in middle and tapering to tail end; a small shrimp. Differs from penaeids by having the 2nd abdominal segment overlap the 1st segment; differs from the Ohio shrimp by lacking a hepatic spine (spine on Similar Species cheek); Most similar to marsh grass shrimp but has a dagger-like rostrum tip (no tooth near tip) and only 1 upper rostral tooth behind the orbit margin (2 in the marsh grass shrimp). Habitat Bays, prefers submerged vegetation Maximum Size 5 cm (2 in)

Marsh grass shrimp Page 76 Palaemonetes vulgaris Family Palaemonidae - shrimp

Body shrimp-like; carapace smooth; color light tan or white, translucent to transparent; 2nd abdominal segment overlaps the 1st segment; 1st 2 pair of walking legs chelate (clawed), 3rd pair never chelate; 2nd legs longer and more robust than 1st; movable finger (dactylus) of 2nd leg with 2 tiny teeth on cutting edge, immovable finger with 1 tiny tooth on cutting edge; carpus (segment next Distinguishing to chela) of the 2nd legs whole, not separated into segments; upper rostrum Characteristics with 8-11 teeth, 2 of which are behind the orbit margin, 3-5 teeth on lower margin of rostrum, 1st upper tooth near tip of rostrum; rostrum slightly upcurved; no hepatic spine present; no dorsolateral grooves on posterior carapace or last abdominal segment; 1st 1/2 of body widest, with distinct bend in middle and tapering to tail end; a small shrimp. Differs from penaeids by having the 2nd abdominal segment overlap the 1st segment; differs from the Ohio shrimp by lacking a hepatic spine (spine on Similar Species cheek) and a daggerlike rostrum tip (no tooth near tip); most similar to daggerblade grass shrimp but has a tooth near the tip of the rostrum and 2 upper rostral tooth behind the orbit margin (1 in daggerblade grass shrimp). Habitat Bays, prefers submerged vegetation Maximum Size 4.2 cm (1 1/2 in)

Ohio shrimp Page 77 Macrobrachium ohione Family Palaemonidae - shrimp

Body shrimp-like; carapace smooth; color pale gray with blue spots, 2nd abdominal segment overlaps the 1st segment; 1st 2 pair of walking legs chelate (clawed), 3rd pair never chelate; 2nd pair walking legs greatly elongated (more so in females), longer than other legs, extending past tip of rostrum, claw Distinguishing enlarged; carpus (segment next to claws) of the 2nd legs whole, not separated Characteristics into segments; upper rostrum with 9-13 teeth, of which 3-4 are behind the orbit margin, 1-3 teeth on lower margin of rostrum, lower and upper teeth at a distance from tip of rostrum; hepatic spine present on sides of carapace; no dorsolateral grooves on posterior carapace or last abdominal segment; 1st 1/2 of body widest, with distinct bend in middle and tapering to end of tail. Differs from penaeids by having the 2nd abdominal segment overlap the 1st Similar Species segment; differs from other palaemonids by the presence of a hepatic spine (spine on cheek). Habitat Freshwater, bays Maximum Size 10 cm (4 in) Other Common Names freshwater shrimp

Penaeid Shrimps - Penaeidae Page 78

This family of shrimps contains some of the most valuable commercial species of shrimps. They are characterized by having a well-developed toothed rostrum which extends to or past the eye stalk. Their first three pairs of legs are chelate (clawed) and all five pairs of legs are well developed. They lack a postorbital spine (small spine directly behind the orbit), and their first abdominal segment over laps the second segment. Six species commonly occur in Texas. The three most important commercial shrimps, the brown, pink and white shrimps, use the estuaries for a nursery ground and, when mature, emigrate to the Gulf of Mexico for spawning. Brown and pink shrimps are the small table shrimps usually sold in restaurants. Gulf white shrimps are the jumbo shrimps. A small short-term fishery also exists for the seabobs in the Gulf off northeast Texas. The roughback and roughneck shrimps are small and are not fished commercially, though they might be caught incidentally in other shrimping operations. The imported Asian tiger shrimp is also in this family. These shrimps are raised in Texas on shrimp farms, and occasionally accidental releases into the bays occur. These shrimps have been caught in Texas' waters, but there is no indication that an established population has taken hold.

Page 79 Asian tiger shrimp Penaeus monodon Family Penaeidae - penaeid shrimps

Body shrimp-like, carapace smooth; color grayish green, dark greenish blue, reddish brown in larger specimens, back with alternating dark and light transverse stripes, lighter stripes yellowish to reddish, legs greenish or reddish, sometimes with light and dark banding near body; 1st abdominal segment Distinguishing overlaps 2nd abdominal segment; rostrum with 6-8 teeth above and 3 below; Characteristics rostral crest (ridge on both sides of rostrum) reaches to nearly posterior margin of carapace; no grooves on head next to rostrum, no dorsolateral grooves on the last abdominal segment; 1st 3 pair of walking legs chelate (with claws); telson (triangular terminal segment of the abdomen) with no spines; 5th pair of walking legs with no exopod (thread-like extension) at base. Live and fresh dead are easily distinguished from other shrimp by its color, Similar Species patterning and size (largest known penaeid shrimp). Habitat Gulf and bay, soft bottoms Maximum Size 35 cm (13 3/4 in) Other Common Names giant tiger prawn The Asian tiger shrimp is an invasive species. It is native to the Indo-West Pacific, but it is showing up more and more in the Gulf of Mexico and Texas bays. It's a popular species in the shrimp aquaculture industry, and its appearances in the Gulf are probably from accidental aquaculture releases. Comments The Asian tiger shrimp has the potential to compete with native shrimp for space and food. It preys on small shrimp and fishes and a variety of macroinvertebrates. It is also very susceptible to several deadly shrimp viruses and could possibly spread the diseases to native shrimp populations.

Brown shrimp Page 80 Farfantepenaeus aztecus Family Penaeidae - shrimp

Body shrimp-like; carapace smooth; color brown with some orange or yellow; no lateral spot between 3rd and 4th abdominal segment; 1st abdominal segment overlaps the 2nd segment; rostrum with 8-9 teeth above, 2 teeth Distinguishing below; groove an both sides of rostrum extending almost to posterior edge of Characteristics carapace; dorsolateral grooves on the last abdominal segment broad and well defined; brown pigment on uropods (tail fans) more concentrated on ends; 1st 3 pair of walking legs chelate (with claws). Similar to pink shrimp but pink shrimp have a lateral spot between 3rd and 4th abdominal segment and their dorsolateral groove is so narrow that a fingernail Similar Species cannot fit into it. Brown shrimp differ from white shrimp by having dorsolateral grooves on the last abdominal segment and the dorsolateral grooves on the carapace extend nearly to posterior margin of carapace. Habitat Gulf and bay, soft bottoms Maximum Size 17.5 cm (7 in) Previous Scientific Penaeus aztecus Names

Pink shrimp Page 81 Farfantepenaeus duorarum Family Penaeidae - shrimp

Body shrimp-like; carapace smooth; color pale to dark pink; dark lateral spot at junction of 3rd and 4th abdominal segment; 1st abdominal segment overlaps 2nd abdominal segment; rostrum with 8-9 teeth above, 2 teeth below; groove Distinguishing an both sides of rostrum extending almost to edge of carapace; dorsolateral Characteristics grooves on the last abdominal segment narrow (cannot put fingernail in groove); brown pigment on uropods (tail fans) are evenly dispersed, not concentrated on ends; 1st 3 pair of walking legs chelate (with claws). Similar to brown shrimp but brown shrimp do not have a lateral spot between 3rd and 4th abdominal segment and their dorsolateral groove is broad enough for a fingernail to fit into it. Pink shrimp differ from white shrimp by having Similar Species dorsolateral grooves on the last abdominal segment and the dorsolateral grooves on the carapace extend nearly to posterior margin of carapace. Also white shrimp do not have the lateral spot. Habitat Gulf and bay, soft bottoms Maximum Size 20 cm (8 in) Previous Scientific Penaeus duorarum Names

Roughback shrimp Page 82 Rimapenaeus similis Family Penaeidae - shrimp

Body shrimp-like; sides of carapace and dorsal part of tail rough to the touch; color pinkish translucent with orange spots; rostrum with 7-9 teeth above, no Distinguishing teeth below; 1st abdominal segment overlaps 2nd abdominal segment; Characteristics antennule (smaller antennae) extend well past the rostrum; 1st 3 walking legs chelate, no dorsolateral grooves on last abdominal segment; no dorsolateral grooves on posterior carapace. The roughneck and the roughback shrimp are difficult to tell apart. The roughneck's carapace is smooth to the tough as is its dorsal half of abdomin Similar Species (except for a small band of roughness on either side of dorsal keel on the last abdominal segment). Habitat Gulf, shallow waters Maximum Size 10 cm (4 in) Previous Scientific Trachypenaeus similis Names

Roughneck shrimp Page 83 Rimapenaeus constrictus Family Penaeidae - shrimp

Body shrimp-like; carapace smooth; dorsal part of abdomen smooth except narrow band of roughness on either side of dorsal keel on last abdominal segment; color translucent pink to red, sometimes with reddish streaks; rostrum Distinguishing with 7-9 teeth above, no teeth below; 1st abdominal segment overlaps 2nd Characteristics abdominal segment; antennule (smaller antennae) extend well past the rostrum; 1st 3 walking legs chelate; no dorsolateral grooves on last abdominal segment; no dorsolateral grooves on posterior carapace. The roughneck and the roughback shrimp are difficult to tell apart. The roughback's carapace is rough to the tough as is its dorsal half of abdomin Similar Species (especially the last abdominal segment). The roughneck is usually a darker red with streaks. Habitat Gulf, shallow waters Maximum Size 9.3 cm (3 3/4 in) Previous Scientific Trachypenaeus constrictus Names

Seabob Page 84 Xiphopenaeus kroyeri Family Penaeidae - shrimp

Body shrimp-like; carapace and body smooth; color whitish or yellowish; rostrum as long or longer than carapace with an upward curve, basal part with Distinguishing 5 dorsal teeth above, no other teeth above or below free part of rostrum; 1st Characteristics abdominal segment overlaps 2nd abdominal segment; 1st 3 pair walking legs chelate (with claws); last 2 pair of walking legs extremely long and thin; no dorsolateral grooves on last abdominal segment or posterior half of carapace. Other penaeid shrimp have teeth on the free part of rostrum and their last 2 Similar Species walking legs are not extremely elongate. Habitat Gulf and bay, sandy or muddy bottoms Maximum Size 14 cm (5 1/2 in)

White shrimp Page 85 Litopenaeus setiferus Family Penaeidae - shrimp

Body shrimp-like; carapace smooth; color translucent bluish white; no lateral spot between 3rd and 4th abdominal segment; 1st abdominal segment overlaps the 2nd segment; rostrum with 7-9 teeth above, 2 teeth below; grooves on Distinguishing sides of rostrum short, not extending past anterior half of carapace; no Characteristics dorsolateral grooves on the last abdominal segment; dark blotch on distal end of uropods (tail fans), distal margins outlined with green pigment; 1st 3 pair of walking legs chelate (with claws). Differs from other penaeids by not having dorsal grooves on last abdominal Similar Species segment and dorsal groove on carapace not extending past anterior half of carapace. Habitat Gulf and bay, soft bottoms Maximum Size 20 cm (8 in) Previous Scientific Penaeus setiferus Names

Rock Shrimps - Sicyoniidae Page 86

Rock shrimps resemble penaeid shrimps in size and body shape but are easily distinguished from them by their thick rigid stony carapace. They are nocturnal and are usually found in deeper waters than most commercially caught shrimp. These shrimps were generally not targeted by commercial fishermen because their hard shells made them hard to process in large-scale. In 1969 a Florida man invented a machine that would peel and devein the rock shrimps. Since then there have been directed fisheries to catching these shrimps, although most of it in the Gulf of Mexico is centered around Florida. The rock shrimps are said to have a sweet taste, similar to lobster. There are 2 rock shrimps in Texas waters, the brown and the lesser rock shrimp.

Lesser rock shrimp Page 87 Sicyonia dorsalis Family Sicyoniidae - shrimp

Body shrimp-like; carapace and body thick, rigid; color brownish on back, whitish on sides, dark red/purple spot on 3rd-5th segment; rostrum short, Distinguishing extends horizontally or curved downward to just beyond eye with 3 teeth on Characteristics rostrum (excluding the tip); 2 spines on dorsal carapace behind rostrum; raised dorsal spine directed forward on 1st abdominal segment; strong dorsal spine on last abdominal segment; segments 3-5 sometimes with dorsal spines. The brown rock shrimp has a horizontal rostrum, sides are plain, no spots, and Similar Species 3 spines on dorsal carapace behind rostrum. The lesser rock shrimp is small and does not reach the sizes of the brown. Habitat Gulf, mud and shell bottoms Maximum Size 7.5 cm (3 in)

Sergestid Shrimps - Sergestidae Page 88

Sergestid shrimps are small planktonic nearly transparent shrimps that swim in enormous numbers in the water column. Some are found in shallow offshore waters while many are found in depths of 500-700 m (1600-2300 ft) or more. They are slim-bodied with long slender appendages. They can sometime be so abundant as to form sound-scattering layers. Their predators include fish, whales and squid. Although small in size, they occur in such abundance that they are fished commercially in some countries and used for food or shrimp paste.

Sergestid shrimp Page 89 Acetes americanus Family Sergestidae - shrimp

Body elongate, narrow, shrimp-like; color white translucent, red spots at the base of the abdominal fan; eye stalk long; rostrum elevated, short, 1 spine; 1st Distinguishing abdominal segment overlaps 2nd abdominal segment; 2nd and 3rd pair of Characteristics walking legs with small chelae (claws); 4th and 5th pair of walking legs absent; last abdominal segment elongate, convex (curved outward) on its ventral surface; small, planktonic. Penaeid shrimp have longer rostrums, usually extending beyond the eye and well developed 4th and 5th walking legs; Luciferids have long narrow heads Similar Species and chelae only on the 3rd walking legs; Mysids have greatly reduced feather- like swimming legs. Habitat Gulf and bay, swim in water column Maximum Size 2.6 cm (1 in) Other Common Names paste shrimp

Snapping Shrimps - Alpheidae Page 90

Snapping shrimps are also known as "pistol" shrimps. They are noted for having one oversized claw (usually larger than ½ the body) that is capable of making loud snapping sounds. As the shrimp snaps its fingers shut, a jet of water spurts out, sometimes at speeds of up to 60 mph. The jet causes a low pressure bubble to form. As the bubble collapses, it produces a burst of sound, light and heat for a fraction of a second. The high speed sound can stun larger fishes and kill smaller organisms. The heat generated is nearly equal to the heat given off the sun's surface.

Most snapping shrimps dig burrows and can be found around coral reefs, seagrasses and oyster beds. They are known to share their burrows in a symbiotic relationship with other organisms, most notably gobies. The goby (which has better eyesight than the snapping shrimp) keeps watch for danger and signals the snapping shrimp when danger approaches. Then they both dive into their shared burrow. Snapping shrimps are also known to reverse claws. When the snapping claw is lost, it grows back into a smaller claw, and the minor claw starts growing into the new snapping claw. These shrimps are small, not reaching over 5 cm (2 in) so are of very little commercial value, though they are sometimes used as bait.

Bigclaw snapping shrimp Page 91 Alpheus heterochaelis Family Alpheidae - shrimp

Body somewhat lobster-like (abdomen slightly compressed dorsoventrally); color translucent green, white markings on chelae, legs pale red; rostrum small, pointed, not reaching past eye; eye stalks small, covered by carapace; 1st walking legs thick, chelate (clawed), claws unequal, major chela broad, Distinguishing flattened, notched dorsally and ventrally behind fingers; tip of moveable finger Characteristics curves downward into large tooth; fingers of minor chela long and narrow, about 1/2 the length of the chela, in males a little thicker and more curved at the end; 2nd walking leg weakly chelate; carpus (segment next to chelae) of 2nd walking leg divided into smaller segments. The bigclaw snapping shrimp is distinguished by its greenish color, its wide Similar Species major claw with rounded fingers and has no grooves on back of carapace. Habitat Gulf and bay, live in broken shells or sponges or muddy bottoms Maximum Size 5 cm (2 in)

Sand snapping shrimp Page 92 Alpheus floridanus Family Alpheidae - shrimp

Body elongate, narrow, somewhat lobster-like (abdomen slightly compressed dorsoventrally); color orangish brown; rostrum small, pointed, not reaching past eye; 2nd abdominal segment overlaps 1st segment; 1st pair walking legs thick, long and narrow, chelae (claws) over 1/2 length of leg, major chela laterally Distinguishing compressed with blunt movable finger at tip, finger about 1/3 the length of the Characteristics claw; minor claw with elongate, narrow movable finger, finger over 1/2 length of claw; both claws with setae (hairs); 2nd walking legs ends in small chela; carpus (segment next to chelae) of 2nd walking leg divided into small segments; telson (hard middle part of tail fan) longer than wide. The sand snapping shrimp is distinguished by its narrow but long major claw Similar Species and extremely long fingers on the minor claw (longer than the palm). Habitat Gulf and bay, muddy to sandy bottoms Maximum Size 5 cm (2 in)

Page 93

Acetes americanus Sergestid shrimp Alpheus floridanus Sicyonia dorsalis Alpheus heterochaelis snapping shrimp, Bigclaw Arrow shrimp snapping shrimp, Sand Asian tiger shrimp tiger shrimp, Asian Bigclaw snapping shrimp Tozeuma carolinense Bristled river shrimp Upogebia affinis Broadspine ghost shrimp White shrimp Brown grass shrimp Xiphopenaeus kroyeri Brown shrimp Cinnamon river shrimp Coastal mud shrimp Daggerblade grass shrimp Dawsonius latispina Estuarine ghost shrimp Farfantepenaeus aztecus Farfantepenaeus duorarum ghost shrimp, Broadspine ghost shrimp, Estuarine grass shrimp, Brown grass shrimp, Daggerblade grass shrimp, Marsh Leander tenuicornis Lepidophthalmus louisianensis Lesser rock shrimp Litopenaeus setiferus Lysmata wurdemanni Macrobrachium acanthurus Macrobrachium ohione Macrobrachium olfersii Marsh grass shrimp mud shrimp, Coastal

Ohio shrimp

Palaemonetes pugio

Palaemonetes vulgaris

Penaeus monodon

Peppermint shrimp

Pink shrimp

Rimapenaeus constrictus

Rimapenaeus similis river shrimp, Bristled river shrimp, Cinnamon rock shrimp, Lesser

Roughback shrimp Roughneck shrimp Sand snapping shrimp Seabob

Marine Bivalves of Texas Page 94

Common jingle Mossy ark Turkey wing White miniature ark Anomia simplex Arca imbricata Arca zebra Acer domingensis Family Anomiidae Family Arcidae Family Arcidae Family Arcidae

Eared ark Incongruous ark Transverse ark Blood ark Anadara notabilis Scapharca brasiliana Anadara transversa Lunarca ovalis Family Arcidae Family Arcidae Family Arcidae Family Arcidae

Florida prickly cockle Yellow egg cockle Yellow prickly cockle Giant Atlantic cockle Trachycardium egmontianum Laevicardium mortoni Dallocardia muricata Dinocardium robustum Family Cardiidae Family Cardiidae Family Cardiidae Family Cardiidae

Egg cockle Broad-ribbed carditid Leafy jewelbox Caribbean corbula Laevicardium serratum Carditamera floridana Chama macerophylla Caryocorbula caribaea Family Cardiidae Family Carditidae Family Chamidae Family Corbulidae

Variable coquina Texas coquina Dark false mussel Comb bittersweet Donax variabilis Donax texasianus Mytilopsis leucophaeata Tucetona pectinata Family Donacidae Family Donacidae Family Dreissenidae Family Glycymerididae

Arctic hiatella Smooth flame scallop Buttercup lucine Thick lucine Hiatella arctica Ctenoides mitis Anodontia alba Phacoides pectinata Family Hiatellidae Family Limidae Family Lucinidae Family Lucinidae

Page 95

Tiger lucine Dwarf surf clam Southern surf clam Brown rangia Codakia orbicularis Mulina lateralis Spisula raveneli Rangia flexuosa Family Lucinidae Family Mactridae Family Mactridae Family Mactridae

Channeled duck clam Atlantic rangia Fragile surf clam Smooth duck clam Raeta plicatella Rangia cuneata Mactrotoma fragilis Anatina anatina Family Mactridae Family Mactridae Family Mactridae Family Mactridae

Atlantic paper mussel Hooked mussel American horse mussel Southern ribbed mussel Amygdalum papyrium Ischadium recurvum Modiolus americanus Geukensia granosissima Family Mytilidae Family Mytilidae Family Mytilidae Family Mytilidae

Ponderous ark Concentric nut clam Crested oyster Eastern oyster Noetia ponderosa Nuculana concentrica Ostrea equestris Crassostrea virginica Family Noetiidae Family Nuculanidae Family Ostreidae Family Ostreidae

Western bay scallop Atlantic calico scallop Paper scallop Rough scallop Argopectin irradians Argopectin gibbus Euvola papyracea Aequipecten muscosus amplicostatus Family Pectinidae Family Pectinidae Family Pectinidae Family Pectinidae

Unequal spoonclam Minor jackknife clam Campeche angelwing Angelwing Periploma margaritaceum Ensis minor Pholas campechiensis Cyrtopleura costata Family Periplomatidae Family Pharidae Family Pholadidae Family Pholadidae

Page 96

Atrina seminuda Rough pen shell Saw-toothed pen shell Atlantic kitten's paw Family Pinnidae Pinna rudis Atrina serrata Plicatula gibbosa Half-naked pen shell Family Pinnidae Family Pinnidae Family Plicatulidae

Atlantic pearl oyster Common Atlantic abra White Atlantic semele Stout tagelus Pinctada imbricata Abra aequalis Semele proficua Tagelus plebius Family Pteriidae Family Semelidae Family Semelidae Family Solecurtidae

Green jackknife clam Digitate thorny oyster Elongate macoma Short macoma Solen viridis Spondylus tenuis Macoma tenta Macoma brevifrons Family Solenidae Family Spondylidae Family Tellinidae Family Tellinidae

Tagelus-like macoma Constricted macoma Rose-petal tellin Alternate tellin Macoma tageliformis Macoma constricta Eurytellina lineata Eurytellina alternata Family Tellinidae Family Tellinidae Family Tellinidae Family Tellinidae

Matagorda macoma Texas venus Texas quahog Disk dosinia Macoma mitchilli Agriopoma texasianum Mercenaria texana Dosinia discus Family Tellinidae Family Veneridae Family Veneridae Family Veneridae

Elegant dosinia Southern quahog False angelwing Florida cross-barred venus Dosinia elegans Mercenaria campechiensis Petricolaria pholadiformis Chione elevata Family Veneridae Family Veneridae Family Veneridae Family Veneridae

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Lady-in-waiting venus Sunray venus Puberella intapurpurea Macrocallista nimbosa Family Veneridae Family Veneridae

Page 98 Pholadidae - Angelwings and Piddocks Page 99

Pholadidae, the angelwings and piddocks, have fragile shells that are elongate to oval in shape. The elongated posterior end gapes widely. Sometimes a calcareous plate covers the posterior gape. The dorsal margin on the posterior end and sometimes the anterior end is flared, rolling up and outward. Some, especially the angelwings, have a hard spoon-shaped protuberance extending from underneath the beak (apophysis). The angelwings bore into soft mud. The piddock bore into harder substrates such as shells, driftwood and limestone. Some can cause considerable damage to rocky or wooden structures in harbors and other coastal areas. There are 8 species found in Texas waters.

Angelwing Page 100 Cyrtopleura costata Family Pholadidae - bivalves

Bivalve (2 shells); shell elongate, elliptical, thin and fragile, inflated; shell color white; strong radial ridges of nodules; anterior edge of shell flips up and over beak (the protoplax and mesoplax); no 12 partitions above beak; a spoon- Distinguishing shaped projection (apophysis) on the underside of the beak, hollow at upper Characteristics end; 2 really small muscle scars underneath shell, the pallial line arcs out and downward from posterior muscle (pallial sinus), makes a turn anteriorly at shell's edge (soft V shape), and follows shell edge to anterior muscle. Similar to the Campeche angelwing but the sculpture of the shell is weaker in Similar Species the Campeche angelwing and it has 12 partitions above the beak (absent in the angelwing). Habitat Bay, bore into the mud Maximum Size 17.7 cm (7 in) Comments Can bore into wood, clay, shale and rocks.

Campeche angelwing Page 101 Pholas campechiensis Family Pholadidae - bivalves

Bivalve (2 shells); Shell elongate, elliptical, thin and fragile, inflated; shell color white; anterior edge of shell flips up (protoplax) and over beak (metaplax); transverse plates (mesoplax) protrude above beak forming 12 compartments; weak radial ridges of nodules, stronger at the anterior end than the posterior Distinguishing end (also could appear to some as concentric ridges); short broad projection Characteristics (apophysis) on underside of beak; sharp posterior angle; 2 really small muscle scars underneath shell, the pallial line arcs out and downward from posterior muscle (pallial sinus), makes a sharp turn anteriorly at shell's edge (sharp V shape), and follows shell edge to anterior muscle. Similar to the angelwing (Cyrtopleura costata), but the angel wing has stronger Similar Species larger sculpture on shell and does not have the 12 partitions on beak. Habitat Gulf, bores in the mud Maximum Size 12.8 cm (5 in) Comments Can bore into wood, coral and rock.

Arcidae - Ark Clams Page 102

Arcidae, the ark clams, have shells that vary in shape, from elongate to ovate, usually very inflated. A common characteristic is their radiating ribs. The shells are white or off-white in color but are usually covered by a brownish, hairy outer skin (periostracum). The hinge line is usually long and straight with many small "teeth" or dentations. They are one of the most abundant family of shells found on Texas beaches, probably because some live buried in the shallow, intertidal zones. Others, though, use byssal threads to attach themselves to hard substrates, such as rocks and coral. There are 15 species found in Texas.

Blood ark Page 103 Lunarca ovalis Family Arcidae - bivalves

Bivalve (2 shells); shell round to circular to ovate, inflated, left shell slightly overlaps right shell; color white, has a has a furry, dark brown outer skin Distinguishing (periostracum); strong radial ribs with weak groove in center of ribs; beaks Characteristics curve anteriorly; beaks close together; internal margins deeply scalloped; hinge line slightly arched; hinge teeth all on posterior side of shell, ends at beak anteriorly; ligament on posterior side very narrow. The blood ark can have several shapes. The easiest way to distinguish it from Similar Species other arks is by the hinge teeth. Teeth end anteriorly under the beaks. Also ribs have weak grooves down center. Habitat Gulf and bay, muddy to sandy bottoms Maximum Size 6.4 cm (2 1/2 in) Previous Scientific Anadara ovalis Names Comments Named so because, unlike most mollusks, it has red blood.

Eared ark Page 104 Anadara notabilis Family Arcidae - bivalves

Bivalve (2 shells), shell oval, very inflated, "wings" on both sides of beak; color white, may have brown outer skin (periostracum); anterior end short, rounded; posterior end extended with concave indentation on lateral margin; thick radial Distinguishing ribs; fine concentric ridges in between and across radial ribs giving the ribs a Characteristics beaded appearance; furthest anterior ribs may be grooved down center; hinge long, straight; teeth along length of hinge, largest teeth on posterior end, teeth hug upper hinge edge; interior edges of shell scalloped. Similar in shape to the cut-ribbed ark, A. floridana, but the cut-ribbed ark has grooves down the center of its ribs. The eared ark only has grooves on the anterior most ribs. Also the teeth in the eared ark closely hug the hinge upper margin through its entire length. In the cut-ribbed ark, the anterior teeth slope Similar Species away from the upper margin. In the transverse ark, A. transversa, the hinge teeth hug the upper margin of the hinge except at the ends, both posteriorly and anteriorly, where they slope away. Neither the cut-ribbed or transverse ark have the indented posterior margin. Habitat Bay, sand or muddy bottoms, seagrass beds Maximum Size 5.5 cm (2 1/2 in) Previous Scientific Arca auriculata, Arca deshayesi Names

Incongruous ark Page 105 Scapharca brasiliana Family Arcidae - bivalves

Bivalve (2 shells); shell ovoid, slightly triangular in shape, anterior end bluntly rounded, posterior end more angular; beaks large, separated (not touching) when view from the side, hinge line (edges between beaks) straight on top, slightly curved below; ligature area beneath beak (externally) triangular shaped; shell color white, brown furry covering (periostracum) when alive; heavily Distinguishing beaded radiating ribs on left valve, right valve has smooth radiating ribs, Characteristics beaded only on anterior and posterior ends; beads somewhat elongate (wider than tall); smooth radiating ribs on internal surface; edges of shell crenate (scalloped); left valve overlaps right valve; comb-like teeth on interior of hinge line, teeth becoming smaller towards the center; ventral edge of left shell curved slightly outward when viewed from the ventral side. The incongruous ark is most similar to the triangular ark. The triangular ark has Similar Species beads that are not as oblong (except possibly on sides) and the shell has a straight ventral anterior edge. Habitat Gulf and bay, sandy bottoms Maximum Size 6.2 cm (2 1/2 in) Previous Scientific Anadara brasiliana Names

Mossy ark Page 106 Arca imbricata Family Arcidae - bivalves

Bivalve (2 shells); shell rectangular and elongate; color reddish brown mixed with lighter streaks; hairy brown outer skin (periostracum); hinge area long and straight; radial ridges crossing concentric growth lines, giving a beaded Distinguishing appearance to the shell; strong ridge from beak to posterior margin; anterior Characteristics end rounded, posterior end more squarish with 2 pointed angles; ventral margin of shell with central flexure; beak somewhat pointed, arched gap between beaks. The white miniature ark has a wider beak and weaker flexure (if present) on Similar Species ventral margin and is white. Habitat Gulf, attaches to hard substrates Maximum Size 6.3 cm (2 1/2 in)

Transverse ark Page 107 Anadara transversa Family Arcidae - bivalves

Bivalve (2 shells); shell oblong, wider than long, inflated; color white with brown Distinguishing outer skin (periostracum); strong radial ribs; hinge line long, straight with Characteristics numerous erect teeth; left shell usually beaded on ribs, no beading on right valve; beaks wide, blunt, closer to anterior end; ventral margins scalloped. Similar in shape to the cut-ribbed ark, but the cut-ribbed ark has a groove down Similar Species the center of each rib and concentric ridges between the ribs. Habitat Gulf and bay, sandy bottoms or hard substrates Maximum Size 4.2 cm (1 1/2 in)

Turkey wing Page 108 Arca zebra Family Arcidae - bivalves

Bivalve (2 shells), shell oblong, inflated, almost rectangular shaped; color yellow or white with reddish-brown wavy bands; anterior end short with straight or slightly curved margin, angled at bottom; posterior end extended with Distinguishing concave indentation with upper margin extending past lower margin; dorsal Characteristics (bottom) margin undulating; rounded radial ribs from beaks to margins, with fine ridges between and across ribs; beaks slightly curved inward, widely spaced, area between is flat; hinge long, straight with numerous small teeth. Similar in shape to the mossy ark, A. imbricata. In the mossy ark, the dorsal Similar Species (lower) posterior edge extends past the ventral (upper) posterior edge (opposite in the turkey wing). Habitat Gulf and bay, shell bottoms, reef areas Maximum Size 10 cm (4 in) Previous Scientific A. occidentalis Names

White miniature ark Page 109 Acer domingensis Family Arcidae - bivalves

Bivalve (2 shells); shell elongate, rhomboidal, irregular, moderately inflated, posterior end somewhat pointed; sometimes with wavy margins; color white to Distinguishing off-white or yellowish; strong radial ribs crossed by strong concentric ribs giving Characteristics cancellate (cross-hatched) appearance; ridge from beak to posterior end; beaks curved towards anterior end; posterior end dips downward. The mossy ark has a narrower beak and stronger flexure on ventral margin. It Similar Species also has a reddish brown color. Habitat Gulf, attached to hard surfaces, jetties Maximum Size 3 cm (1 1/5 in) Previous Scientific Barbatia domingensis Names

Noetiidae - Ark Clams Page 110

Genera of this family were once included in the Arcidae (ark clam) family, but were recently placed in the Noetiidae family. Noetiidae shells look similar to the ark clams but differ in ligament placement and the presence of striations on the ligaments. Like ark clams, the shells can be elongate to ovate, inflated, have radial ribs and are whitish with a brown filamentous outer skin (periostracum). There are 2 species found in Texas waters.

Ponderous ark Page 111 Noetia ponderosa Family Noetiidae - bivalves

Bivalve (2 shells); shell ovate, inflated, anterior end rounded, posterior end more angular with nearly straight upper margin; color white, protective covering (periostracum) brown, hairy; interior white, margins crenate (scalloped); Distinguishing flattened radial ribs with fine concentric grooves crossing ribs and in between Characteristics ribs; hinge margin straight on top, slightly curved on bottom; hinge area wide, beak twisted toward posterior end; posterior end with ridge from beak to posterior margin; posterior abductor muscle scar with raised ridge. The flattened ridged posterior end and raised ridge on the posterior muscle Similar Species distinguish this ark. Habitat Gulf and bay, sandy bottoms Maximum Size 7.6 cm (3 in)

Glycymerididae - Bittersweet clams Page 112

Glycymerididae, the bittersweet clams, have round or ovate shells with a hinge area that is wide and arched and teeth that are curved.. They are similar to the ark shells in that they have "taxodont" dentation, meaning they have numerous small teeth that run the length of the hinges. The teeth in the bittersweets are angled upward and outward from the beaks. Bittersweets cannot attach to hard substrates because they have lost the ability to produce byssal threads. Instead they burrow partially in the sandy substrate. They are more active at night. There are 4 species found in Texas waters.

Comb bittersweet Page 113 Tucetona pectinata Family Glycymerididae - bivalves

Bivalve (2 shells); shell ovate, moderately inflated, beak area pointed with slight flare on either side; color white with brown or reddish irregular wavy concentric lines, may have pale brown outer skin (periostracum), interior white with some Distinguishing brown; sculpture of broad radial ribs crossed by narrow concentric growth rings, Characteristics beaks point toward each other; 30-35 ribs; muscle scar with raised inner ridge; hinge area wide, arched; teeth curved, center and end ones smaller; ventral edge crenulate (scalloped). Similar Species Other bittersweets in the Texas area have finer ribs. Habitat Gulf, sand and hard bottoms Maximum Size 2.5 cm (1 in) Other Common Names dog cockles

Carditidae - Carditids Page 114

Carditidae have strong elongate to oval or round shells with strong radiating ribs that may be intersected by concentric scales or ribs. Margins are usually scalloped or toothed. They often attach to substrate using byssal threads. They are unique in that many brood their eggs inside their shells between the inner and outer branches of the gills. One species can be found in Texas.

Broad-ribbed carditid Page 115 Carditamera floridana Family Carditidae - bivalves

Bivalve (2 shells); shell oval, oblong, inflated, thick; color whitish to gray with Distinguishing orange to brown banded markings, interior white; strong radial ribs, ribs beaded Characteristics or scaled; lower margin scalloped; beaks broad, turned towards anterior end; posterior end elongate, slightly angulate but rounded. May be mistaken for an ark shell, the shape of the shell, the coloration, Similar Species beading, and thickness of the shell distinguish it. Habitat Bay, attaches to hard substrates, common in mud flats Maximum Size 3.8 cm (1 1/2 in) Other Common Names broad-ribbed cardita, Florida cardita

Cardiidae - Heart Cockles Page 116

Cardiidae, the heart cockles, have shells that may be circular, triangular or squarish, usually well- inflated. They usually have radial ribs with spines or scales, but some are smooth. The margin of the shells are usually scalloped or serrate. They are readily recognized by being heart-shaped when viewed from either the anterior or posterior side. Teeth along the hinge are large, curving outward. The foot is angular and can be used for "jumping" away from predators. Cardiidae are usually found below the surface in sand or muddy bottoms. There are 13 species found in Texas waters.

Egg cockle Page 117 Laevicardium serratum Family Cardiidae - bivalves

Bivalve (2 shells); shell elongate-oval, sometimes squarish, inflated; color white, brown, yellow or rosy, can be mottled or with concentric streaking, hinge Distinguishing area almost always purple; shell smooth but with minute radial ribs, especially Characteristics on ventral surface, that are difficult to see unless held at the correct angle to the light; low concentric growth rings; inside ventral (lower) margin crenulate (ridged); slight ridge from beak to posterior lower margin. Most other cockles have more well-defined (visible) ribs. A distinguishing Similar Species characteristic of the egg cockle may be the splash of purple on its hinge line which one source says is always there. Habitat Gulf and bay, muddy to sandy bottoms Maximum Size 5 cm (2 in) Previous Scientific L. laevigatum Names

Florida prickly cockle Page 118 Trachycardium egmontianum Family Cardiidae - bivalves

Bivalve (2 shells); shell circular to somewhat oblong in older specimens; moderately inflated; color white to tannish to light brown; interior salmon or pinkish color, sometimes with purple; anterior 1/4 of inside shell white; 27-31 Distinguishing radial ribs on outer shell, ribs scaled, scales scoop-shaped, opening toward Characteristics ventral margin; anterior side of shell with scales that are more solid and round (bead-like); posterior side with a slight rounded ridge from beak to ventral margin, margin of shell serrated. Similar to the yellow prickly cockle (T. muricata) but the scales the yellow prickly cockle are bead-like whereas the scales on the Florida prickly cockle are hollow, scoop-shaped (except on the anterior end where the scales are more bead-like). Also the yellow prickly cockle has more ribs (30-40) than the Similar Species Florida prickly cockle (27-31). Interior color in the Florida prickly cockle is a flush of orangish pink to purple with 1/4 of anterior part white. The yellow prickly cockle's interior is white with streaks of yellow or purple radiating from the beaks. Gulf and bays, sometimes found in seagrass beds, more common in south Habitat Texas Maximum Size 5.1 cm (2 in) Previous Scientific Cardium egmontianum Names

Giant Atlantic cockle Page 119 Dinocardium robustum Family Cardiidae - bivalves

Bivalve (2 shells); shell inflated, shaped round (more rounded when small) to oblique (adults slightly lopsided); color light tannish brown with darker brown Distinguishing markings; interior pink to brown; 32-36 radiating ribs, sometimes with rough Characteristics transverse grooves on anterior ribs, looks scaly; beaks rounded, touching when together; interior with low ridges, edges crenulate, scalloped; flat anterior and posterior lateral tooth on either side of beak, 1-2 curved teeth below beak. Similar Species Other cockles have sharply scaled ribs or no ribs at all. Habitat Gulf, sandy bottoms Maximum Size 12.5 cm (5 in) Other Common Names giant heart cockle

Yellow egg cockle Page 120 Laevicardium mortoni Family Cardiidae - bivalves

Bivalve (2 shells). shell oval to subtriangular, inflated; color whitish or yellowish, many times with variable brownish zigzag design, interior white to Distinguishing yellowish with brown mottling; fine commarginal growth rings with weak radial Characteristics lines; ridge from beak to posterior margin; beak with central (cardinal) tooth flanked on either side by split lateral teeth. The shape and teeth pattern help identify it as a cockle. Most other cockles (except the egg cockles) have strong radial ridges. The regular egg cockle (L. Similar Species serratum) is more elongate and the painted egg cockle (L. pictum) has a more lobsided shape and no radiating lines. Habitat Bay, sandy or muddy bottoms Maximum Size 2.5 cm (1 in) Other Common Names Morton's egg cockle Comments Common duck food. Species can jumb and swim.

Yellow prickly cockle Page 121 Dallocardia muricata Family Cardiidae - bivalves

Bivalve (2 shells); shell inflated, round, slightly taller than wide, become more oblique on the posterior end as it grows; color light cream with patches of Distinguishing brownish red or yellow; interior white to light yellow, sometimes with streaks of Characteristics yellow and/or purple radiating from beaks; edges crenulate or scalloped; 30-40 radiating ribs with beady or disc-shaped scales mostly on the anterior and posterior ends. Similar to the Florida prickly cockle (T. egmontianum) but the scales the yellow prickly cockle are bead-like whereas the scales on the Florida prickly cockle are hollow, scoop-shaped (except on the anterior end where the scales are more bead-like). Also the yellow prickly cockle has more ribs (30-40) than the Similar Species Florida prickly cockle (27-31). Interior color in the Florida prickly cockle is a flush of orangish pink to purple with 1/4 of anterior part white. The yellow prickly cockle's interior is white with streaks of yellow or purple radiating from the beaks. Habitat Gulf and bay, sandy muddy bottoms Maximum Size 7 cm (2 3/4 in) Other Common Names yellow cockle Previous Scientific Trachycardium muricatum Names

Corbulidae - Corbulas Page 122

Corbulidae, the corbulas, have shells that are ovate, oblong or triangular. The posterior end usually tapers to a truncate or angular point and has a rounded ridge from the beak to the posterior point. The outer shell may be smooth but usually has concentric ridges. The right shell is larger and overlaps the left shell. The corbulas can bury themselves or attach to hard substrates. There are 5 species found in Texas waters.

Caribbean corbula Page 123 Caryocorbula caribaea Family Corbulidae - corbulas

Bivalve (2 shells); shell oval, elongate, inflated, sturdy, with concentric ridges; color white or off-white, interior white with orangish brown; valves unequal, right valve overlaps left valve; anterior end rounded; posterior end angulate and Distinguishing slightly concave on ventral edge; posterior end may be squarish in young Characteristics shells; slight ridge from beak to posterior edge; fresh and live specimens with calcified, flat growth extending from posterior margin; beaks small, only slightly angled towards anterior end; no pallial sinus. The contracted corbula and Dietz's rose corbula have a more pointed or more Similar Species oblique posterior edge, and both are white to pink inside. Habitat Gulf and bay, muddy to sandy bottoms Maximum Size 1 cm (2/5 in) in width Previous Scientific C. swiftiana Names

Donacidae - Donax Clams Page 124

Donacidae, the donax clams, have triangular to wedge-shaped shells. The anterior end is narrower than the posterior end. The outer shell is smooth, sometimes with slight radiating ridges. There is a rounded ridge on the posterior end that extends from the beaks to the lower margin. Coloration of the shells vary widely within species. Some even have alternating rays of color and lighter areas. Donaxes live in the upper surface of the intertidal zone of sandy beaches. Receding waves usually expose the clams, which then vigorously bury themselves back into the sand. They are popular in chowders and even eaten raw. There are 2 species found in Texas waters.

Texas coquina Page 125 Donax texasianus Family Donacidae - bivalves

Bivalve (2 shells); shell sturdy, almost triangular in shape, moderately inflated, anterior end longer, both anterior and posterior ends somewhat angular; color Distinguishing whitish with some light blue, pink or yellow; rarely rayed; fine concentric growth Characteristics lines and fine radial ribs; ribs lightly beaded on posterior end; ventral posterior margin crenulate (scalloped), inside ventral margin crenulate. Similar to the variable coquina, but the Texas coquina is smaller (<0.8 cm), Similar Species more inflated, ventral margin is more rounded, left valve overlaps right valve on ventral margin, and its posterior ribs are lightly beaded.. Gulf, bury just beneath the surface of the sand in the surf and shallow subtidal Habitat zones Maximum Size 0.8 cm (1/3 in) Other Common Names fat little donax

Variable coquina Page 126 Donax variabilis Family Donacidae - bivalves

Bivalve (2 shells); shell sturdy, slightly inflated, elongate; anterior end longer and broadly rounded; posterior end short, more angular; bottom edge of posterior end slightly angled upward, margin straight; beak pointed; shell color Distinguishing varies from yellow, rose, pink, pale blue, lavender, tan, brown, and orange, Characteristics sometimes with radiating bands of color, sometimes with purple interiors; shells have fine concentric and radial ridges, radial ridges stronger on posterior end; posterior ventral margin crenate (scalloped), inside ventral margin crenulate. The Texas coquina is smaller (<0.8 cm), more inflated, ventral margin is more Similar Species rounded, left valve overlaps right valve on ventral margin, and its posterior ribs are lightly beaded. Gulf, bury just beneath the surface of the sand in the surf and shallow subtidal Habitat zones Maximum Size 2.5 cm (1 in)

Limidae - File Clams Page 127

Limidae, the file clams, have oval, circular or triangular shells with small "ears" or extensions on either side of the hinge. The sculpture can be smooth, ribbed and/or scaly. The mantle of the organism generally has long sticky tentacles. The file clams can swim like the scallops by flapping their shells and ejecting a stream of water. They swim with their hinge forward, unlike the scallops that swim with the hinge at the back. They can also attach to substrates or build a nest of shell and coral pieces held together by a tangle of byssal threads. There are 7 species found in Texas waters.

Smooth flame scallop Page 128 Ctenoides mitis Family Limidae - bivalves

Bivalve (2 shells); shell oval, narrower towards the beak, only slightly inflated; Distinguishing color whitish, sometimes with a brownish outer protective skin (periostracum); Characteristics slight wings on sides of beaks; over 100 crowded, finely scaled radial ribs that diverge (split off) in the center; interior smooth and shiny. Similar to the rough file clam, C. scabra. The rough file clam has only about 50 ribs with wedge-shaped spines. The Antillean file clam, Limaria pellucida, does Similar Species not have the scaly appearance on its ribs. Its ribs appear more knobby. It does not get as big as the smooth flame scallop (usually only to 1 cm or 2/5 in). Habitat Gulf, attached to hard substrates Maximum Size 8.3 cm (3 1/3 in) Previous Scientific Lima tenera, L. floridana Names

Chamidae - Jewelboxes Page 129

Chamidae, the jewelboxes, have thick, irregular, somewhat circular to oval shells. The surface of the shell is rough and usually have long or short leafy, plate-like or spiny projections. Some attach to hard substrates, and some are free swimming. Most are usually attached to a hard substrate, though maybe temporarily, at some point in their life. The cemented lower valve is usually larger and deeper than the upper valve. Some can have vivid colors while others are just bland. There are 6 species in Texas waters.

Leafy jewelbox Page 130 Chama macerophylla Family Chamidae - bivalves

Bivalve (2 shells); shell circular, inflated, variable depending on the shape of whatever it attaches to; color usually yellow to orange, sometimes pinkish or purplish, may lose its color and become tannish; inside shell white, except Distinguishing around edges; inside margin finely crenulate (scalloped); radiating projections Characteristics from shell flat, leaf-like, projections may be long or short, longer projections may have radial grooves, projections have no regular pattern, very irregular; inside of both beaks with slight overhang (shelf); muscle scars large. Other jewelboxes have small to no projections or have regularly spaced Similar Species projections in rows or radiating ribs. Habitat Gulf, attaches to platforms and other hard surfaces Maximum Size 7.5 cm (3 in)

Anomiidae - Jingle Shells Page 131

Anomiidae, the jingle shells, have shells that follow the shape of the object it lies on or within. It is roughly ovate, shiny, thin and translucent. The lower, attached right valve has a hole in the center from where the shell grew around its byssal threads (which are used to attach to hard surfaces). Color is usually yellowish to orangish. The upper, left valve is usually somewhat convex and has 3 scars on its underside (1 muscle and 2 byssal scars). The 2nd (anterior) muscle was "lost" over time. Although the flesh of the snail is bitter, the outer shell is used in the manufacturing of glue, chalk, paint, shellac and solder and as decorative objects. There are 2 species found in Texas waters.

Common jingle Page 132 Anomia simplex Family Anomiidae - bivalves

Bivalve (2 shells); shell round shaped, slightly inflated, glossy, translucent, thin but sturdy, lower shell is usually flat, upper shell concave; color pale yellow to Distinguishing pale orange, older shells sometime turn black; surface irregular, undulating; Characteristics lower valve with hole near beak through which byssal threads extend to attach to objects; upper shell has large muscle scar opposite hole and 2 smaller byssal scars beneath it Sometimes mistaken for slipper shells on oysters. Slipper shells are single Similar Species shells with a "shelf" underneath. Jingle shells are actually 2 shells. Habitat Gulf and bay, attaches to hard substrates Maximum Size 5 cm (2 in)

Plicatulidae - Kitten's Paws Page 133

Plicatulidae, the kitten's paws, are a small family of bivalves with oval to triangular shells with margins that are strongly crenate, having parallel folds like a fan. They have 1 muscle scar on each shell, similar to the oysters and the scallops which they are closely related to. The right valve is usually cemented to a hard substrate, such as rocks and corals. There is 1 species found in Texas.

Atlantic kitten's paw Page 134 Plicatula gibbosa Family Plicatulidae - bivalves

Bivalve (2 shells); shell fan-shaped, somewhat triangular, posterior end more acute (angulate), anterior end more rounded; color yellowish-white, sometimes Distinguishing with red or brown lines on ribs; thick radial ribs that become broader near the Characteristics ventral edge, giving the margins a zigzag shape; interior muscle scar is colorless and positioned nearer the flared (posterior) end. Can be distinguished from other fluted shells by the size (1 in. or less), its Similar Species triangular shape where the posterior end flares out, and the muscle scar which is colorless and situated on the flared end. Habitat Gulf, attaches to hard substrates Maximum Size 2.5 cm (1 in)

Lucinidae - Lucinas Page 135

Lucinidae, the lucinas, have shells that are circular, white or yellowish, with small centrally located beaks. There's usually a small ridge on the posterior end from the beak to the upper posterior margin. The shell may be smooth or have radial or concentric ridges or both. Lucinas usually live in soft mud or sand, in areas of low nutrients, low oxygen and high sulfide content. Sulfur-oxidizing bacteria in their gills also contribute to their nutrition. Lucinas have a long worm-like foot, that may be 6 times as long as the shell, that pushes through the substrate up to the surface. It is used to make a mucus-lined sandy tube used for water intake. The siphon for exhaling water retracts itself into the shells by inverting itself inside out. There are 11 species found in Texas.

Buttercup lucine Page 136 Anodontia alba Family Lucinidae - bivalves

Bivalve (2 shells); shell circular, moderately inflated; color white to off-white, interior yellowish orange; anterior dorsal margin high on shell with concave area Distinguishing next to beak; posterior dorsal margin juts out at slight angle, then curves Characteristics downward; fine concentric ridges; beak slightly bent anteriorly, small; weak ridge from beak to both posterior and anterior margins; anterior muscle scar elongate, runs parallel to pallial line. Other lucines have more distinct ridges and ribs. The chalky buttercup lucine is Similar Species more inflated, white interior, and its anterior muscle scar lies at a 30° angle to the pallial line (parallel in the buttercup lucine). Habitat Gulf and bay, sand and mud bottoms Maximum Size 6.4 cm (2 1/2 in)

Thick lucine Page 137 Phacoides pectinata Family Lucinidae - bivalves

Bivalve (2 shells); shell round, slightly inflated; color white to light orange, interior white to yellowish, may have slight bumps on interior; irregular concentric ridges, scaly, with concentric growth lines in between; ridges are Distinguishing pronounced and fluted in juveniles; strong ridge from beak to posterior edge, Characteristics posterior edge slightly concave above ridge; ridge from beak to upper anterior end, margin between is double concave; anterior muscle scar elongate, parallel to pallial line. The concave posterior margin and double concave anterior margin Similar Species distinguishes this shell. Habitat Gulf and bay Maximum Size 6.4 cm (2 1/2 in) Previous Scientific Lucina pectinata, L. pectinatus, L. jamaicensis Names

Tiger lucine Page 138 Codakia orbicularis Family Lucinidae - bivalves

Bivalve (2 shells); shell circular, solid, slightly inflated; color white, white to yellowish inside, sometimes with rosy color on beaks and margins; fine radial Distinguishing ribs crossed by fine concentric ridges (cross-hatched look); beak small, pointed, Characteristics angled toward the anterior end; 2 cardinal teeth and 1 anterior lateral tooth in right valve; 2 cardinal and double anterior lateral teeth in left valve; lunule (area in front of beak) small, heart-shaped, mostly only on right valve. The circular shell and the fine cross-hatching is distinctive of the tiger lucine. The dwarf tiger lucine, Ctena orbiculata, has similar cross-hatching but is Similar Species smaller (about 1 in) and has distinct posterior lateral teeth that are only minimal in the tiger lucine. Its lunule is elongate instead of heart-shaped. Habitat Gulf, sand or muddy bottoms Maximum Size 9 cm (3 1/2 in)

Dreissenidae - Closed Mussels Page 139

Dreissenidae, the closed mussels, are a family of fresh and brackish water mussels and includes the highly invasive zebra and quagga mussels. The shells may be triangular or oblong with a narrow pointed beak. One side of the shell is slightly bent inward (concave) while the other side is curved outwards (concave). A shelf-like plate (septum) is located internally below the beak. They attach to hard substrates using byssal threads. Some grow in vast numbers and are known to clog intake pipes, sink buoys (because of the weight) and foul the bottoms of boats and any structure sitting in the water. There is only 1 species found in Texas coastal water, the dark false mussel, and it has not caused any ecological problems, so far.

Dark false mussel Page 140 Mytilopsis leucophaeata Family Dreissenidae - bivalves

Bivalve (2 shells); shell elongate, pointed at hinge area, mussel-like, inflated; color whitish with brown outer protective skin (periostracum); juveniles may Distinguishing have a striped pattern; interior white to bluish gray; shell smooth except for Characteristics concentric growth lines; beak pointed toward anterior end; upper posterior margin nearly straight, with slight angle to a curved ventral margin; shelf on underside of beak; tooth-like projection under shelf. Similar Species The shelf under the beak distinguishes this shell from true mussels. Habitat Bays, attaches to hard substrates Maximum Size 1.8 cm (3/4 in) Other Common Names Conrad's false mussel In the same family as the non-native invasive zebra mussels. Zebra mussels Comments have a more angulate shell.

Mytilidae - True Mussels Page 141

Mytilidae, the true mussels, have oblong shells that are usually narrower at the anterior end, with the beaks set slightly off the anterior end. They attach to hard substrates via their byssal threads and can be found in large colonies and among many other colonial organisms. Some, though, bury themselves in soft substrate. Certain species of mussels are a staple in many seafood restaurants. Although there are 20 species found in Texas, only the hooked mussel grows numerous enough to be collected in any number. However, they are generally too small to be valuable commercially. The invasive brown mussel (Perna perna) was once numerous on jetties and other hard substances in south Texas but slowly disappeared, possibly due to people collecting them as food.

American horse mussel Page 142 Modiolus americanus Family Mytilidae - bivalves

Bivalve (2 shells); shell thin, oblong, moderately inflated, wider at the posterior end than anterior end, shell widest in the center, beak just behind anterior end, lower margin slightly concave; color reddish brown to brown, may have slight Distinguishing purplish tinge; inside smooth, glossy with pink to purple color on ventral half, Characteristics dorsal half bluish white; prominent oblique hump or ridge from beak to posterior margin, sometimes with whitish streak beneath keel; fine concentric growth rings; depression from beak to widest part of shell on ventral margin. Similar Species Similar to the chestnut mussel but more narrow at anterior end. Habitat Gulf, sandy-shelly bottoms, may attach to coral Maximum Size 12.7 cm (5 in) Other Common Names Atlantic ribbed mussel, tulip mussel Previous Scientific Modiolus tulipa Names

Atlantic paper mussel Page 143 Amygdalum papyrium Family Mytilidae - bivalves

Bivalve (2 shells); shell elongate, narrow, fan shaped, narrower at anterior end, Distinguishing delicate and fragile; color grayish to bluish green, sometimes with brownish Characteristics zigzag lines; interior iridescent; shell smooth, no radial ridges; beaks slightly behind anterior end. Similar Species Other mussels have their beaks at the anterior end or are much wider. Habitat Bay, around seagrass roots, inside abandon shells Maximum Size 3.8 cm (1 1/2 in)

Hooked mussel Page 144 Ischadium recurvum Family Mytilidae - bivalves

Bivalve (2 shells); shell elongate, narrow and curved at the dorsal end (beak Distinguishing end); color brown with lighter ribs; radial ribs that split near ventral surface; Characteristics interior shiny, purple to brown, 1 large muscle scar on posterior end; beak pointed, curved toward posterior end; lower margin crenulate (scalloped). Similar Species The only ribbed mussel with a curved, hook-like appearance. Habitat Bay, attached to hard surfaces, especially abundant on oyster reefs Maximum Size 6.3 cm (2 1/2 in)

Southern ribbed mussel Page 145 Geukensia granosissima Family Mytilidae - bivalves

Bivalve (2 shells); shell elongate, wider at posterior end, moderately inflated, beak at anterior end; color brown to black, interior iridescent bluish white; interior posterior margin purplish and crenulate, radiating beaded ribs Distinguishing originating from behind beak; anterior end without radiating ribs, but with Characteristics irregular concentric growth lines; ventral margin slightly to moderately concave; dorsal margin straight for about 3/5 length of shell; anterior muscle scar small; posterior muscle scar elongate. Similar Species Differs from other ribbed mussels by having a non-ribbed anterior end. Habitat Bays, around roots of marsh grasses Maximum Size 10 cm (4 in)

Nuculanidae - Elongate Nut Clams Page 146

Nuculanidae, the elongate nut clams, are marine bivalves that have shells with elongate, usually pointed posterior ends (called a rostrum). They may be smooth or ridged. They also have strong V-shaped lateral teeth on either side of their beaks, separated by a circular or triangular shaped depression (the chondrophore). The organism's foot has two lateral flaps that are used for rapid burrowing. Nut clams usually orient themselves with the anterior end up and then move horizontally through the sediment. They eat detritus that is sucked up from the sediment and filtered through their gills. The are 3 species found in Texas.

Concentric nut clam Page 147 Nuculana concentrica Family Nuculanidae - bivalves

Bivalve (2 shells); shell oblong with an elongated, pointed, posterior margin; anterior end round; color pale yellow to white; fine concentric ridges on ventral (lower) part of shell , becoming smoother towards the beak; inside of beak with Distinguishing small triangular depression (chondrophore); V-shaped, protruding teeth on both Characteristics sides of beak (interior lateral margins); posterior margin usually elongated, curved slightly upward, end narrow and pointed (called a rostrum); radial rib on rostrum nearly smooth, not crossed by strong concentric ridges; inside of shell is dull (not pearly); shell margins are smooth, not finely toothed. The pointed nut clam (N. acuta) is flatter, has thicker, evenly space concentric ridges over the entire shell, and has distinct ridges on the rib of the rostrum Similar Species (posterior end). Another family of nut clams, Nuculidae, have pearly interiors and finely crenulate (saw-like) margins. Habitat Gulf and bays, sandy muddy bottoms Maximum Size 1.8 cm (3/4 in)

Pteriidae - Pearl Oysters Page 148

Pteriidae, the pearl (or winged) oysters, have shells with long flat hinge lines and wing-like extensions on both sides of the hinge. The exterior surface may be smooth or have a series of thin overlapping plates. The interior of the shell is nacreous (having an iridescent luster) which is a source of mother of pearl. Pteriids, especially those in the genus Pinctata, are important sources of natural and cultured saltwater pearls. However, the species found in Texas produce pearls that are generally too small to be of gem quality. Pteriids are not closely related to true oysters. They attach to hard substrates using byssal threads whereas the edible eastern oyster, Crassostrea virginica, "cements" itself to hard objects, as do other oysters. There are 2 species of pteriids found in Texas waters.

Atlantic pearl oyster Page 149 Pinctada imbricata Family Pteriidae - bivalves

Bivalve (2 shells); shell oval with a straight hinge area that is as wide or wider than the rest of the shell; usually with a wing (extension of the hinge area) on posterior end, sometimes on the anterior end; color yellow to brown, Distinguishing sometimes with radiating streaks of alternating dark and light colors; shells Characteristics nearly flat, not very inflated, very thin and delicate; ventral and lateral margins with soft or hardened rounded projections, extending past the margins; part of the surface of shells with scaly projections; interior whitish, pearly (nacreous) in center; brownish around margins. The shape and the scaly surface is usually enough to distinguish this species. Similar Species The Atlantic wing oyster, Pteria colymbus, is of similar shape but has a greatly elongated wing on its posterior end. Habitat Gulf, attached to hard surfaces Maximum Size 6 cm (2.5 in) Other Common Names Caribbean pearl oyster, akoya pearl oyster Previous Scientific P. radiata Names Comments Is capable of producing beautiful pearls. Is cultured in many countries.

Spondylidae - Thorny Oysters Page 150

Spondylidae, the thorny oysters, have circular or ovate shaped shells. The left upper shell has irregular shaped and sized spines. The right valve cements to hard substrates and is flatter than the left valve. The hinges of the shells have interlocking balls and sockets to keep the shells aligned. The thorny oysters are closely related to the scallops, but as in to the "true oysters", their shells are cemented to hard substrates instead of attaching by byssal threads. The mantle of the animal has many sensory tentacles with multiple "eyes" around the shell edges. Many species are very colorful. There are 2 species found in Texas waters.

Digitate thorny oyster Page 151 Spondylus tenuis Family Spondylidae - bivalves

Bivalve (2 shells); shell ovate, slightly inflated, small wings; color brick red to reddish purple, white spot on beaks, internally whitish or yellowish with reddish margins on upper valve, lower (attached) valve with red and yellow blotches Distinguishing internally; radial ribs, some thicker ribs interspaced by narrower ribs; ribs may Characteristics have short spatulate or finger-like spines or may have no spines, just little knobs, most spines will be found on periphery of shell; lower attached shell with flat exterior; interlocking teeth on hinges, teeth on upper shell spread apart, teeth on lower shell together. May be confused with the Atlantic thorny oyster, S. americanus. The Atlantic thorny oyster is more whitish, has longer spines and occurs in deeper water Similar Species than the digitate thorny oyster. The digitate thorny oysters usually occur in 50 ft or less of water. Habitat Gulf, attached to hard substrates Maximum Size 6.4 cm (2 1/5 in) Previous Scientific S. ictericus Names

Ostreidae - True Oysters Page 152

Ostreidae, the true oysters, have very irregular shells, the shape of which is dependent on what it is attached to. The left shell is usually cemented to a hard substrate and is flatter than the right shell. The texture of the outer shell can be smooth to coarse, scaly or with growth rings. Inside, the shell is smooth, white, with a single purple or greenish muscle scar. (Most bivalves have 2 muscle scars on each shell.) The shells are usually encrusted with a variety of organisms, some of which bore into the shell for protection. The true oysters are different from the pearl oyster family, and though they can secret pearls, the results are usually irregular, small and of no value. Ostreidae are valued as food world-wide. There are 5 species found in Texas waters.

Crested oyster Page 153 Ostrea equestris Family Ostreidae - bivalves

Bivalve (2 shells); shell oval to triangular; color usually brownish green (from algae, mud and other encrusting organisms, typically white when all removed); interior pearly with gray to greenish tinge; surface sculpture variable; top shell Distinguishing usually flat; bottom (attached) shell usually deep with elevated margins; Characteristics margins may be smooth or fluted, sometimes with zig zag shape when viewed laterally; muscle scar on inside shell colorless; margins on inside of shell with numerous small parallel ridges or indentations. Difficult to distinguish from the eastern oyster without opening the shells. Sometimes a fluted or zig zag lateral margin helps distinguish the two. Inside the shell, the crested oyster has the small lateral ridges that are absent in the Similar Species eastern oyster, and its muscle scars are colorless (purple in the eastern oyster). The crested oyster only grows to a max of 5 cm (2 in) and prefers saltier water than the much larger eastern oyster. Habitat Bay, in high salinity areas Maximum Size 5 cm (2 in) Other Common Names horse oyster

Eastern oyster Page 154 Crassostrea virginica Family Ostreidae - bivalves

Bivalve (2 shells); shell usually oval, possibly wider at the unhinged end, thick, irregular, sometimes with concentric rings, shell can be scaly, can grow to any shape necessary; shell color usually gray, can have greenish or reddish tinge Distinguishing due to algae; can have many encrusting organisms on shell, including spat Characteristics (larval oysters); usually attaches to other oysters to build reefs but can attach to any hard surface; beaks long, sometimes curved; upper valve shorter, flatter and smoother than lower valve; hinge attachment sight usually out of sight in between both valves; inside smooth, white with purple muscle scar. The eastern oyster is most similar to the crested oyster which is smaller (maximum size about 51 cm or 2 in), round, and resides in more saline water Similar Species than the eastern oyster. The main distinction is that crested oysters have teeth on the upper interior lateral margins (absent in eastern oysters) and colorless muscle scars. Habitat Bay, usually occur as reefs Maximum Size 22 cm (8 3/4 in)

Pinnidae - Pen Shells Page 155

Pinnidae, the pen shells, have thin, fan-shaped, translucent shells. The outer shell may have radial ribs and or small scales or spines. The inside has a shiny, iridescent part called the nacreous layer (or nacre). The hinge is long and straight. They live partially buried in muddy, sandy or shelly substrates, with the rounded end exposed, by about 1 inch, and agape. Byssal threads are used to attach to the substrate. The shells are very fragile and are difficult to find intact while beachcombing, let alone get it home without breaking it. There are 5 species found in Texas.

Half-naked pen shell Page 156 Atrina seminuda Family Pinnidae - bivalves

Bivalve (2 shells); shell wedge or fan-shaped, slightly inflated, very fragile, translucent; beak pointed; color tan sometimes with purple-brown markings; Distinguishing hinge area long, straight from beak to posterior end of shell; 10-15 radiating Characteristics ribs (smooth or with tubular spines) on upper (dorsal) portion of shell; ventral portion usually smooth with no ribs; ventral margin of shell curved at posterior end; interior muscle scar well below edge of nacreous (shiny) layer. Has less ribs and larger spines (if present) than the saw-tooth pen shell. Similar Similar Species to stiff pen shell, but interior muscle scar on thestiff pen shells borders the edge of the nacreous layer. Habitat Gulf and bay, sandy to muddy bottoms Maximum Size 23 cm (9 in)

Rough pen shell Page 157 Pinna rudis Family Pinnidae - bivalves

Bivalve (2 shells); shell wedge or fan-shaped, slightly inflated, very fragile, translucent, beak pointed; color pinkish orange; hinge area long, straight; low, Distinguishing broad, rounded ribs, sometimes with scaly projections; interior with nacreous Characteristics (shiny) layer, divided by a shallow groove longitudinally, the dorsal lobe of the layer is longer than the ventral lobe. Similar to the amber pen shell, P. carnea, but the amber pen shell is narrower Similar Species and the ventral lobe of the nacreous layer is slightly longer than the dorsal lobe. Other pen shells do not have a divided nacreous layer. Habitat Gulf, attached to hard surfaces. Maximum Size 56.5 cm (22 1/4 in) Other Common Names Rude pen shell Has been found at Stetson Bank near the Flower Gardens Banks. Specimens Comments in the photographs were found attached to a buoy rope that washed ashore at Surfside Beach, TX.

Saw-toothed pen shell Page 158 Atrina serrata Family Pinnidae - bivalves

Bivalve (2 shells); shell wedge or fan-shaped, slightly inflated, very fragile, translucent, beak pointed; color greenish to tan; hinge area long, straight, Distinguishing slightly concave near beak; 30-40 thin radial ribs becoming smoother near Characteristics ventral (opposite hinge) end; fine sawtooth serrations covering most of shell; interior muscle scar well below edge of nacreous (shiny) layer. Differs from the stiff pen shell which has its interior muscle bordering the edge Similar Species of the nacreous layer. Differs from the half-naked pen shell by having more ribs (30-40 vs. 10-15) and having smaller tube-like spines. Habitat Gulf and bay, sandy to muddy bottoms Maximum Size 30.5 cm (12 in)

Solenidae, Pharidae and Solecurtidae - Razor Clams Page 159

These three families are typically known as “razor clams”. Solecurtidae, the short razor clams, have shells that are stout, rectangular, long and narrow. The outer shell is smooth, sometimes with fine concentric growth lines. The shells may be covered by a thin brown outer skin (periostracum). Both anterior and posterior ends are widely gaping. These shells somewhat resemble the tellins but don't have the posterior twist in their beaks like the tellins do. They bury themselves in soft mud, and their burrows can be fairly deep, up to 50 cm (20 in) beneath the surface. Their siphons can extend many times the shell length to reach the sediment surface. There are 3 species of Solecurtidae found in Texas waters.

The jackknife clams (Solenidae and Pharidae) have small, smooth shells that are long, narrow and very fragile. The hinges occur near the anterior end of the shell. The edges of their shells can be razor sharp. They have a strong muscular foot that allows then to burrow quickly into sandy bottoms and are generally found in the intertidal and high subtidal zones. Some have hemoglobin-like oxygen storing molecules, similar to some arks, that contain a red pigment that resembles blood. All of these clams are edible. There is one species in each family found in Texas waters.

Green jackknife clam Page 160 Solen viridis Family Solenidae - bivalves

Bivalve (2 shells); shell elongate, somewhat flat (slightly inflated), thin and fragile; color translucent white with glossy greenish or brownish outer skin Distinguishing (periostracum), sometimes with faint brown streaks from dorsal to ventral sides; Characteristics hinge and beak at anterior end; 1 tooth at hinge in each valve; dorsal side nearly straight, ventral side slightly curved. Similar to the minor jackknife clam, Ensis minor, which is narrower, longer, Similar Species more curved and has 2 teeth in the hinge of the left valve. Habitat Gulf and bay near Gulf inlets, shallow sandy flats Maximum Size 5 cm (2 in) Other Common Names green razor clam

Minor jackknife clam Page 161 Ensis minor Family Pharidae - razor clams

Bivalve (2 shells); shell elongate, slightly inflated, ends truncate to slightly rounded, thin, fragile; color whitish to light brown, sometimes with a greenish tinge, a triangular area of transverse brownish lines starting hinge area down to Distinguishing posterior end, apparent in most fresh individuals; hinge near anterior end; Characteristics dorsal edge (side with hinge) may be straight or slightly curved; shells gaping at both ends; length of shell greater than 5 times the width; hinge area of left valve with 2 vertical teeth and 1 low lateral tooth, right valve with 1 vertical and 1 low lateral teeth; The length of the green jackknife clam, S. viridis, is less than 5 times the width, Similar Species and it has only 1 vertical tooth in the left valve. Habitat Gulf and bay, around edges of bays and lagoons Maximum Size rarely exceeds 7.6 cm (3 in)

Stout tagelus Page 162 Tagelus plebius Family Solecurtidae - bivalves

Bivalve (2 shells); shell elongate, rectangular; slightly inflated, color white, has brown outer protective skin (periostracum); beaks central or slightly posterior to Distinguishing central, low, barely distinguishable from upper margin; slight curved radial ridge Characteristics on posterior end; minute concentric growth rings; upper inner margin behind beak has narrow ridge or shelf were ligament attaches. The purplish tagelus has more rounded anterior and posterior ends and has a Similar Species radial ridge on the inside central part of shell (lacking in stout tagelus). Habitat Bay, around the shoreline Maximum Size 9 cm (3 1/2 in) Other Common Names stout razor clam, spit clam Comments Burrows into mud vertically. squirts water in the air when the tide is out.

Hiatellidae - Rock Borers Page 163

Hiatellidae, the rock borers, have oblong, irregular shaped shells, usually with wavy concentric growth lines. They commonly bore into sponges, corals and limestone. Some like to burrow into soft substrates. This family includes the Pacific geoduck (pronounce goo-ee-duck) that is the largest American clam. Its shell reaches 9 inches and its siphon may stretch to 2 feet. There are 2 species of Hiatellidae found in Texas.

Arctic hiatella Page 164 Hiatella arctica Family Hiatellidae - bivalves

Bivalve (2 shells); shell elongate, irregular margins; color chalky white; beaks Distinguishing about 1/3 back from anterior end; posterior end with weak radial ridge, may Characteristics look scaly; weak, irregular concentric growth lines; small clam. Similar Species The mossy ark has irregular shaped margins but has distinct beaded ridges. Habitat Gulf and hypersaline bays; bores into soft rock, mud, sand or existing crevices Maximum Size 2.5 cm (1 in) Comments Shape is highly variable because of its boring habits.

Pectinidae - Scallops Page 165

Pectinidae, the scallops, have shells that are ovate, fan-like (narrower at the beaks), with flat projections (called "wings" or "ears") either side of the beaks. Most have radiating ridges that may or may not be scaly. Some attach to soft substrate using byssal threads. Others just lay on the soft sediment. When disturbed, they can flap their valves and "swim" away from predators. This family, along with the true oysters (Ostreidae), have only 1 muscle (thus 1 muscle scar) compared to most bivalves that have 2 muscles. Many species are of important commercial value as food, as well as in shell collecting. There are 8 species found in Texas waters.

Atlantic calico scallop Page 166 Argopectin gibbus Family Pectinidae - bivalves

Bivalve (2 shells); shell circular, fan-like, slightly inflated, with extensions or wings on either side of beaks, wings equal in length; color white with reddish purple blotching, usually with lighter colored rib in the center, right shell with Distinguishing less coloration (mostly white) than left shell, many variations of color and Characteristics patterns; 17-23 (usually 20) strong radiating ribs, grooves between ribs on left shell with tiny concentric threads; beak central, pointed; insides with reddish brown on upper portion, strong radiating grooves; left shell slightly more convex or inflated than right shell. The circular shape with equal length wings, and the light background with various mottling usually distinguishes this scallop. The bay scallop is usually a Similar Species solid color with white interior and the right shell (which is usually white) is distinctly more convex than the left shell. Also, the bay scallop has 12-17 ribs while the calico scallop has 17-23 (excluding the wings). Habitat Gulf and high salinity bays, free-living, does not burrow Maximum Size 6 cm (2 1/3 in) Comments Rarely found north of Port Aransas.

Paper scallop Page 167 Euvola papyracea Family Pectinidae - bivalves

Bivalve (2 shells); shell circular, fan-like, slightly inflated to nearly flat; shell Distinguishing fragile; extensions or wings on either side of beak are small; color reddish Characteristics brown with radial streaks; bottom valve whitish with yellow or white edges; outer shell smooth, no radial ridges; inner shell with paired radiating ridges. Similar Species Other scallops in the Gulf have strong radiating ribs on the outer shell. Habitat Gulf, shelly or muddy bottoms Maximum Size 5.1 cm (2 in) Previous Scientific Amusium papyraceum Names

Rough scallop Page 168 Aequipecten muscosus Family Pectinidae - bivalves

Bivalve (2 shells); shell circular, fan-like; extensions or wings on either side of Distinguishing beak are unequal, anterior wing longer; color from reddish orange to orange- Characteristics brown to yellow; 18-20 radial ribs with low spines or scales along the center, smaller spines on either side of ribs and in between. Similar Species Other scallops lack the spines or scales on the radial ribs. Habitat Gulf, sand or sandy mud bottoms, free-living, does not burrow Maximum Size 3.2 cm (1 1/4 in) Previous Scientific A. exasperatus Names

Western bay scallop Page 169 Argopectin irradians amplicostatus Family Pectinidae - bivalves

Bivalve (2 shells); shell circular, fan-like, with extensions or wings on either side of beaks, wings equal in length when not broken or worn down; moderately Distinguishing inflated, right shell more inflated than left; color brown to gray on left (top) shell, Characteristics lighter in between ribs; right (bottom) shell white, no markings; 12-17 strong radial ribs; fine concentric lines, more prominent between ribs in larger shells, runs over ribs in smaller shells; ventral edges scalloped. The calico scallop has a light background with various mottling and a reddish upper interior. The bay scallop is usually a solid color with white interior and the Similar Species right shell (which is usually white) is distinctly more convex than the left shell. Also, the bay scallop has 12-17 ribs while the calico scallop has 17-23 (excluding the wings). Habitat Bays, on mud and sandy bottoms, free-living, does not burrow Maximum Size 10.2 cm (4 in) There are 3 varieties of A. irradians in the Gulf of Mexico. A. irradians Comments amplicostatus does not occur east of the Mississippi River.

Semelidae - Semeles Page 170

Semelidae, the semeles, have shells that are round or oval and are somewhat flattened. The anterior end is longer, generally rounded and the posterior end is short and sometimes truncate or slightly angular. The outer shell is usually smooth but may have fine concentric or radial ribs or both. They usually bury themselves in soft sand or mud. There are 10 species found in Texas waters.

Common Atlantic abra Page 171 Abra aequalis Family Semelidae - bivalves

Bivalve (2 shells); shell circular with small, pointed beak, inflated, smooth; 2 forms, thick-shelled and thin-shelled; color white or off-white; anterior end Distinguishing round; posterior end with slight angle; left shell with ridge from beak to posterior Characteristics end; pallial sinus large, rounded, nearly reaching beaks; lateral teeth in right valve; no lateral teeth in left valve; small groove extension (chondrophore) extends posteriorly from beak. Similar to the white Atlantic semele in shape, but the abra's shell is more Similar Species smooth. Habitat Gulf and bay Maximum Size 0.6 cm (1/4 in)

White Atlantic semele Page 172 Semele proficua Family Semelidae - bivalves

Bivalve (2 shells); shell round, slightly inflated; color white to light yellow, sometimes with darker speckles; has concentric growth lines that are strongest Distinguishing on the ventral surface; weak radial lines; beaks pointed, almost central, pointing Characteristics forward; upper anterior and posterior margins almost straight, other margins rounded; pallial sinus round, large, oblique (angled); small groove internally posterior to beak (chondrophore) to hold ligament. Similar to the common Atlantic abra in shape, but the abra's shell is more Similar Species smooth. Habitat Gulf and bay, sandy areas Maximum Size 4 cm (1 1/2 in) width

Periplomatidae - Spoon Clams Page 173

Periplomatidae, the spoon clams, have round to ovate shells with a ridge or crease on the posterior end from the beak to the ventral edge. They are usually pearly white, small and fragile. Interiorly, they have prominent spoon-shaped chondrophores than hang down beneath the beak. They also have a hardened nodule (ossicle) beneath the beak, above the chondrophore. There are 2 species found in Texas.

Unequal spoonclam Page 174 Periploma margaritaceum Family Periplomatidae - bivalves

Bivalve (2 shells); shell somewhat rectangular, fragile, inflated; color white; Distinguishing anterior end longer and more rounded than posterior end; beaks small, near Characteristics posterior end; posterior end with radial ridge; posterior margin truncate, almost straight; spoon-shaped projection under beaks, pointing anteriorly. Similar Species The shape of this shell is pretty distinct from other shells. Habitat Bay, around the shoreline Maximum Size 2.5 cm (1 in)

Mactridae - Surf Clams Page 175

Mactridae, the surf clams, have shells that are oval, triangular or oblong. The outer shell may be smooth or have concentric ridges. Many have a rounded ridge on its posterior end. In the beak of the shells is an oval pocket (chondrophore) which holds the internal ligaments. The surf clams burrow in sandy or muddy bottoms. Many are very common and tend to dominate, in numbers, the areas where they are found. Many are of commercial importance. Some, like the Rangia shells, are commonly used as road-bed material. There are 7 species found in Texas waters.

Atlantic rangia Page 176 Rangia cuneata Family Mactridae - bivalves

Bivalve (2 shells); shell heavy, somewhat triangular; anterior end broadly rounded; posterior end rounded but more angular; color whitish but covered with a blackish to brown exterior coating (periostracum); shell with concentric Distinguishing ridges and grooves; beak near rounded anterior end, twisted anteriorly; small Characteristics gap between beaks; interior white; pallial sinus small; enlarge tooth near beak in both shells; posterior inner margin with long ridge (lateral tooth) from beak to near posterior end. Similar to the brown rangia, but the brown rangia has an angular pointed posterior end, very small or no pallial sinus and a shorter ridge (lateral tooth) on Similar Species posterior margin. May be confused with the southern or Texas quahog, but the quahogs have no gap between its beaks and have a short, rounded depression (lunule area) just anterior to both beaks (no lunule in rangia). Habitat Bays, low salinities, freshwater Maximum Size 9.4 cm (3 3/4 in)

Brown rangia Page 177 Rangia flexuosa Family Mactridae - bivalves

Bivalve (2 shells); shell heavy, somewhat triangular; anterior end broadly rounded; posterior end angular, pointed; distinct ridge from beak to posterior end; color whitish but covered with a blackish to brown exterior coating Distinguishing (periostracum); shell with concentric ridges and grooves; beak near rounded Characteristics anterior end, twisted anteriorly; small gap between beaks; interior white; pallial sinus minute or absent; enlarged tooth near beak in both shells; inside posterior margin with short ridge (lateral tooth), does not reach posterior end. Similar to the Atlantic rangia, but the Atlantic rangia has a rounded posterior end, a larger pallial sinus ( small to no sinus in the brown rangia) and a longer ridge (lateral tooth) on posterior margin. May be confused with the southern or Similar Species Texas quahog, but the quahogs have no gap between its beaks and have a short, rounded depression (lunule) just anterior to both beaks (no lunule in rangia).. Habitat Bays, low salinities, freshwater Maximum Size 7.5 cm (3 in) Previous Scientific Rangianella flexuosa Names

Channeled duck clam Page 178 Raeta plicatella Family Mactridae - bivalves

Bivalve (2 shells); shell somewhat triangular, moderately inflated, posterior end narrow and angular, anterior end broad and rounded, very fragile shell; color white; prominent, widely spaced concentric ridges, also apparent on the inner Distinguishing shell; hinge has a spooned-out depression for the inner ligament; has a radial Characteristics ridge on the upper posterior margin, sometimes a lower ridge anteriorly; the posterior end has a gap between the 2 shells; the beak is pointed and points toward the narrow posterior end. All surf clams have the scooped out hinge and posterior radial ridge, but the Similar Species channeled duck clam is the only one with the prominent concentric ridges. Habitat Gulf, sandy bottoms of outer surf zones Maximum Size 7.5 cm (3 in)

Dwarf surf clam Page 179 Mulina lateralis Family Mactridae - bivalves

Bivalve (2 shells); shell triangular, tiny, inflated, anterior end rounded, posterior end more angulate; color white or off-white; radial ridge from beak to ventral Distinguishing edge of shell on posterior end; fine concentric growth rings; beaks in center of Characteristics shell; hinge has a spooned-out depression (chondrophore) for the inner ligament attachment. May resemble juvenile southern surf clam (Spisula raveneli). Differs by having Similar Species a stronger posterior ridge and more angular posterior end. The southern surf clam is usually more brownish in color. Habitat Gulf and bay, sand and mud bottoms Maximum Size 2 cm (3/4 in)

Fragile surf clam Page 180 Mactrotoma fragilis Family Mactridae - bivalves

Bivalve (2 shells); shell wider than high, oval shaped, thin, fragile, slightly inflated; color whitish, possibly with a grayish skin (periostracum); fine irregular concentric growth lines; beak central, slightly anterior of shell; posterior and Distinguishing anterior margins rounded; ridge from beak to posterior margin; posterior end Characteristics curved outward, producing gape; pallial sinus moderately large, rounded, reaching mid-shell; interiorly beak area with 1 or 2 depressions (chondrophore) flanked by small projecting teeth. Its rounded margins, central beak, and fine commarginal ridges help separate Similar Species the fragile surf clam from other surf clams. The teeth and chondrophores help distinguish it from other clams. Habitat Bays, mud bottoms Maximum Size 9 cm (3 1/2 in) Previous Scientific Mactra fragilis Names

Smooth duck clam Page 181 Anatina anatina Family Mactridae - bivalves

Bivalve (2 shells); shell oblong, somewhat triangular, fragile, moderately inflated; color white to light yellow; fine irregular concentric growth lines, tiny but distinct concentric ribs near the beak; distinct ridge from beak to posterior Distinguishing margin; beak points posteriorly; scooped out shelf (chondrophore) under beak, Characteristics distinct groove anterior to chondrophore, slight groove posteriorly; posterior end curved to the right, edges flared and gaping; pallial sinus short but wide slightly angled upward. Similar in shape to the channeled duck clam, but its concentric ribs are small Similar Species and more closely spaced the channeled clam. Habitat Gulf, sand to sandy mud bottoms Maximum Size 7.6 cm (3 in) Previous Scientific Labiosa lineata Names

Southern surf clam Page 182 Spisula raveneli Family Mactridae - bivalves

Bivalve (2 shells); shell oval, triangular, somewhat inflated; color white to light yellow, interior white; shell smooth except for fine concentric growth lines, somewhat roughened on the posterior end; beaks pointed, almost central; Distinguishing scooped out shelf (chondrophore) underneath beak (chondrophore not well Characteristics developed in juveniles); interior lateral margins on either side of beak each with 2 elongate teeth with long groove in between; both abductor muscle scars above midpoint of shell; pallial sinus wide, short, thumb-like. Similar Species The triangular shape helps distinguish this shell from other surf clams. Habitat Gulf, sandy bottoms Maximum Size 17.8 cm (7 in) Other Common Names Atlantic surf clam Previous Scientific Sp. solidissima, Mactra solidissima Names

Tellinidae - Tellin Clams Page 183

Tellinidae, the tellins, have shells that are round to oblong in shape and are usually thin and flattened. The anterior end is rounded, and the posterior end is more elongate. Their surfaces are usually smooth but may have fine concentric or radial ridges. Tellins bury themselves, usually lying horizontally on their left valve which allows the right valve to become more inflated. They extend their siphons up through the mud to the surface to suck up edible bits while they remain safely buried. Tellin clams also have hemoglobin which give the animal a bright red color. They are important as food sources and, because of the coloration on some of the shells, in shell collecting. There are 25 species found in Texas waters.

Alternate tellin Page 184 Eurytellina alternata Family Tellinidae - bivalves

Bivalve (2 shells); elongate, somewhat triangular, flattened, posterior end narrower and slightly truncate, anterior end broader and round; color white to slightly pink or yellow, sometimes with a banded appearance; interior slightly yellow with white margins; beak slightly off-center to the posterior end; distinct Distinguishing concentric ridges and grooves, left valve has wider grooves than right; slight Characteristics ridge on posterior end from beaks to shell margin; right shell has a ridge on the anterior inner dorsal margin from beak to beginning of curve; left shell has a corresponding groove; ridge around anterior muscle scar; pallial line curves slightly upwards between muscle scars; pallial sinus wide. The alternate tellin is more deeply grooved than other tellins, which may have Similar Species minute concentric growth lines. Habitat Gulf and bay, sandy bottoms Maximum Size 7.6 cm (3 in) Previous Scientific Tellina alternata Names

Constricted macoma Page 185 Macoma constricta Family Tellinidae - bivalves

Bivalve (2 shells); shell oval, slightly inflated; color white to brown; anterior end broadly rounded, posterior end angulate, slightly truncate with weak notch on Distinguishing lower margin, slightly bent to the right; beak small, pointed, central; posterior Characteristics end about the same length as anterior end; fine concentric growth rings; weak ridge from beak to posterior end; pallial sinus doubles back on pallial line and nearly touches anterior muscle scar before turning towards posterior scar. The anterior end is shorter, wider and more rounded than most tellins or Similar Species macomas. The posterior end curves to the right, most notable in the right valve. Habitat Bay, sand or muddy bottoms Maximum Size 6.4 cm (2 1/2 in)

Elongate macoma Page 186 Macoma tenta Family Tellinidae - bivalves

Bivalve (2 shells); shell oval, elongate; color white, may be slightly iridescent; anterior end long and rounded; posterior end shorter and truncate, curves to the right; beak closer to posterior end, slightly twisted towards posterior; Distinguishing surface smooth with fine concentric growth lines; slight radial ridge on posterior Characteristics end; anterior abductor scar long and slender; posterior scar more rounded; pallial sinus large, extends almost to anterior scar, meets pallial line about midway; 2 cardinal teeth in right beak, 1 in left beak. More slender than most macomas and tellins. Most similar to the slender Similar Species macoma (M. extenuata) but differs by having a pallial sinus that is rounded above. Habitat Bay, muddy bottoms Maximum Size 1.8 mm (3/4 in) Other Common Names tenta macoma, narrowed macoma

Matagorda macoma Page 187 Macoma mitchilli Family Tellinidae - macomas

Bivalve (2 shells); shell oval, elongate, slightly inflated; color white, iridescent; anterior end broadly rounded; posterior end more narrowly rounded; posterior Distinguishing end slightly shorter than anterior end; beaks small; weak ridge from beak to Characteristics posterior end; shell with faint concentric growth rings; 2 cardinal teeth in right valve, 0-2 in left valve, no lateral teeth; pallial sinus large, rounded dorsally, gently slopes to pallial line before reaching anterior muscle scar. Most similar to the elongate macoma, M. tenta, which has a narrower more Similar Species truncate posterior end. Habitat Bay, near mouths of rivers Maximum Size 2.5 cm (1 in) Other Common Names Mitchell's macoma

Rose-petal tellin Page 188 Eurytellina lineata Family Tellinidae - bivalves

Bivalve (2 shells); shell oval, slightly inflated; color white to pink, darker on beaks; anterior end rounded; posterior end narrower; has fine concentric grooves, smoother on the beaks; slight ridge from beak to ventral margin on Distinguishing posterior end; posterior end curves to the right; pallial sinus long, not reaching Characteristics above abductor muscle scars, reaches close to, nearly touching anterior muscle and then dropping to pallial line; 2 teeth in each beak; right valve with well developed lateral teeth, left valve with anterior lateral tooth. Similar in shape to the Tampa tellin (Angulus tampaensis). The Tampa tellin is Similar Species wider dorsoventrally with a less pointed posterior end. Its pallial sinus does not come as close to the anterior muscle scar as in the rose-petal tellin. Habitat Gulf, reefs and banks Maximum Size 3.8 cm (1 1/2 in)

Short macoma Page 189 Macoma brevifrons Family Tellinidae - bivalves

Bivalve (2 shells); shell oval, dorsal and ventral margins almost parallel, slightly inflated, color white to pale pink, sometimes with brown band on margins; posterior end short, truncated, anterior end longer, broadly rounded; rounded Distinguishing ridge from beak to ventral margin on posterior end; has commarginal growth Characteristics lines and faint radial lines; beaks small, pointed; both shells with 2 teeth under beaks, the hind teeth bifid (split in two); the pallial sinus is long, reaching close to the anterior muscle scar. The short macoma has a noticeably short posterior end. That and its pallial line Similar Species will help distinguish it from other macomas Habitat Bay, sand and muddy bottoms Maximum Size 2.5 cm (1 in)

Tagelus-like macoma Page 190 Macoma tageliformis Family Tellinidae - bivalves

Bivalve (2 shells); shell oblong, oval, slightly inflated, left shell more inflated than right shell; color white to off-white; beak posterior from central; anterior end broadly rounded, posterior end rounded but slightly truncate, narrower than Distinguishing anterior end; fine concentric growth rings; beak points posteriorly; weak ridge Characteristics from beak to posterior end; posterior end curves to the right; anterior muscle scar elongate; pallial sinus doubles back on pallial line before rising and turning toward anterior muscle scar. The tagelus-like macoma is more oblong, and wider and more rounder on both Similar Species ends (but especially the posterior end) than most tellins and macoma. Habitat Gulf, sand to silty clay bottoms Maximum Size 6.4 cm (2 1/2 in)

Veneridae - Venus Clams Page 191

Veneridae, the venus clams, have thick shells that are ovate to elongate, triangular to squarish. The outer shells can be smooth or have concentric or radial ribs or both. They usually have a well developed depression on the anterior dorsal margin (lunule) next to the beak. Venus clams actively burrower in soft sediments. Sometimes they nestle in rock crevices or among marine growths. They are common in intertidal and shallow subtidal sediments. Many, like the northern quahog on the east coast, are edible and support major commercial fisheries. There are 29 species found in Texas waters.

Disk dosinia Page 192 Dosinia discus Family Veneridae - bivalves

Bivalve (2 shells); shells circular in shape, very slightly inflated, strong not Distinguishing fragile; shell color off white; fine concentric ridges on shell; beak prominent, Characteristics pointy, curved and pointing anteriorly; 2 large muscle scars on interior, pallial sinus cone-shaped. Similar to the elegant dosinia, but the elegant dosinia has wide ridges that are Similar Species farther apart and is not as flat as the disk dosinia Habitat Gulf, sand or sandy mud bottoms Maximum Size 7.6 cm (3 in)

Elegant dosinia Page 193 Dosinia elegans Family Veneridae - bivalves

Bivalve (2 shells); shell circular, slightly inflated; color off-white to light yellow; Distinguishing concentric ridges that get wider towards the ventral margin; beak curved Characteristics anteriorly; 3 teeth on each beak, left middle tooth and right posterior tooth bifid (2 lobes), pallial sinus cone-shaped. Similar to the disk dosinia but elegant dosinia has less and wider concentric ribs Similar Species than disk dosinia. Disk dosinia has a more compressed shell. Habitat Gulf, sand or sandy mud bottoms Maximum Size 7.6 cm (3 in)

False angelwing Page 194 Petricolaria pholadiformis Family Veneridae - bivalves

Bivalve (2 shells); shell oval, elongate, inflated, narrow, fragile; color white; beaks low, near the anterior end; radial ridges stronger on anterior end, Distinguishing become weaker on posterior end, anterior ridges scaled; fine concentric growth Characteristics lines; no hard projection (apophysis) under beak (don't mistake the beak's teeth for the projection). True angelwings have a hard, sometimes spoon-shaped projection underneath Similar Species beak. The false angelwing doesn't. Habitat Bay, around the shoreline Maximum Size 5 cm (2 in) Previous Scientific Petrocola pholadiformis Names

Florida cross-barred venus Page 195 Chione elevata Family Veneridae - bivalves

Bivalve (2 shells); shell ovate, somewhat triagonal, moderately inflated; color white to off-white with brown mottling; inside white on the margins, purplish brown in center; anterior margin curved, posterior margin more angulate; beak Distinguishing and upper shell curved toward the anterior; concentric ridges crossed by radial Characteristics ribs, both widely spaced; concentric ridges bladelike when not worn down; sharp ridge from beak to lower posterior edge; depression on posterior dorsal surface (escutcheon) long, smooth; interior margins crenulate (scalloped). The distinctive cross-bar pattern of widely space concentric ridges and radial Similar Species ribs distinguishes this species. Habitat Bay, more abundant in vegetated areas Maximum Size 4.5 cm (1 3/4 in) Previous Scientific Chione cancellata Names

Lady-in-waiting venus Page 196 Puberella intapurpurea Family Veneridae - bivalves

Bivalve (2 shells); shell oval but somewhat triangular, inflated; color off-white with reddish brown blotches; distinct concentric ridges, beaded or ribbed on Distinguishing lower edges giving a cross-hatched look; ridges in non-worn specimens with Characteristics flat, plate-like extensions more prominent at posterior end; interior ventral margin crenulate; slight ridge from beak to posterior margin; pallial sinus small, triangular. Similar to the Florida cross-barred venus whose concentric ridges are much Similar Species farther apart than in the lady-in-waiting venus. Habitat Gulf, sandy or shelly bottoms Maximum Size 3.8 cm (1 1/2 in) Previous Scientific Chione intapurpurea Names

Southern quahog Page 197 Mercenaria campechiensis Family Veneridae - bivalves

Bivalve (2 shells); shell ovate, very inflated, beak angles towards the anterior; color grayish white, sometimes with a brown skin (periostracum), interior white; many thick, concentric ribs that go all the way around the shell (in juveniles the Distinguishing ribs are wide spread with smooth shell between the ribs); edges of the inner Characteristics margin are crenulate; the depression in front of the beaks (the lunule) is as wide as long in large shells; has a small z-shaped pallial sinus; impression behind the beaks (the escutcheon) is well developed with a ridge between the 2 shells. Similar to the Texas quahog, but the Texas quahog concentric ridges are Similar Species weaker, and become smoother towards the center of the shell and its lunule is longer than wide. Habitat Nearshore Gulf, bays, higher salinities Maximum Size 17 cm (6 3/4)

Sunray venus Page 198 Macrocallista nimbosa Family Veneridae - bivalves

Bivalve (2 shells); shell elongate, oval, smooth, slightly inflated; color pale pink Distinguishing or brown with broken brownish radiating bands (occasionally has darker Characteristics concentric bands instead of radiating bands); fine concentric growth lines; beaks anterior to center, point anteriorly; anterior dorsal margin concave. Similar Species Easily distinguished by its color and patterns. Also is the largest venus shell. Habitat Gulf and bay, sandy bottoms Maximum Size 15 cm (6 in) Previous Scientific Callista nibosa Names

Texas quahog Page 199 Mercenaria texana Family Veneridae - bivalves

Bivalve (2 shells); shell ovate, very inflated, beak angles towards the anterior; color grayish white, sometimes with a brown skin (periostracum), interior white; Distinguishing many fine concentric ribs, ribs become smoother in center of shell; the Characteristics depression in front of the beaks (the lunule) is longer than wide in large shells; has a small z-shaped pallial sinus. Similar to the southern quahog, but the southern quahog's concentric ridges Similar Species are strong throughout the shell, and its lunule is as wide as long. Habitat Nearshore Gulf, bays, higher salinities Maximum Size 17 cm (6 3/4) Previous Scientific M. campechiensis texana Names

Texas venus Page 200 Agriopoma texasianum Family Veneridae - bivalves

Bivalve (2 shells); shell oblong, oval, moderately inflated; color white to grayish white; beak spirals anteriorly; posterior end rounded; anterior end more Distinguishing angulate, high; shell smooth with fine concentric growth lines; pallial line with Characteristics triangular sinus, touching the posterior muscle scar; 1st cardinal tooth under beak S-shaped. Other venuses of similar shape appear to be wider, not as elongate. The S- Similar Species shaped cardinal tooth may help distinguish this species. Habitat Gulf and bay, sand and mud bottoms Maximum Size 7.6 cm (3 in) Previous Scientific Callocardia texasiana Names

Page 201

abra, Common Atlantic Caryocorbula caribaea Florida cross-barred venus Abra aequalis Chama macerophylla Florida prickly cockle Acer domingensis Channeled duck clam Fragile surf clam Aequipecten muscosus Chione elevata Geukensia granosissima Agriopoma texasianum cockle, Egg Giant Atlantic cockle Alternate tellin cockle, Florida prickly Green jackknife clam American horse mussel cockle, Giant Atlantic Half-naked pen shell Amygdalum papyrium cockle, Yellow egg hiatella, Arctic Anadara notabilis cockle, Yellow prickly Hiatella arctica Anadara transversa Codakia orbicularis Hooked mussel Anatina anatina Comb bittersweet Incongruous ark Angelwing Common Atlantic abra Ischadium recurvum angelwing, Campeche Common jingle jackknife clam, Green angelwing, False Concentric nut clam jackknife clam, Minor Anodontia alba Constricted macoma jewelbox, Leafy Anomia simplex coquina, Texas jingle, Common Arca imbricata coquina, Variable kitten's paw, Atlantic Arca zebra corbula, Caribbean Lady-in-waiting venus Arctic hiatella Crassostrea virginica Laevicardium mortoni Argopectin gibbus Crested oyster Laevicardium serratum Argopectin irradians Ctenoides mitis Leafy jewelbox amplicostatus Cyrtopleura costata lucine, Buttercup ark, Blood Dallocardia muricata lucine, Thick ark, Eared Dark false mussel lucine, Tiger ark, Incongruous Digitate thorny oyster Lunarca ovalis ark, Mossy Dinocardium robustum Macoma brevifrons ark, Ponderous Disk dosinia Macoma constricta ark, Transverse Donax texasianus Macoma mitchilli ark, Turkey wing Donax variabilis Macoma tageliformis ark, White miniature Dosinia discus Macoma tenta Atlantic calico scallop Dosinia elegans macoma, Constricted Atlantic kitten's paw dosinia, Disk macoma, Elongate Atlantic paper mussel dosinia, Elegant macoma, Matagoda Atlantic pearl oyster duck clam, Channeled macoma, Short Atlantic rangia duck clam, Smooth macoma, Tagelus-like Atrina seminuda Dwarf surf clam Macrocallista nimbosa Atrina serrata Eared ark Mactrotoma fragilis Matagorda macoma bittersweet, Comb Eastern oyster Mercenaria campechiensis Blood ark Egg cockle Mercenaria texana Broad-ribbed carditid Elegant dosinia Minor jackknife clam Brown rangia Elongate macoma Modiolus americanus Buttercup lucine Ensis minor Mossy ark Campeche angelwing Eurytellina alternata Mulina lateralis Carditamera floridana Eurytellina lineata mussel, American horse carditid, Broad-ribbed Euvola papyracea Caribbean corbula mussel, Atlantic paper False angelwing

Page 202

mussel, Dark false Short macoma mussel, Hooked Smooth duck clam mussel, Southern ribbed Smooth flame scallop Mytilopsis leucophaeata Solen viridis Noetia ponderosa Southern quahog Nuculana concentrica Southern ribbed mussel nut clam, Concentric Southern surf clam Ostrea equestris Spisula raveneli oyster, Atlantic pearl Spondylus tenuis oyster, Crested spoonclam, Unequal oyster, Digitate thorny Stout tagelus oyster, Eastern Sunray venus Paper scallop surf clam, Dwarf pen shell, Half-naked surf clam, Fragile pen shell, Rough surf clam, Southern pen shell, Saw-toothed Tagelus plebius Periploma margaritaceum tagelus, Stout Petricolaria pholadiformis Tagelus-like macoma mussel, Dark falsessel, Dark false Phacoides pectinata tellin, Alternate Pholas campechiensis tellin, Rose-petal Pinctada imbricata Texas coquina Pinna rudis Texas quahog Plicatula gibbosa Texas venus Ponderous ark Thick lucine Puberella intapurpurea Tiger lucine quahog, Southern Trachycardium egmontianum quahog, Texas Transverse ark Raeta plicatella Tucetona pectinata rangia, Atlantic Turkey wing rangia, Brown Unequal spoonclam Rangia cuneata Variable coquina Rangia flexuosa venus, Florida cross-barred razor clam, Green jackknife venus, Lady-in-waiting razor clam, Minor jackknife venus, Sunray razor clam, Stout tagulus venus, Texas Rose-petal tellin Western bay scallop Rough pen shell White Atlantic semele Rough scallop White miniature ark Saw-toothed pen shell Yellow egg cockle scallop, Atlantic calico Yellow prickly cockle scallop, Paper scallop, Rough scallop, Smooth flame scallop, Western bay Scapharca brasiliana Semele proficua semele, White Atlantic

Marine Gastropods of Texas Page 203

Cream colored sea slug Mottled sea hare Common sundial Brazilian armina Cerberilla tanna Aplysia fasciata Architectonica nobilis Armina muelleri Family Aeolidiidae Family Aplysiidae Family Architectonicidae Family Arminidae

Cancellate cantharus Common Atlantic slippersnail Eastern white slippersnail Convex slippersnail Solenosteira cancellaria Crepidula fornicata Crepidula depressa Crepidula convexa Family Buccinidae Family Calyptraeidae Family Calyptraeidae Family Calyptraeidae

Reticulated cowrie helmet Well-ribbed dovesnail Fat dovesnail Measled cowrie Cypraecassis testiculus Costoanachis translirata Parvanachis obesa Macrocypraea zebra Family Cassidae Family Columbellidae Family Columbellidae Family Cypraeidae

Eastern melampus Angulate wentletrap Tollin's wentletrap Semismooth wentletrap Melampus bidentatus Epitonium angulatum Epitonium tollini Epitonium apiculatum Family Ellobiidae Family Epitoniidae Family Epitoniidae Family Epitoniidae

Wester dondice True tulip Banded tulip Janthina Dondice occidetalis Fasciolaria tulipa Fasciolaria lilium Janthina janthina Family Facelinidae Family Fasciolariidae Family Fasciolariidae Family Janthinidae

Interrupted periwinkle Marsh periwinkle Shouldered pearwhelk Pearwhelk Echinolittorina interrupta Littoraria irrorata Busycotypus plagosus Busycotypus spiratus Family Littorinidae Family Littorinidae Family Melongenidae Family Melongenidae

Page 204

Splendid whelk Lightning whelk Florida rocksnail Beau's murex Busycon candelabrum Busycon pulleyi Stramonita haemastoma Chicoreus beauii Family Melongenidae Family Melongenidae Family Muricidae Family Muricidae

Giant eastern murex Hays' rocksnail Sharp nassa Bruised nassa Hexaplex fulvescens Stramonita canaliculata Nassarius acutus Nassarius vibex Family Muricidae Family Muricidae Family Nassariidae Family Nassariidae

Miniature moonsnail False shark eye Shark eye White baby ear Tectonatica pusilla Neverita delessertiana Neverita duplicata Sinum perspectivum Family Naticidae Family Naticidae Family Naticidae Family Naticidae

Virgin nerite Four-toothed nerite Lettered olive Sargassum nudibranch Neritina virginea Nerita versicolor Oliva sayana Scyllaea pelagica Family Neritidae Family Neritidae Family Olividae Family Scyllaeidae

Striped false limpet Hawkwing conch Roostertail conch Gray Atlantic auger Siphonaria pectinata Lobatus raninus Aliger gallus Hastula cinerea Family Siphonariidae Family Strombidae Family Strombidae Family Terebridae

Fine-ribbed auger Salle's auger Giant tun Marylee's auger Terebra protexta Hastula salleana Tonna galea Hastula maryleeae Family Terebridae Family Terebridae Family Tonnidae Family Terebridae

Fargo's wormsnail Vermicularia fargoi Family Turritellidae

Page 205

Fargo's wormsnail Vermicularia fargoi Family Turritellidae

Page 206 Terebridae - Auger Shells Page 207

Terebridae, the auger shells, have tall, slender, conical shells with high pointed spires and numerous whorls. The siphonal canals are short, sometimes twisted, with a distinct notch at its base. Most have some sort of axial (radial) ribs. Their common name refers to the shell's resemblance to boring drill bits or screws. They are sand-dwelling carnivores. Many have a venomous barb (similar to cone shells) that is used to stun their prey which consists mainly of worms. The venom from Terebridae (called teretoxins) are similar in structure and composition to the venom from cone shells (called conotoxins, one of with has already been approved as a drug to alleviate chronic pain in HIV and cancer patients) and is currently being studied for therapeutic and pharmacological potentials. There are 7 species found in Texas.

Fine-ribbed auger Page 208 Terebra protexta Family Terebridae - gastropods

Gastropod (1 shell); shell spiral in shape, elongate, high spire; color grayish to brown; radial ribs crossed by fine spiral lines; radial ribs slightly indented just Distinguishing below sutures; whorls slightly convex to nearly straight; radial ribs smooth to Characteristics somewhat knobby; siphonal canal short, twisted to the left; raised ridge on outer columella (part of siphonal canal); notch at base of siphonal canal. Distinguished from most augers by its strong axial (radial) ribs. Most similar to Similar Species the common American auger, T. dislocata, which is slightly larger (to 6.4 cm or 2 1/2 in.) and has deeper, more pronounced indentations below the sutures. Habitat Gulf, sandy bottoms Maximum Size 2.8 cm (1 in)

Gray Atlantic auger Page 209 Hastula cinerea Family Terebridae - gastropods

Gastropod (1 shell); shell spiral in shape, elongate, color grayish brown, thin white band around sutures, wider brownish band with white streaks below that; Distinguishing apex (tip) very pointed; radial ribs starting at sutures terminating almost halfway Characteristics down whorls; many microscopic pits on shell, in spiraling whorls; siphonal canal curved with a point. The Salle's auger and the gray Atlantic auger are very similar, and one may need high magnification to determine the differences. The spiral threads on Salle's auger are more widely spaced than on the gray Atlantic auger, and the spiral ridge at the base of the shell of Salle's is a pronounced, lipped ridge Similar Species whereas the gray Atlantic's is a flattened ridge (see http://z14.invisionfree.com/Conchologist_Forum/ar/t2631.htm). Marylee's auger has 2 rows of axial ribs (most distinct on body whorl) and no microscopic pits. All other augers are knobbed. Habitat Gulf, surf zone, usually buries in the sand Maximum Size 7 cm (2 3/4 in)

Marylee's auger Page 210 Hastula maryleeae Family Terebridae - gastropods

Gastropod (1 shell); shell spiral in shape, elongate, small; color ivory white to brown, white spiraling band on body whorl and at sutures; sutures distinct; apex (tip) very pointed; 2 rows of axial ribs that start below and above sutures, Distinguishing usually joining in the middle, especially distinct on the body whorl; minute Characteristics spirally striations that do not have microscopic pits; aperture narrow, elongate, pointed at top; siphonal canal short, slightly curved at bottom; shallow depression in columella. Marylee's auger is distinct from other auger by having 2 rows of axial ribs (most distinct on the body whorl) per whorl. Other augers only have 1. Marylee's also Similar Species does not have the microscopic pits on the spiral striations that many other augers have. Habitat Gulf, surf zone, usually buries in the sand Maximum Size 2.5 cm (1 in)

Salle's auger Page 211 Hastula salleana Family Terebridae - gastropods

Gastropod (1 shell); shell spiral in shape, elongate, small; color varies from grayish brown to pinkish gray, white band below sutures, brown band below Distinguishing white band, slender white band on body whirl; apex (tip) very pointed; radial Characteristics ribs starting at sutures terminating almost halfway down whorls; many microscopic pits on shell, in spiraling rows; siphonal canal curved with a point. The Salle's auger and the gray Atlantic auger are very similar, and one may need high magnification to determine the differences. The spiral threads on Salle's auger are more widely spaced than on the gray Atlantic auger, and the spiral ridge at the base of the shell of Salle's is a pronounced, lipped ridge Similar Species whereas the gray Atlantic's is a flattened ridge (see http://z14.invisionfree.com/Conchologist_Forum/ar/t2631.htm). Marylee's auger has 2 rows of axial ribs (most distinct on body whorl) and no microscopic pits. All other augers are knobbed. Habitat Gulf, surf zone, usually buries in the sand Maximum Size 4 cm (1 1/2 in)

Strombidae - True Conchs Page 212

Strombidae, the true conchs, have medium to large shells with a conic, pointed spire. The outer lip of the shell flares outward, sometimes upward, and may have spines or knobs on its edge. The sculpture may be smooth or have knob-like projections, usually occurring on the shoulders of the whorls. There is a distinct notch at the lower end of the outer lip from which it can extrude an eye. The aperture is long and narrow. The operculum is small and claw-like and does not enclose the entire aperture. It is used for locomotion and defense. This allows the snail to kick or leap instead of gliding smoothly like other snails. Some of these snails once supported a huge fishery but has since dwindled due to overfishing. There are 5 species found in Texas waters.

Hawkwing conch Page 213 Lobatus raninus Family Strombidae - gastropods

Gastropod (1 shell); shell spiral in shape, spire medium, pointed; color mottling and streaks of brown and white; about 8 whorls; body whorl with strongly knobbed shoulder, largest knob on back with smaller knob between it and Distinguishing margin, other whorls with small, knobs above sutures; aperture thick, flared with Characteristics broad extension on upper end, rarely extends beyond the spire; body whorl with thick, widely spaced, sometimes knobbed ridges; distinct wavy fold ("stromboid notch") on lower outer lip of aperture, narrow folds on inner surface; siphonal canal short, extends backwards. Similar to the roostertail conch, Aliger gallus, but the hawkwing conch's upper Similar Species extension is wider and shorter. Habitat Gulf, on offshore reefs Maximum Size 12 cm (5 in) Previous Scientific Tricornis raninus, Strombus raninus Names

Roostertail conch Page 214 Aliger gallus Family Strombidae - gastropods

Gastropod (1 shell); shell spiral in shape, spire medium tall, pointed; color mottled brown, yellow and white; aperture lip with narrow extension extending Distinguishing above spire; about 7 whorls, knobbed above sutures, body whorl with large Characteristics triangular knobs on shoulders; body whirl with spiraling ridges; outer lip of aperture flared, curved backwards with undulating short, broad fold ("stromboid notch") at base; siphonal canal narrow, extends backwards. Similar Species No other conch has the narrow extension above the whorls. Habitat Gulf, offshore, found at the Florida Garden Banks Maximum Size 20 cm (8 in) Previous Scientific Stombus gallus Names Comments Rare

Cypraeidae - Cowries Page 215

Cypraeidae, the cowries, have oval, well-inflated shells that are smooth, often brightly colored, with a narrow, toothed aperture that runs the entire length of the shell and is slightly set off to the right. The spire is basically nonexistent. The aperture has no operculum (plate that closes the aperture). The shell stays shiny because the snail covers the shell with its mantle which continually deposits a coat of enamel and protects the shell from wear and tear. Juvenile cowries are distinctly different from adults. Their aperture is wider and the outer lip is thin. When the cowrie becomes an adult, its outer lip thickens and curves inward. Cowries can mature at different sizes depending on factors such as temperature and food sources. Those that mature at smaller sizes are called dwarf shells. Cowries are nocturnal and feed on algae. There are 4 species found in Texas waters.

Measled cowrie Page 216 Macrocypraea zebra Family Cypraeidae - gastropods

Gastropod (1 shell), shell spiral in shape, elongate, almost oval shape, shiny, with no spire; shell brownish with whitish, sometimes ocellated (darker in Distinguishing center) spots, sometimes with wide brown bands; 1 whorl; aperture elongate, Characteristics narrow, notched on both ends, beige-colored with numerous brown striations (teeth) along inner and outer lips; some ocellated spots on lateral sides. Similar to the Atlantic deer cowrie, M. cervus, but the deer cowrie does not Similar Species have ocellated spots on the lateral margin and is more inflated than the measled cowrie. Habitat Gulf, on offshore reefs Maximum Size 11.5 cm (4 1/2 in) Previous Scientific Cypraea zebra, C.exanthema Names

Columbellidae - Dovesnails Page 217

Columbellidae, the dovesnails, have shells that vary in shape, some being short and ovate, others being elongate. Most are < 2.5 cm (1 in) in length. One constant feature of this family is the spiraling ribs on the lower portion of the shell. Most live on hard substrates and algae flats, but some crawl upon soft sand. They feed on both plant and animal matter. There are 13 species found in Texas.

Fat dovesnail Page 218 Parvanachis obesa Family Columbellidae - gastropods

Gastropod (1 shell); shell spiral, spire about 1/2 height of shell; color whitish to brownish with brown spiraling bands; short axial ribs between sutures, beaded just below sutures; base of shell without axial ribs; spiral ribs in between axial Distinguishing ribs, but not crossing axial ribs; spiral ribs unbroken on base area; aperture Characteristics almost 1/2 height of shell; outer lip of aperture thickened (in adults), inside of lip dentate (small rounded tooth-like projections); siphonal canal short, shallow notch at base; extremely small snail. The short axial ribs with spiral ribs in between, but not crossing axial ribs, help Similar Species distinguish this shell. Other dovesnails, if they have axial ribs, have spiral ribs that cross the axial ribs. Habitat Gulf, sand bottoms Maximum Size 0.8 cm (1/3 in)

Well-ribbed dovesnail Page 219 Costoanachis translirata Family Columbellidae - gastropods

Gastropod (1 shell); shell spiral, elongate, narrow; color yellowish to brown with white blotches or a white band below the sutures; has axial ribs crossed by spiral ribs giving a beaded appearance, beads at sutures sometimes enlarged Distinguishing giving a shouldered appearance (in some specimens the spiral ribs are finer, Characteristics less noticeable); spire high, more than 1/2 length of shell; whorls not inflated, almost a straight outline from whorl to whorl; outer lip of aperture thickened, inner side of outer lip crenulate (scalloped); siphonal canal short, moderately wide, < 1/2 length of shell, shallow notch at base. The well-ribbed dovesnail is narrower than most other dovesnails. Its beaded Similar Species appearance and nearly smooth transaction between whorls also help distinguish it from others. Habitat Gulf, soft bottoms Maximum Size 2.3 cm (1 in) Previous Scientific Anarchis lafresnayi Names

Ellobiidae - Ellobids Page 220

Shells in the Ellobiidae family take a variety of forms. They may be short and ovate to elongate and conic, with a low or high spire. The shells usually have several folds or "teeth" projecting from the inner margin of the aperture. The organisms are land snails and air breathers that live in saline environments, above the high tide line, such as mangrove swamps and salt marshes. They feed on algae and other plant life. There are about 300 species world-wide and there is no collective name for them, though in Singapore they are called belongkeng. Only 2 species are found in Texas.

Eastern melampus Page 221 Melampus bidentatus Family Ellobiidae - gastropods

Gastropod (1 shell); shell spiral in shape, oval, smooth, whorls flat on sides; color light brown with darker brown spiral bands; spire short, pointed; body Distinguishing whorl takes up most of length; aperture long and narrow; inside margin of outer Characteristics lip finely toothed; inner margin of aperture may have 2 or 3 folds; siphonal canal extremely short, almost nonexistent. Similar Species This is the only melampus in the area with that color pattern. Habitat Bay, found attached to marsh grasses Maximum Size 2 cm (3/4 in) Other Common Names coffee bean snail, salt marsh snail, coffee melampus Comments Air breather.

Siphonariidae - False limpets Page 222

Siphonariidae, the false limpets, have ovate, conic, open shells. The organism lives underneath the shell and uses its muscular foot to attach to hard substrates. False limpets, although resembling true limpets, are air breathers and do not possess true gills. They live in semi-aquatic environments, such as the intertidal zone along jetties. The empty shell can be distinguished from true limpets by having a groove on the right side of the underside which transects the ring of muscle attachment scars. Their primary prey is microscopic plant life. There are 2 species found in Texas.

Striped false limpet Page 223 Siphonaria pectinata Family Siphonariidae - gastropods

Gastropod (1 shell); shell peak shaped, no hole at top; shell color dark and light radiating lines on upper surface and outer half underside of shell; radiating Distinguishing ridges; underside is glossy; mouth oval; apex of shell slightly off-center; muscle Characteristics scar C-shaped around underside of shell, ends slightly larger, thin groove interrupts scar on posterior end. Similar to true limpets, but true limpets in the area have a hole at the apex of Similar Species the shell. Habitat Gulf, common on rocks and jetties Maximum Size 3 cm (1 1/5 in), usually less than 1/2 that size. Comments Not a true limpet. This organism is an air breather.

Cassidae - Helmet and Bonnet Snails Page 224

Cassidae, the helmet snails (also called bonnet snails), have medium to large shells with a large body whorl, small spire and a thickened, reflected outer aperture lip. The inner and outer lips are usually toothed. The siphonal canal is generally short, narrow and twisted. Many can be found in the intertidal zone where they bury in the sand during the day and come out at night. Others prefer harder substrates or deeper water. Their favorite prey are echinoderms, especially sea urchins. The snails sneaks up on their prey, raise up high and drop their heavy shells onto the urchin. The thick skin of the snail's foot provides protection from the urchin's spines. The snail will release a paralytic enzyme that protects the snail from toxins in the urchin's spines. It then drills a hole in the urchins with a raspy tongue (called radula) aided by a secretion high in sulfuric acid and proceeds to suck out the soft parts.

Many of the shells in this family are large and beautiful. Because of their thick shell, some are used by artisans for carving cameos. There are 6 species found in Texas waters.

Reticulated cowrie helmet Page 225 Cypraecassis testiculus Family Cassidae - gastropods

Gastropod (1 shell), shell spiral in shape, ovate, tapering towards the bottom, short spire, body whorl takes up most of shell; color background orangish brown to gray to pink, brown spots or blotches in spiraling rows with lighter color in between blotches; radiating ribs crossed by widely space, shallow Distinguishing spiraling grooves; aperture side smooth, lighter colored, an orangish band Characteristics about 2/3's down and orange spot on shoulder; aperture long, narrow, outer lip of aperture thickened, toothed on inside, dark nearly black spots on back side of lip; columella (inner side of aperture) crenulate (ridged); siphonal canal short, angled back and upturned. This helmet has a distinctive color pattern which helps distinguish it from other Similar Species helmets. Habitat Gulf, reef areas Maximum Size 7.6 cm (3 in)

Naticidae - Moon Snails Page 226

Naticidae, the moon snails, usually have smooth, inflated shells with medium to low spires. The body whorl takes up most of its height and the shell aperture is usually large. These mollusks usually prey on other mollusks by wrapping their large foot around the prey and secreting an acid which helps its tongue (radula) drill a hole into the shell. Then the tissue of the prey is sucked out. Moon snails live in sandy, muddy areas, both inshore and offshore. There are 9 species found in Texas.

False shark eye Page 227 Neverita delessertiana Family Naticidae - gastropods

Gastropod (1 shell); shell spiral in shape, smooth, short and wide, body whorl makes up most of shell; color greenish gray to light brown, sometimes with orangish brown markings, base of shell usually white; spire low, almost non- Distinguishing existent (bay specimens with higher spire than gulf specimens), last two whorls Characteristics form pointy tip; siphonal canal absent; bottom of shell with thick brown to purple callus; sunken depression (the umbilicus) with a spiraling ridge at edge of wall; aperture large, oval. Very similar to the shark eye, N. duplicata, but the umbilicus (depression at Similar Species bottom of shell) has a ridge on the edge of its wall (smooth and rounded in N. duplicata). Habitat Bay mostly Maximum Size 7.6 cm (3 in) Previous Scientific Polinices duplicatus Names

Miniature moonsnail Page 228 Tectonatica pusilla Family Naticidae - gastropods

Gastropod (1 shell), shell spiral in shape, ovate; body whorl large; somewhat raised spire; color white to yellowish gray, usually with a lighter band below sutures, with brownish zigzag markings on body whorl; interior whitish, Distinguishing sometimes with brown markings; shell smooth (shiny when fresh) with fine axial Characteristics growth lines; aperture D-shaped, columella (center pillar) oblique (slanted); callus (raised harden part) covering most of umbilicus (sunken or depressed area at the base of the shell) leaving only a small slit opening; callus not darkened. Most similar to the shark eyes (Neverita duplicata and N. delessertiana), both Similar Species of which have flatter spires than the miniature moonsnail. Habitat Gulf and bay, sandy bottoms Maximum Size 0.8 cm (1/3 in)

Shark eye Page 229 Neverita duplicata Family Naticidae - gastropods

Gastropod (1 shell); shell spiral in shape, smooth, short and wide, body whorl makes up most of shell; color greenish gray to light brown, sometimes with Distinguishing orangish brown markings, base of shell usually white; spire low but pointed, Characteristics siphonal canal absent; bottom of shell with thick brown to purple callus; sunken depression (the umbilicus) smooth (no spiral ridge) at the edge of wall; aperture large, oval. Very similar to the false shark eye, N. delessertiana, but the umbilicus Similar Species (depression at bottom of shell) is smooth and rounded on the edge of its wall (ridged in N. delessertiana). Habitat Gulf and bay Maximum Size 7.6 cm (3 in) Other Common Names Atlantic moon snail Previous Scientific Polinices duplicatus Names

White baby ear Page 230 Sinum perspectivum Family Naticidae - gastropods

Gastropod (1 shell); shell spiral in shape, oval, very flat from top to bottom; color white, sometimes with a yellowish outer membrane (periostracum); interior Distinguishing white, polished; spire nearly flat, at level of body whorl; outer shell with fine, Characteristics spiraling growth lines; aperture wide, round, outer lip slightly flared; no siphonal canal; central pillar (columella) short, curve; when live, animal completely envelops shell. Similar to the brown baby ear which has a browner color, a higher spire, and Similar Species the outer lip of the aperture is not flared. Habitat Gulf and bay, sandy bottoms Maximum Size 5 cm (2 in) Other Common Names common baby's ear

Muricidae - Murex and Rocksnails Page 231

Muricidae, the murex and rocksnails, come in a variety of shapes. The more interesting ones have spiraling ridges, axial varices and/or spines. Others are less ornately sculptured and may be smooth, nodulose or with small spines. They are carnivorous and feed on other invertebrates, including other mollusks. Some bore into their prey's shell using their rasp-like tongue (radula) and then secrete neurotoxin to paralyze its prey. Others like to chip away at the edges of shells until the prey is exposed. Most live on rocky shores or substrates and coral reefs. There are 26 species found in Texas.

Beau's murex Page 232 Chicoreus beauii Family Muricidae - gastropods

Gastropod (1 shell); shell spiral in shape, varices - 3 radial rows made of long spines with raised webbing in between, spines made from folding shell, spines may be worn or broken; low knobs between the varices; up to 9 distinct whorls; Distinguishing spiraling ridges on whorls; shell color cream to pale brown; aperture (opening) Characteristics oval, outer margins smooth or slightly scalloped; inside aperture white; spire high, sutures between whorls distinct; siphonal canal long, may be bent or straight, sometimes siphonal canal is split into 2 canals, only 1 of which opens up to aperture. Similar Species The webbed varices are unique to this species. Habitat Gulf, deep waters Maximum Size 13 cm (5 in) Previous Scientific Siratus beauii, Murex beauii Names

Florida rocksnail Page 233 Stramonita haemastoma Family Muricidae - gastropods

Gastropod (1 shell); shell spiral in shape; fine spiral lines; color gray to tan, mottle with dark brown, grayish or orange marks; no double rows of strong Distinguishing nodules on shoulder of body whorl, may be small nodules on upper whorls; Characteristics inside aperture orange, smooth, grooves on lip; aperture lip usually rounded with no angle; spire medium long; siphonal canal short. Hay's rocksnail has double row of strong nodules on shoulders of whorls, Similar Species aperture lip has a point or angle. Habitat Bay, on hard substrates such as rocks and oyster reefs Maximum Size 8 cm (3 1/5 in) Other Common Names oyster drill Previous Scientific Thais haemastoma Names

Giant eastern murex Page 234 Hexaplex fulvescens Family Muricidae - gastropods

Gastropod (1 shell); shell spiral in shape, many straight spines in 6-10 radial rows (rows are called varices), spines made from folding shell, sometime with 2 tips (bifurcate); spines may be worn or broken; 6-8 indistinct whorls; spiraling Distinguishing ridges on whorls; shell color dirty white to gray, (tan to brown if periostracum is Characteristics intact); aperture oval, outer margins crenulate (scalloped); inside aperture mainly white with some blotching; spire short; siphonal canal short, in older specimens may be completely enclosed, open only at the tip. Other murexes have less rows of spines, usually the siphon canal and spire are Similar Species more elongate. Habitat Gulf, shallow waters Maximum Size 18.5 cm (7 1/4 in) Previous Scientific Murex fulvescens Names

Hays' rocksnail Page 235 Stramonita canaliculata Family Muricidae - gastropods

Gastropod (1 shell); shell spiral in shape; fine spiral lines; color gray to tan, mottle with dark brown, grayish or orange marks; double rows of strong Distinguishing nodules on shoulder of body whorl; inside aperture orange, smooth, numerous Characteristics grooves on lip; upper aperture lip concave, comes to an angle, sometimes has 2 angles, then continues downward; spire medium long; siphonal canal short, usually angled backwards. Florida rocksnail does not have double row of strong nodules (but may have Similar Species weak ones) on whorls and its aperture opening is usually rounded, not angular. Habitat Gulf and passes; hard substrates such as jetties and rocky shores Maximum Size 11.4 cm (4 1/2 in) Other Common Names oyster drill Previous Scientific Thais heamastoma canaliculata Names

Nassariidae - Nassa Mud Snails Page 236

Nassariidae are the nassa mud snails (commonly called dog whelks overseas). Their shells typically have well-developed spires with a short or no siphonal canal and a siphonal notch that is flexed slightly backward. Many have spiral and axial ribs. They are very small, usually less than 2 cm (3/4 in). They are usually found in shallow waters with muddy or sandy substrates. Their diet consists mainly of carrion and they have an elongate feeding apparatus (proboscis) to reach into cracks and crevices. There are 4 species found in Texas.

Bruised nassa Page 237 Nassarius vibex Family Nassariidae - gastropods

Gastropod (1 shell); shell spiral in shape, short, spire extended, pointed; color whitish with spiraling brown bands; spiraling ribs crossed by radial ribs giving a Distinguishing nodular appearance; inner lip of aperture flared, smooth; outer lip thickened, Characteristics smooth above, crenulate (scalloped) towards the bottom; siphon small to absent. Similar to the common eastern nassa, which has a wider aperture and the outer Similar Species lip is more crenulate. Habitat Gulf and bay, sandy bottoms Maximum Size 2 cm (3/4 in)

Sharp nassa Page 238 Nassarius acutus Family Nassariidae - gastropods

Gastropod (1 shell); shell spiral in shape, slender, elongate; color off-white to Distinguishing yellow with thin brown spiraling lines, orangish brown on spire; very knobby, Characteristics elongated beads at spiral and radial intersections; spire long, pointed; spire over 1/2 length of the shell; aperture oval; siphonal canal extremely short. Similar Species Narrower than other area nassas, with spire over 1/2 length of shell. Habitat Gulf, sandy bottoms Maximum Size 1.5 cm (3/5 in)

Neritidae - Nerites Page 239

Neritidae, the nerites, are a family of small snails that may live in fresh, brackish and marine waters. Their shells are nearly tear-drop shaped, thick and often have beautiful and attractive color patterns. Their diet is mainly algae which they scrape off surfaces of plants and other objects. They are usually found clinging to rocks or marsh grasses in the high tide zones. There are 5 species found in Texas.

Four-toothed nerite Page 240 Nerita versicolor Family Neritidae - gastropods

Gastropod (1 shell), shell spiral in shape, short spire, wider than tall; color white with zig zag black and pink bars (variable); thick spiraling ribs; columella (inner Distinguishing part of aperture) with 4 (occasionally 5) teeth, inner teeth larger and wider than Characteristics outer teeth; inner part of outer lip with small, tooth-like denticles, end ones slightly larger than others. Similar Species This is the only nerite with 4 teeth on inner lip of the aperture. Habitat Gulf, along rocky shores Maximum Size 2.5 cm (1 in)

Virgin nerite Page 241 Neritina virginea Family Neritidae - gastropods

Gastropod (1 shell); shell spiral in shape, small, globose, smooth; color varies widely from olive and brown to red, black and purple, usually with black or white Distinguishing wavy lines or spots, pattern varies; body whorl large, takes up most of shell; Characteristics spire low; aperture half-moon shaped; no siphonal canal; area next to aperture (parietal shelf) inflated, yellowish to white; 8-10 small teeth on inner edge of aperture (columella); operculum black with small, pointed hook at one end. Other nerites in our area are greenish with no markings (emerald nerite) or Similar Species have spiraling ribs (Antillean and four-toothed nerites). The olive nerite is brownish-green to brownish yellow with minute axial dark striations. Habitat Bay margins and grass flats Maximum Size 1.2 cm (1/2 in)

Page 242 Arminidae, Scyllaeidae, Facelinidae and Aeolidiidae - Nudibranchs

Nudibranchs are marine, shell-less gastropod mollusks, in other words, shell-less marine snails. They are born with a shell but shed it after their larval stage. They are soft bodied, and unlike the shelled gastropods with twisted bodies, nudibranchs have bilateral symmetry. Nudibranchs have bushy gill-like plumes on their back near their tail or fleshy outgrowths called cerata on their back and sides that are used for respiration. They also have a pair of fleshy "horns", called rhinophores, on their head that are scent and taste receptors. The cerata are sometimes used for defense or attack. Nudibranchs eat many organisms, such as anemones and hydroids, that have stinging cells called nematocysts. The nematocysts pass through the digestive system and concentrate in the body walls and on the tips of the cerata allowing nudibranchs to use the nematocysts themselves to paralyze its predator or prey.

Nudibranchs are hermaphroditic, having both male and female sex organs in the same body. However, they rarely fertilize themselves and usually will lay their eggs in a gelatinous spiral. Sometimes when two different species meet, a fight ensues and ends with one of them eating the other.

The term "sea slug" is often applied to nudibranchs, but not all sea slugs are nudibranchs. Nudibranch means "naked gills", and their external respiratory appendages distinguish them from other sea slugs.

Most nudibranchs and other sea slugs have beautiful vivid colors. The colors and patterns are used to camouflage themselves or to warn predators that they are poisonous. Highly contrasting pigments are usually a visual warning to predators to be wary of and avoid inedible flesh. Brazilian armina Page 243 Armina muelleri Family Arminidae - gastropods

Gastropod, no shell, body oval-shaped, smooth, flattened; soft, no external skeleton; color reddish brown to black, sometimes with lighter areas centrally and on the ends, white or yellow disconnected sometimes squiggly lines from end to end; mantle and foot lined in white; brownish longitudinal folds Distinguishing (hyponotal lamellae) on the margins of the underside of the mantle are Characteristics digestive glands; in front of the hyponotal lamellae are rows of transverse folds (branchial lamellae), these are the gills; a pair of scent or taste receptors (fleshy tabs called rhinophores) on head, black with white tips, may be withdrawn into a pocket beneath the skin. Similar Species This is the only nudibranch with stripes in the area. Habitat Gulf, sandy bottoms Maximum Size 6 cm (2 1/3 in) Other Common Names sea slug The names Armina abbotti and Armina tigrina (in the U.S.) refer to this species. Comments Preys on sea pansies.

Page 244 Cream colored sea slug Cerberilla tanna Family Aeolidiidae - nudibranchs

Gastropod, no shell, body elongate, soft and flexible, oval shaped; color light brown to pale cream color; head with 2 pair of tentacles, the posterior pair (called rhinophores) on top of the head are very short, smooth, extend upward, the anterior pair (the oral tentacles) are long, about 1/3 the length of the body, Distinguishing extend more sideways, both pairs whitish with a tinge of light blue color; Characteristics sometimes with yellow to orangish spot on head; finger-like outgrowths (called cerata) cover the body, base is pale yellow to orange, most but not all with a dark spot on the outer surface, tips whitish to bluish white; foot with anterior pointed extensions called foot corners, edges of foot bluish. This is the only member of this genus found in the Gulf of Mexico. A bluer, Similar Species more elongate specimen of this genus has been collected in the Caribbean and off Brazil. Habitat Gulf and bay, inhabits sandy areas Maximum Size 2.5 cm (1 in) This specimen was caught in the Gulf of Mexico off Sabine TX. Many thanks to Comments TPWD biologist Terry Stelley for the photographs.

Sargassum nudibranch Page 245 Scyllaea pelagica Family Scyllaeidae - gastropods

Gastropod, no shell; body globular, soft, dorsoventrally flattened; color orangish brown with white specks, sometimes with blue spots; 2 pair of anterior/posterior Distinguishing lobes with branching gills on the tips; head with 2 flat extensions (sensory Characteristics receptors called rhinophores); posterior end has a flattened dorsal flap which stands vertically; small tubercles on body; genital opening on right side in front of anterior lobe; anus between 2 right lobes. The sargassum nudibranch has a unique shape and color that distinguishes it Similar Species from other nudibranchs in the Gulf of Mexico. Habitat Gulf, lives in floating sargassum seaweed Maximum Size 4.5 cm (1 3/4 in)

Western dondice Page 246 Dondice occidentalis Family Facelinidae - gastropods

Gastropod, no shell, body elongate, soft and flexible, translucent; head with 2 pair of tentacles, the posterior pair, called rhinophores are annulated (ringed) with up to 18 rings each; color is extremely variable; head with a median stripe from tip to just behind rhinophores, color varies from yellow to orange to red; Distinguishing body with a broken median stripe down back, color varies from white to bluish Characteristics white to yellow, sometimes absent; sides with broken bands, ranging in color from red to yellow to white, sometimes absent; cerata (outgrowths on the sides) clumped in about 6 groups per side, red to orange bands near tips, tips white to bluish white; sometimes you can see its black jaws showing through the body wall of the head, sometimes distinct, sometimes not. The western dondice can be distinguished from other nudibranchs by its annulated rhinophores, the median stripe on the head and broken body stripe Similar Species on the dorsum, the cerata occurring in groups, and the colored rings near the tips of the cerata. Habitat Gulf and bays, free-swimming, may be associated with (i.e. feeds on) hydroids Maximum Size 3 cm (1 1/5 in) Other Common Names fringe-back nudibranch

Olividae - Olive Snails Page 247

Olividae, the olive snails, have elongated, smooth, shiny shells with a low spire and elongated aperture. Their columella (the central pillars around which the whorls form) usually have several folds. They have no siphonal canal but do have a well-developed siphonal notch. One genus, Oliva, found in Texas, has no operculum. Olives can extend their mantle and foot to cover the entire shell, thus maintaining the shell's shiny finish. They are common in shallow waters on sandy bottoms in which they burrow. Their diet consists of small invertebrates and carrion. There are 2 species found in Texas.

Lettered olive Page 248 Oliva sayana Family Olividae - gastropods

Gastropod (1 shell); shell spiral in shape, smooth, glossy when live, elongate, much taller than wide, body whorl makes up most of shell; shell color light Distinguishing brownish, lighter mottling, 2 broad spiraling bands of darker zigzag pattern; Characteristics spire short, pointed, straight on the sides, channeled between whorls; aperture long and narrow, purplish on the inside, narrow notch at base, no operculum; inner lip of aperture (columellar lip) with several diagonal folds. The Caribbean olive is similar but has different patterns and the body whorl is Similar Species beaded at the top edge. Habitat Gulf and bay (inlets), sandy bottoms Maximum Size 7.5 cm (3 in)

Littorinidae - Periwinkles Page 249

Littorinidae, the "periwinkles" or "winkles" consist of about 180 species worldwide. They usually can be found on rocky shores or jetties in the intertidal zone. Some are found in the quiet waters of mangrove habitats where they live on the trunks or leaves of the mangrove tree. They feed on microscopic algae and other plants. Although they are air breathers, they depend on the water to lay and disperse their eggs which develop into free swimming larvae. There are about 5 species in Texas. They are considered a delicacy in Asian communities but are generally thought to be too small to eat.

Interrupted periwinkle Page 250 Echinolittorina interrupta Family Littorinidae - gastropods

Gastropod (1 shell); shell spiral in shape; longer than wide; spire extended, pointed; background color light with darker brown or black zigzag oblique lines Distinguishing (a variation is with a dark background and white blotches spiraling on body Characteristics whorl); 6-8 whorls; body whorl more than 1/2 shell height; spiral ribs on whorls; outer lip of aperture smooth, not flared; columella smooth, wide, purple to dark brown in color. Similar Species The dark background with the zigzag stripes distinguish this periwinkle. Habitat Gulf, on jetties Maximum Size 2.5 cm (1 in) Other Common Names zebra periwinkle Previous Scientific Littorina ziczac, L. lineolata Names

Marsh periwinkle Page 251 Littoraria irrorata Family Littorinidae - gastropods

Gastropod (1 shell); shell spiral in shape, conical, longer than wide; color grayish white to yellow (may be greenish due to algae), light streaks of purple Distinguishing or reddish brown; spiraling ridges; 8-10 flat-sided whorls; sutures between Characteristics whorls hard to discern; spire pointed; aperture oval with grooves inside outer lip. Other area periwinkles have more distinct color patterns. The cloudy periwinkle Similar Species has rounded whorls and is usually found on harder substrates. Habitat Bay, found attached to marsh grasses or harder substrates above the tide line Maximum Size 3 cm (1 1/5 in) Comments Air breather.

Janthinidae - Purple Sea Snails Page 252

Janthinidae, the purple sea snails, have smooth, globose fragile shells that are usually blue to purple in color. Their foot produces a mucus float, made of several enclosed bubbles of air, outside their shell which allows them to float on the surface of the water. They form communities with other floating organisms, such as the Portuguese man o' war and the by-the-wind sailors, upon which they feed. There are 5 species in Texas waters.

Janthina Page 253 Janthina janthina Family Janthinidae - gastropods

Gastropod (1 shell); shell spiral in shape, smooth with fine, oblique axial lines, fragile, wider than tall; color deep blue to purple on bottom, lighter blue on top, darker at whorl junction, sometimes with a lighter stripe at the very base; body Distinguishing whorl large, wide, angular; spire short; aperture large, wide, bottom edge is Characteristics horizontal, edge of inner lip of (part of the columella) is almost vertical, no operculum, curved backwards; no siphonal canal; when live, will be attached to a bubble raft at the aperture. Other snails in this family are more inflated (globose) than the common Similar Species janthina. Habitat Gulf, floats upside down on the surface of the water using bubble rafts Maximum Size 4 cm (1 1/2 in) width Other Common Names common purple sea snail Comments More common in the spring.

Aplysiidae - Sea Hares Page 254

Aplysiidae, the sea hares, are a family of large sea slugs (marine gastropod mollusks) lacking outer shells. Most have an internal shell that is small and very flimsy. It lies within the sea hare's mantle, which is a flap on the back that covers the gills and other internal organisms. Sea hares have wing-like extensions called parapodia on their sides that allows them to swim or glide through the water. These creatures are herbivores and feed on algae and other sea plants. The color of the sea hare's flesh is derived from pigments in the plants they eat. Some species squirt purple or red ink when disturbed or attacked to confuse predators. Sea hares do not produce the ink. It is extracted from the algae in their diet.

Sea hares are hermaphroditic and have both male and female reproductive organs in their body. When they mate, they can be either male or female. They commonly form lines or chains when mating where the 1st animal acts as a female, the last acts as a male, and the animals inbetween act as both male and female.

Because of their relatively simple, large and easily accessible nervous system, sea hares are used extensively for neurobiological studies, especially in the areas of learning and memory.

Mottled sea hare Page 255 Aplysia fasciata Family Aplysiidae - gastropods

Gastropod, no outer shell; body globular, soft, bulky; color varies from light brown to dark red-brown or red-purple, lighter color mottling on head, neck and wings; head with 2 rounded oral tentacles; smaller rhinophores (tentacle-like sensory receptors) behind oral tentacles on neck; eyes in front of rhinophores, Distinguishing tiny, dark; wing-like flaps (called parapodia) on sides of body, attaching behind Characteristics rhinophores and joined posteriorly; tail is short and rounded; has a flap (the mantle) on its back that covers its gills and internal organs; inside the mantle is a very thin, delicate internal shell that is narrow or wide, concave, light amber color, slightly hooked at apex; also inside the mantle is the ink gland, secretes purple ink. Coloration and shape of the internal shell help distinguish different sea hares. This specimen, found beached, had lost most of its color but showed signs of mottling along the parapodia. The true sooty sea hare, A. morio, is uniformly Similar Species dark brown to black. There is also a spotted sea hare, A. dactylomela, with spots and a ragged sea hare, Bursatella leachii, with soft extensions on its body. Habitat Gulf and bays, shallow, calm waters, wherever there is an abundance of algae Maximum Size 27 cm (10 1/2 in) Other Common Names sooty sea hare Previous Scientific A. willcoxi, A. brasiliana Names

Calyptraeidae - Slippersnails Page 256

Calyptraeidae, the slippersnails, have flattened, sometimes coiled shells with either a small spire or no spire. Their shells lack operculums (the hard plate at the opening of the apertures. These mollusks live inside a "shelf" on the underside of the shell and extend their foot out to attach to hard surfaces. They are mostly sedentary but are able to slowly creep along a surface. Their diet consists of small plankton which are filtered from the water. They may also be referred to as "slipper limpets" due to the resemblance of some shells to a limpet. There are 6 species reported from Texas.

Common Atlantic slippersnail Page 257 Crepidula fornicata Family Calyptraeidae - gastropods

Gastropod (1 shell); shell oval, moderately convex, smooth; apex blunt, curled to the right, forms margin of shell; color alternating white and brown irregular Distinguishing rays (sometimes faded), usually with a white streak down the middle; interior Characteristics tan to purple or brown, smooth; concave shelf or deck (septum) white with a brown ring around it, free margin slightly wavy, takes up about 1/2 the shell, left side slightly longer than right; aperture oval, no operculum. Other area slippersnails have pointed straight apexes and are flat (eastern Similar Species white slippersnail) or the septum takes up less than 1/2 of shell (convex slippersnail). Gulf and bay, attached to hard substrates, commonly found piled up on each Habitat other Maximum Size 5 cm (2 in) Other Common Names common Atlantic slipper shell

Convex slippersnail Page 258 Crepidula convexa Family Calyptraeidae - gastropods

Gastropod (1 shell); shell convex, oval with narrow pointed apex; color tan to purple with brownish lines or spots on shell; shelf or deck (septum) on Distinguishing underside flat or slightly convex, takes up less than 1/2 length of shell, slightly Characteristics longer on the left side, right side almost straight; oval muscle scar just anterior to shelf on right side; apex extends slightly, usually points posteriorly and is excavated underneath. Similar Species Similar slippersnails have decks that cover 1/2 or more the length of the shell. Habitat Gulf and bay, attach to hard substrates Maximum Size 1.2 cm (1/2 in)

Eastern white slippersnail Page 259 Crepidula depressa Family Calyptraeidae - gastropods

Gastropod (1 shell); shell oval, nearly flat, smooth with fine concentric growth Distinguishing lines, thin; small pointed apex on posterior end; color whitish to yellowish; shelf Characteristics or deck (septum) on underside slightly convex, covers about 1/2 of shell, notched on one side. The convex slippersnail's shelf covers less than 1/2 of shell (covers about Similar Species 1/2 in eastern white slippersnail). The common Atlantic slippersnail is much more convex (inflated) than the eastern white slippersnail. Habitat Gulf and bay, attaches to hard substrates Maximum Size 3.7 cm (1 1/2 in)

Architectonicidae - Sundials Page 260

Architectonicidae, the sundials, have wide, low, conic-shaped shells, usually with a small aperture opening to the side. The shells usually have spirally grooves or ridges, granulations or both. Their umbilicus, the depression underneath the shell, is usually wide and goes deep within the shell. Sundials bury into the substrate, usually in subtidal areas, and come out only at night to feed or spawn. They are sometimes found under rocks and corals. Their primary diet is anemones and other related organisms (jellyfishes, corals, etc.). There are 3 species found in Texas.

Common sundial Page 261 Architectonica nobilis Family Architectonicidae - gastropods

Gastropod (1 shell); shell spiral in shape, short, much wider than tall, nearly flat on the bottom; color tan with darker brown spots on spires; has spiraling Distinguishing grooves with a somewhat beaded appearance on upper whorls, beading more Characteristics prominent on base than above; spire short; aperture wider than tall; no siphonal canal; bottom of base with deep opening (umbilicus). Similar Species The beaded sundial has a similar shape but is beaded all over. Habitat Gulf, sandy bottoms Maximum Size 5.1 cm (2 in)

Fasciolariidae - Tulip and Spindle Snails Page 262

Fasciolariidae, the tulip and spindle snails, typically have shells with high spires and long siphonal canals. The shells may be smooth, have spiral ribs, axial folds or nodules. Many of the shells have a reddish or brownish tint. Most live in shallow water on rocky shores or coral though some live on sandy substrate. They are carnivorous, feeding on other mollusks, worms and barnacles. Fasciolarids have only 1 sex: female. Their eggs develop without being fertilized. There are 8 species found in Texas.

Banded tulip Page 263 Fasciolaria lilium Family Fasciolariidae - gastropods

Gastropod (1 shell); shell spiral in shape, elongate; smooth with minute growth Distinguishing rings; color off-white to light brown with some reddish brown mottling; thin Characteristics brown or dark spiraling lines, widely spaced, unbroken; spire high and pointed; medium length siphonal canal, curved; aperture oval, pointed at the top. Similar to the true tulip (F. tulipa), but the true tulip's spiraling lines are much Similar Species closer together. The banded tulip does not get as large as the true tulip. Habitat Gulf and bay, sandy or muddy bottoms Maximum Size 10.3 cm (4 in) Previous Scientific F. hunteria Names

True tulip Page 264 Fasciolaria tulipa Family Fasciolariidae - gastropods

Gastropod (1 shell); shell spiral in shape; color grayish to cream background with brown or red mottling with dark spiraling, narrow-spaced lines or grooves; Distinguishing spire medium, pointed; 8-9 whorls, irregular axial growth lines; beading just Characteristics below suture lines; aperture oval, pointed above, inner lip with elongate grooves (dentate); siphonal canal medium length. Similar in shape to the banded tulip, F. lilium, but the banded tulips spiraling Similar Species lines are more widely spaced than the true tulip. Habitat Gulf and bay, sandy or muddy bottoms, seagrass beds Maximum Size 25 cm (10 in)

Tonnidae - Tun Snails Page 265

Tonnidae, the tun snails, have a broad, oval shaped shell with a large aperture. In the adult form, they lack an operculum. They inhabit soft substrate in shallow to deep tropical marine waters. When not feeding, they will usually bury themselves in the substrate leaving only the tip of their siphon exposed. They are carnivorous, feeding mainly on sea cucumbers (holothurians). They are represented by 2 species in Texas.

Giant tun Page 266 Tonna galea Family Tonnidae - gastropods

Gastropod (1 shell); shell spiral in shape; color white to light brown, sometimes mottled; body whorl makes up most of shell; grooves (sutures) between whorls Distinguishing deep; spire small; spiraling ribs, some alternating between high and low ribs; Characteristics aperture large, outer margin scalloped, ridge near outer margin in adults; columella (central axial part) twisted with a ridge on outer margin; short, abrupt siphonal canal. Similar to the partridge tun (T. pennata) which is narrower and has a higher Similar Species spire. Habitat Gulf and bay, sandy bottoms Maximum Size 16 cm (6 1/3 in)

Epitoniidae - Wentletraps Page 267

Epitoniidae, the wentletraps, usually have tall, cone-shaped shells with small apertures. Their spire is usually very long. The shells generally have blade-like axial ribs. Many are very small, not exceeding 1 inch in length. Wentletraps are carnivorous, eating mainly on sea anemones and coral. Besides their raspy tongue, they have jaws that can bite off chucks of their prey. They may live attached to their prey or in sand or rubble substrate. Texas has 23 species of wentletraps.

Angulate wentletrap Page 268 Epitonium angulatum Family Epitoniidae - gastropods

Gastropod (1 shell); shell spiral in shape, elongate, with 9-10 blade-like axial ridges (costae) on whorls, slightly bent backwards; color white; about 6-8 Distinguishing smooth whorls that do not touch except where ridges cross; blade on ridges Characteristics with angle on shoulder; spire pointed; no umbilicus (sunken depression at base of shell); aperture oval, thickened, slightly bent backwards. Most like Humphrey's wentletrap. Humphrey's wentletrap has hook-like blades Similar Species on upper whorls and blades are thicker on lower whorls. Humphrey's also has more whorls (9-10 vs. 6-8) and is narrower at the bottom. Habitat Gulf, sandy bottoms Maximum Size 2.5 cm (1 in)

Semismooth wentletrap Page 269 Epitonium apiculatum Family Epitoniidae - gastropods

Gastropod (1 shell), shell spiral in shape, elongate, with 8-9 whorls, sutures between whorls distinct, deep; color white; blade-like axial ribs (costae) on Distinguishing whorls, upper edges of costae rounded, not angular; area between costae Characteristics smooth (no spiraling threads); whorls at the tip of the spire smooth with little to no costae; next 2-3 whorls with low ridge-like costae more numerous than the lower whorls; aperture opening round with thickened lip. This wentletrap is distinguished by its thickened aperture lip, no spiraling Similar Species threads between costae, rounded shoulders on costae, the smooth top whorls, and the more numerous costae on the upper whorls. Habitat Gulf, sandy bottoms Maximum Size 0.5 cm (1/5 in) Other Common Names Dall's wentletrap

Tollin's wentletrap Page 270 Epitonium tollini Family Epitoniidae - gastropods

Gastropod (1 shell); shell spiral in shape, elongate, with 8-10 whorls; color white; blade-like or rounded raised axial ridges (costae) on whorls, round at the shoulders; whorls attached to each other; axial ridges usually lined up Distinguishing (occasionally misaligned) and attached to adjacent upper and lower ridges; Characteristics occasional ridge thicker than others; surfaces between ridges smooth; aperture oval with thickened outer lip; spire pointed; no umbilicus (sunken depression at base of shell). Distinguished from other wentletraps by having the whirls attached to each Similar Species other (some others have whirls only attached at the ridges),smooth surfaces between ridges (no spiral threads), and rounded shoulders on ridges. Habitat Gulf, shallow water Maximum Size 1.3 cm (1/2 in)

Melongenidae - Whelks and Crown Conchs Page 271

Melongenidae contains the busycon whelks and crown conch. Their shells typically have a broad body whorl with a long and narrow or short and wide siphonal canal. They are carnivorous and feed mostly on bivalves. They use their massive foot to cover the bivalve and pry the shells apart. They then wedge their shell between the bivalve shells and extend their feeding apparatus (proboscis) inside the clam. There are 4 species found in Texas, including the lightning whelk, the state shell of Texas.

Lightning whelk Page 272 Busycon pulleyi Family Melongenidae - gastropods

Gastropod (1 shell); shell spiral in shape, left-handed (sinistral); shell color with off-white to tan or gray with brown or dark radial streaks, streaks disappear in adults, band of lighter color at the lower curve of the body whorl; small short projections outlining the whorls; spiraling ridges on whorls; spire is short to Distinguishing medium; aperture is oblong with a definite angle at the top of the 1st whorl; Characteristics inside aperture is white, yellow or gray, sometimes with brown streaks, slightly grooved; aperture usually opens on the left side (looking at the aperture side), but right-handed shells do occur; siphonal canal long; snail body is black or dark. Looks like a splendid whelk but the aperture opens to the left (sinistral). Similar Species According to the experts, this is the only sinistral (left-handed) whelk on the Texas coast. Habitat Gulf and bay Maximum Size 41 cm (16 in) Previous Scientific B. perversum pulleyi, B. perversum, B. contrarium, B. sinistrum Names

Pearwhelk Page 273 Busycotypus spiratus Family Melongenidae - gastropods

Gastropod (1 shell); shell spiral in shape, right-handed (dextral); shell color whitish yellow with irregular wavy radial brown streaks, lighter colored band at base of body whorl; spiraling ridges on whorls; no projections on edges of body Distinguishing whorl, may or may not be small projections on edges of other whorls; deep Characteristics groove between whorls; edges of body whorl gently rounded, not angular; aperture oblong, long, about 3/4 the length from body whorl to tip of siphon, inside white to light brown; spire short; siphonal canal long; snail body is pale orange. The shouldered pear whelk has nodules on the edges of whorls (absent on the pear whelk), has an angular aperture opening (a shoulder), spiral is step-like Similar Species with no grooves between the whorls and its aperture opening is slightly shorter than the pearwhelk's. Habitat Gulf, sandy bottoms Maximum Size 15 cm (6 in) Previous Scientific Busycon spiratum plagosum Names

Shouldered pearwhelk Page 274 Busycotypus plagosus Family Melongenidae - gastropods

Gastropod (1 shell); shell spiral in shape, right-handed (dextral); shell color off- white with irregular radial brown streaks; slightly wavy spiraling ridges on whorls; projections on edges of whorls low, smooth, nodule-like; aperture Distinguishing oblong, long, about 2/3 the length from body whorl to tip of siphonal canal, Characteristics inside white to brownish purple; aperture with 2 angular turns, 1 near whorl and other a short distance from 1st angle, 2nd angle with no nodule present; spire short to medium, step-like, pointed; siphonal canal long; snail body is pale orange. The pearwhelk has no nodules on the edges of the 1st whorl, its aperture Similar Species opening is curved, not angulate, has a groove between whorls, and its aperture opening is longer. Habitat Gulf, sandy bottoms Maximum Size 15 cm (6 in) Previous Scientific Busycon spiratum plagosum Names

Splendid whelk Page 275 Busycon candelabrum Family Melongenidae - gastropods

Gastropod (1 shell); shell spiral in shape, right-handed (dextral); shell color with off-white to tan or gray with brown or dark radial streaks, band of lighter color on the lower curve of the body whorl; small short projections outlining the Distinguishing whorls; spiraling ridges on whorls; spire is short; aperture is oblong with a Characteristics definite angle at the top of the 1st whorl, short, take up less than 1/2 total body length; inside aperture is white, yellow or gray, sometimes with brown streaks, grooved; aperture opens on the right side (looking at the aperture side); siphonal canal long, slight twist towards the bottom; snail body is black or dark. Looks like a lightning whelk but the aperture opens to the right (dextral). Pear Similar Species whelks (also dextral) have longer aperture openings. Habitat Gulf and bay Maximum Size 23 cm (9 in)

Buccinidae - True Whelks Page 276

Buccinidae, the true whelks, have a variety of shapes. They are usually characterized as having strong sutures, a smooth spiraling surface and can reach up to 26 cm (10 in). However, most of the ones found in Texas are smaller (<5 cm or 2 in) with strong radial nodulose ribs and a strong spire. Habitat is also variable, some living on soft substrates while others are adapted to hard substrates. They are carnivorous and opportunistic scavengers, eating other invertebrates, carrion and sometimes detritus. Many will use the flared lip of their aperture to pry open the shells of bivalves to prey on. There are 8 species of Buccinidae in Texas.

Cancellate cantharus Page 277 Solenosteira cancellaria Family Buccinidae - gastropods

Gastropod (1 shell); shell spiral in shape; color yellowish to reddish brown, with Distinguishing white areas; inside aperture white; spiraling and radial ribs, beaded at the Characteristics intersections of ribs; spire high, pointed; siphonal canal short, slightly turned; aperture long, outer margin crenate (scalloped), fine dentations on inner edge. Similar Species The shape and beaded appearance distinguish this species. Habitat Gulf mostly, bays with higher salinities, jetties Maximum Size 3.6 cm (1 2/5 in) Previous Scientific Cantharus cancellarius Names

Turritellidae - Wormsnails and Turretsnails Page 278

Turritellidae, the wormsnails and turretsnails (also called tower snails, screw snails and true augers) have long, slender, screw-like or turreted shells, generally with strong spiraling cords. The shells lack a siphonal canal. In the wormsnails, the older whorls of the spire separate and become loosely and erratically coiled, resembling the shells of some annelid worms. Most turritellids are free-living though some will attach themselves to hard objects. Unlike most gastropods which are carnivores, turritellids are filter feeders. They filter out fine food particles suspended in the water column or may burrow and feed on small particles of detritus. This feeding method is more common to bivalves. There are 4 species of turritellids found in Texas.

Fargo's wormsnail Page 279 Vermicularia fargoi Family Turritellidae - gastropods

Gastropod (1 shell); shell spiral in shape, spire elongate, pointed; color tan to Distinguishing reddish brown; 3 spiral ribs on lower whorls; very fine axial ribs; young with Characteristics whorls attached to each other, tightly coiled; older snails with lower whorls detached, spiraling worm-like; aperture squarish; siphonal canal absent. Most similar to the white-tipped wormsnail (V. knorrii), but the upper whorls on the white-tipped are white. Turritellids are similart to the auger shells Similar Species (Terebridae), but the circular aperture and lack of a siphonal canal distinguishes the turritellids from the terebrids. Habitat Gulf and bays, attached to rocks or on mud bottoms Maximum Size Tighter coils about 1.8 cm (3/4 in), with detached whorls about 8 cm (3 in) Other Common Names West Indian wormsnail Previous Scientific V. spirata Names Has not been found live in Texas, but shells are common on the beach in south Comments Texas.

Page 280

Echinolittorina interrupta Aliger gallus murex, Beau's Epitonium angulatum Angulate wentletrap murex, Giant eastern Aplysia fasciata Epitonium apiculatum nassa, Bruised Epitonium tollini Architectonica nobilis nassa, Sharp False shark eye armina, Brazilian Nassarius acutus Fargo's wormsnail Armina muelleri Nassarius vibex Fasciolaria lilium Arrow squid Nerita versicolor Fasciolaria tulipa Atlantic brief squid nerite, Four-toothed Fat dovesnail auger, Fine-ribbed nerite, Virgin Fine-ribbed auger auger, Gray Atlantic Neritina virginea Florida rocksnail auger, Marylee's Neverita delessertiana Four-toothed nerite auger, Salle's Neverita duplicata Giant eastern murex baby ear, White nudibranch, Brazilian armina Giant tun Banded tulip nudibranch, Sargassum Graptacme perlonga Beau's murex octopus, Common Gray Atlantic auger Brazilian armina Octopus vulgaris Hastula cinerea Bruised nassa Oliva sayana Hastula maryleeae Busycon candelabrum olive, Lettered Hastula salleana Busycon pulleyi Parvanachis obesa Hawkwing conch Busycotypus plagosus Pearwhelk Hays' rocksnail Busycotypus spiratus pearwhelk, Shouldered Cancellate cantharus helmet, Reticulated cowrie periwinkle, Interrupted cantharus, Cancellate Hexaplex fulvescens periwinkle, Marsh Cerberilla tanna Interrupted periwinkle Ram’s horn squid Chicoreus beauii Janthina Reticulated cowrie helmet Common Atlantic slippersnail Janthina janthina rocksnail, Florida Common octopus Lettered olive rocksnail, Hays' Common sundial Lightning whelk Roostertail conch conch, Hawkwing limpet, Striped false Salle's auger conch, Roostertail Littoraria irrorata Sargassum nudibranch Convex slippersnail Lobatus raninus Scyllaea pelagica Costoanachis translirata Loligo pealeii sea hare, Mottled cowrie helmet, Reticulated Loligo pleii sea slug, Cream colored cowrie, Measled Lolliguncula brevis Semismooth wentletrap Cream colored sea slug Longfin inshore squid Shark eye Crepidula convexa Macrocypraea zebra shark eye, False Crepidula depressa Marsh periwinkle Sharp nassa Crepidula fornicata Marylee's auger Shouldered pearwhelk Cypraecassis testiculus Measled cowrie Sinum perspectivum Dondice occidentalis Melampus bidentatus Siphonaria pectinata dondice, Western melampus, Eastern Slender tuskshell dovesnail, Fat Miniature moonsnail slippersnail, Common Atlantic dovesnail, Well-ribbed moonsnail, Miniature slippersnail, Convex Eastern melampus Mottled sea hare slippersnail, Eastern white Eastern white slippersnail

Page 281

Solenosteira cancellaria Spirula spirula Splendid whelk squid, Arrow squid, Atlantic brief squid, Longfin inshore squid, Ram’s horn Stramonita canaliculata Stramonita haemastoma Striped false limpet sundial, Common Tectonatica pusilla Terebra protexta Tollin's wentletrap Tonna galea True tulip tulip, Banded tulip, True tun, Giant tuskshell, Slender Vermicularia fargoi Virgin nerite Well-ribbed dovesnail wentletrap, Angulate wentletrap, Semismooth wentletrap, Tollin's Western dondice whelk, Lightning whelk, Splendid White baby ear wormsnail, Fargo's Page 282 Marine Cephalopods of Texas

Longfin inshore squid Arrow squid Atlantic brief squid Common octopus Loligo pealeii Loligo pleii Lolliguncula brevis Octopus vulgaris Family Loliginidae Family Loliginidae Family Loliginidae Family Octopodidae

Ram's horn squid Spirula spirula Family Spirulidae

Marine Scaphopods of Texas

Slender tuskshell Graptacme perlonga Family Dentaliidae

Page 283 Page 284 Octopodidae - Octopods

Octopodidae contains the majority of the octopus species of the world. They are in the Phylum Mollusca which also contains the hard-shelled bivalves and gastropods. Although their closest cousins, the squids and cuttlefishes, have retained a highly reduced semblance of an internal shell, most octopods have no internal or external shell at all. They also differ from squids and cuttlefishes by having 8, instead of 10, arms. The arms are webbed and have 1 or 2 series of suckers extending down the lower sides. In males, one of the 3rd arms is modified into a mating apparatus with a spoon-like tip and a sperm groove running up the edge of the arm. Octopods have a short life span (1-2 years). The male usually dies after mating. The female watches over her brood of eggs until the last one hatches and then dies.

Having no internal shell, the body of the octopods is highly flexible and changeable. Their skin colors are highly variable, and they can change their skin pigment to camouflage themselves by mimicking their background. They also change their skin color to communicate with other octopods. Movement though the water is by jet propulsion (squirting water through a funnel) or by flapping their webbed arms. Two species are known to walk bipedally (as on 2 legs).

Most octopods have an ink sac which produces a dark cloud in the water used to detract and confuse predators. They also have sharp beak-like mouths that can cause nasty bites. Some are poisonous. The blue ring octopus, found in Australia and Southeast Asia, is known for its venomous bite. Its saliva contains tetrodotoxin, similar to that of the puffers, that can paralyze muscles and kill the victim within hours. However, the poison is not produced by the octopus itself but by the bacteria found in its saliva.

Octopods live in holes in coral, rocks or rubble or they burrow into sandy bottoms. Their diet mainly consists of crustaceans, and their lairs can sometimes be identified by the remains of prey and other rubble scatter outside the opening. Some octopods will eat a variety of prey, including other octopods, while some will only eat one certain type of prey. A few will even eat their own species.

Page 285 Common octopus Octopus vulgaris Family Octopodidae - cephalopods

Head globular; 8 arms with suckers attached to head; color variable, usually mottled reddish brown; texture smooth or with points; arms stout, 3-4 times the Distinguishing body length, arms about equal in length, dorsal arms slightly shorter; 2 Characteristics longitudinal rows of suckers on arms, dark rings around the suckers; no distinct bars, bands or spots; no blue rings below eyes. Similar Species Other octopi have markings (bands, bars, spots) or short arms or unequal arms. Habitat Reefs, rocks, grass beds Maximum Size 130 cm (51 in) total length, 40 cm (15 3/4 in) mantle length

Page 286 Loliginidae and Spirulidae - Squids

Squids are marine cephalopods which include octopuses, cuttlefishes and the nautilus. They belong to the phylum Mollusca and are related to gastropods and bivalves, but unlike their hard-shelled cousins, squids do not have an external shell. They have a remnant of a shell, internally, called a pen or gladius. The gladius is long, slim and very thin and flexible. (The ram's horn squid internal shell is a chambered, coiled structure.) Squids have an outer body called the mantle with two lateral fins. The fins are used for balance and steering more than for locomotion. A siphon behind the eyes provides propulsion and expels waste. Attached to the mantle are the eyes, the beak-like mouth, eight arms and two longer retractable tentacles. The underside of the arms and the ends of the tentacles are covered with suckers.

Squid have the ability to rapidly change their colors and color patterns to camouflage themselves with the surrounding background. They also protect themselves by squirting black mucous ink into the water to confuse their predators. Some squid produce bioluminescence which is another method of protection because the light they produce disguises their contours in surrounding dark waters.

Squids travel in large schools. Most undergo diel (24-hour) vertical migration, where they may occur at depths of 200 to 400 m during the day and then migrate to surface waters at night. There are extensive commercial fisheries for squid, worldwide. In the U.S. they are commonly marketed as "calamari". Squids are also important in many biomedical researches. They have highly developed brain and sensory organs and have the capacity to learn and remember. This makes them valuable for behavioral and neurological studies.

The family Spirulidae contains only one species, Spirula spirula, the deepwater ram's horn squid.

Page 287 Arrow squid Loligo pleii Family Loliginidae - cephalopods

Body (mantle) cylindrical, long, slender, tip pointed, males more slender with longer fins than females; lateral fins longer than wide, not exceeding 50% of mantle length, (if mantle length >12 cm (4 3/4 in), fins may be up to 50% or slightly greater than mantle length); outer edges at a blunt angle (not rounded), sides nearly straight; eyes nearly lateral; has a funnel behind the eyes; 8 short Distinguishing arms (shorter than mantle length) with sucker on the undersides extending the Characteristics length of the arms; 2 longer tentacles with suckers only on the ends, ends spatulate shaped; mouth with beak-like teeth; color translucent with many purple-red pigment cells (chromatophores) on entire body; the internal pen has a vane width/rachis width ratio of 2.4 or less, edges are usually straight, and usually has ridges. The arrow squid is more slender and firm than the brief squid, its mantle tip is hard and pointed; its fins are long and rhomboidal shaped, it usually more chromatophores than the brief squid; It is not as slender with shorter fins Similar Species (usually <50% of mantle length) than the longfin inshore squid; its pen is narrower at the vane usually with straight edges and usually with ridges; the pen of the longfin inshore squid is wider usually with curved edges and usually has no ridges. Habitat Gulf, pelagic Maximum Size 40 cm (15 3/4 in) mantle length Other Common Names slender inshore squid Previous Scientific L. pleii, Doryteuthis plei Names Page 288 Atlantic brief squid Lolliguncula brevis Family Loliginidae - cephalopods

Body (mantle) cylindrical, stout, bluntly rounded at tip; lateral fins short, broad, rounded, wider than long; eyes nearly lateral; has a funnel behind the eyes; 8 Distinguishing short arms (shorter than mantle length) with sucker on the undersides Characteristics extending the length of the arms; 2 longer tentacles with suckers only on the ends, ends spatulate shaped; mouth with beak-like teeth; color translucent with many purple-red pigment cells (chromatophores) on entire body. The brief squid mantle is floppy, not as slender as other squids, has a blunt Similar Species mantle tip, and is usually not as pigmented as the other squids. Habitat Gulf and bay Maximum Size 12.7 cm (5 in) mantle length

Page 289 Longfin inshore squid Loligo pealeii Family Loliginidae - cephalopods

Body (mantle) cylindrical, long, slender, tip pointed, lateral fins longer than wide, exceeding 50% of mantle length in specimens with mantle length > 7 cm (2 3/4 in); outer edges at a blunt angle (not rounded), sides nearly straight; eyes nearly lateral; has a funnel behind the eyes; 8 short arms (shorter than mantle Distinguishing length) with suckers on the undersides extending the length of the arms; 2 Characteristics longer tentacles with suckers only on the ends, ends spatulate shaped; mouth with beak-like teeth; color translucent with many reddish pigment cells (chromatophores) on entire body; the internal pen has a vane width/rachis width ratio of 2.4 or greater, edges are usually curved, usually with no ridges. The longfin inshore squid is more slender and firmer than the brief squid, its mantle tip is hard and pointed; its fins are long and rhomboidal shaped, it usually more chromatophores than the brief squid; It is more slender with Similar Species longer fins (usually >50% of mantle length) than the arrow squid; its pen is wider at the vane usually with curved edges and rarely with ridges; the pen of the arrow squid is narrower usually with straight edges and usually has ridges. Habitat Gulf, pelagic Maximum Size 50 cm (19 3/4 in) mantle length; usually less than 30 cm (11 3/4 in) Previous Scientific L. pealei, Doryteuthis pealeii Names

Page 290 Ram's horn squid Spirula spirula Family Spirulidae - cephalopods

Body (mantle) cylindrical, short, rounded tip; color reddish brown to pale pink; posterior end (tip) with 2 small rounded fins; 4 pairs of short arms and 1 pair of longer tentacles; arms and tentacles with suckers; internal shell is tubular, Distinguishing tapered at one end, spiraling, spirals not touching or barely touching, Characteristics chambered, aperture round, covered inside except for small hole that leads to next chamber, color yellowish white; live specimens rarely seen; internal shell is gas-filled and may wash ashore on beaches. The ram's horn squid is smaller and squattier than squids in the Loliginidae family, and most people will never see a live one. The internal shell can be Similar Species distinguished from spiraling gastropod shells by it chambers. Gastropods live in their shells, so the shells won't be chambered. Habitat Gulf, deep waters Maximum Size squid 4.5 cm (1 3/4 in) mantle length, internal shell 2.5 cm (1 in) Other Common Names little post horn squid, tail light squid The ram's horn squids spend most of their lives in a heads down position. The gas-filled internal shell keeps the posterior end up. These squids also have a Comments light-emitting organ between the 2 posterior fins (hence, the name tail light squid).

Page 291 Dentaliidae - Tuskshells

Dentaliidae, the tuskshells, are neither bivalves or gastropods. They belong to a class of mollusks called Scaphopoda. Tuskshells are univalves with shells that are small, long, and tubular, usually slightly curved, resembling a narrow tusk. One end wider than the other end. Both ends are open. The head and foot of the animal reside at the wider end, the aperture. The narrow end, the apex, is used to draw in water and particles and expel wastes and reproductive products (sperm and eggs). Tuskshells are burrowers. The aperture end buries into the substrate leaving the apex end exposed above. They are carnivores and use their radula (a tongue-like structure with teeth) to capture prey in the sediment. They have no eyes, sensory tentacles or gills. Oxygen is absorbed from the water through the mantle (body covering). There are 6 species in Texas waters.

Page 292 Slender tuskshell Graptacme perlonga Family Dentaliidae - scaphopods

Scaphopod; shell tubular in shape, narrower at posterior end, slightly curved, Distinguishing long and slender, almost needle-like; color white, opaque; round in cross- Characteristics section; sculpture smooth, no radial ribs or grooves, faint growth lines; apex (narrow end) either with shallow notch on convex side or smooth with no notch. Other tusk shells are not as slender as this tusk shell. The Texas tuskshell (Dentalium americanum) has radial ridges and is hexagonal in shape. The ivory Similar Species tuskshell (G. eborea) has radial ridges at the apex (narrow end). The annulated tuskshell (Episiphon sowerbyi) is reported to have a tubular pipe extending from its apex and does not get as large as the slender tuskshell. Habitat Gulf, mud and sandy bottoms Maximum Size 9 cm (3 1/2 in) Previous Scientific Dentalium perlongum Names

Page 293 Other Marine Invertebrates of Texas Page 294

Warty anemone Onion anemone Many-ribbed jellyfish Brittle star Bunodosoma cavernatum Paranthus rapiformis Rhacostoma atlanticum Microphiopholis atra Family Actiniidae Family Actinostolidae Family Aequoreidae Family Amphiuridae

Thorn isopod Two-spined sea star Giant purple barnacle Reticulated striped barnacle Ancinus depressus Astropecten duplicatus Megabalanus tintinnabulum Balanus reticulatus Family Ancinidae Family Astropectinidae Family Balanidae Family Balanidae

White barnacle Bay barnacle Striped barnacle Purple striped barnacle Balanus subalbidus Balanus improvisus Balanus amphitrite amphitrite Balanus trigonus Family Balanidae Family Balanidae Family Balanidae Family Balanidae

Ivory barnacle Striped barnacle Sea walnut Clinging jellyfish Balanus eburneus Amphibalanus venustus Beroe ovata Nemopsis bachei Family Balanidae Family Balanidae Family Beroidae Family Bougainvilliidae

Spiral-tufted bushy bryozoan Hidden cup coral Sea wasp Fragile barnacle Bugula nertina Phyllangia americana Chiropsalmus quadrumanus Chthamalus fragilis Family Bugulidae Family Caryophylliidae Family Chiropsalmidae Family Chthamalidae

Sea whip Tricolor anemone Small goose barnacle Smooth goose barnacle Leptogorgia setacea Calliactis tricolor Lepas pectinata Lepas anatifera Family Gorgoniidae Family Hormathiidae Family Lepadidae Family Lepadidae

Page 295

Goose barnacle Gray sea star Dark-banded mantis shrimp Australian spotted jellyfish Lepas anserifera Luidia clathrata Lysiosquilla scabricauda Phyllorhiza punctata Family Lepadidae Family Luidiidae Family Lysiosquillidae Family Mastigiidae

Sand dollar Sea grape Common clam worm Diffuse ivory bush coral Mellita quinquiesperforata Mogula manhattensis Alitta succinea Oculina diffusa Family Mellitidae Family Mogulidae Family Nereididae Family Oculinidae

Banded brittle star Rosette-scaled brittle star Purple-striped jellyfish Sea nettle Hemipholis elongata Ophiolepis elegans Pelagia noctiluca Chrysaora quinquechirrha Family Ophiactidae Family Ophiuridae Family Pelagiidae Family Pelagiidae

Sea cucumber Portuguese man o' war Marine leach By the wind sailor Allothyone mexicana Physalia physalis Calliobdella vivida Velella velella Family Phyllophoridae Family Physaliidae Family Piscicolidae Family Porpitidae

Blue button Sea pansy Northern cup coral Cannonball jellyfish Porpita porpita Renilla muelleri Astrangia poculata Stomolophus meleagris Family Porpitidae Family Renillidae Family Rhizangiidae Family Rhizostomatidae

Mushroom jellyfish Ridged slipper lobster Offshore mantis shrimp Mantis shrimp Rhopilema verrilli Scyllarides nodifer Squilla chydaea Squilla empusa Family Rhizostomatidae Family Scyllaridae Family Squillidae Family Squillidae

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Lesser mantis shrimp Pleated sea squirt Beneden's sea cucumber Moon jellyfish Gibbesia neglecta Styela plicata Protankyra benedeni Aurelia aurita Family Squillidae Family Styelidae Family Synaptidae Family Ulmaridae

Sauerkraut bryozoan Alternating bryozoan Pipe cleaner sea pen Zoobotryon verticillatum Amathia alternata Virgularia presbytes Family Vesiculariidae Family Vesiculariidae Family Virgulariidae Lepadidae, Balanidae, Chthamalidae - Barnacles Page 297

Barnacles are sedentary crustaceans (related to shrimp and crabs) that are usually found attached to hard substrates. They will attach to just about any solid object, including other barnacles and mammals such as whales. Most are covered with a set of overlapping hard calcareous plates that protect the body. Some, like the goose barnacle, have a stalk (peduncle) that attaches to hard surfaces and can extend the body out. Others, like the acorn barnacles, have no stalk and the body, covered by its plates, attaches directly to the hard surface. A set of feather-like appendages extend from the plates to filter the water for food. Adult barnacles can secrete substances that attract barnacle larvae to the area. That way they can form dense populations, making it easier to reproduce. Since many are found around jetties and other intertidal areas, they can adapt to dry conditions by closing their plates tightly to conserve moisture.

In Texas, a parasitic barnacle, Loxothylacus texanus, invades the bodies of blue crabs. A female larva injects a blob of cells into the crab through the crab's carapace. The larva dies and the blob of cells become the adult parasite. It grows in the crab, wrapping itself around the crab's internal organs. The barnacle stunts the growth of the crab and adjusts the crab's hormones so that both juvenile male and female crabs take on the appearance of a mature female crab by widening the abdominal flap. The crab becomes infertile and is unable to molt or regenerate its appendages. The barnacle finally protrudes to the outside the abdomen of the crab as a bulging sac, resembling an egg-carrying female crab. The sac carries the eggs of the barnacle. When the eggs are fertilized by a male barnacle, the crab carries and nurtures the barnacle's eggs until they hatch. The barnacle remains with the crab until the crab dies and may reproduce several times while the crab remains small and unreproductive for the rest of its life.

Bay barnacle Page 298 Balanus improvisus Family Balanidae - barnacle (crustacean)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates; walls (radii) narrow at top, disappear at base with plates (parietes) touching or nearly so; plates are whitish, smooth; no horizontal Distinguishing striations; base plate is calcareous, usually stays on hard substrate when Characteristics barnacle is removed; base plate with radial patterns; aperture diamond-shaped; opercular plates at the aperture with radial grooves; internal plate (tergum) with long spur (rounded extension), less than 1/4 the width of the basal margin. May be confused with B. subalbidus. The walls (radii) of B. subalbidus are usually more narrow, sometimes almost nonexistent, at least in the conical specimens. B. improvisus has a radially grooved base. The best way to Similar Species distinguish these two is by looking at the terga. B. improvisus has a long spur, and B. subalbidus has a short, wide spur. Though sometimes found together, B. improvisus prefers less saline waters than B. subalbidus. Habitat Bay, in lower salinities Maximum Size 2 cm (3/4 in), usually less than 1 cm Previous Scientific Amphibalanus improvisus Names

Fragile barnacle Page 299 Chthamalus fragilis Family Chthamalidae - barnacle (crustacean)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates; walls (radii) very narrow to nonexistent; plates are grayish in color; base of plates undulating; base plate is membranous as Distinguishing opposed to calcareous; orifice oval in shape; opercular plates with visible wavy Characteristics suture lines in center (junction of the tergum and scutum); internal plate tergum with small spur fused to basal margin; internal plate scutum triangular, curved at base with distinct angled corner. The gray color and visible wavy suture lines on the opercular plates help Similar Species distinguish this species. Habitat Gulf, intertidal, around jetties and pilings Maximum Size 0.5 cm (1/5 in) Other Common Names little gray barnacle

Giant purple barnacle Page 300 Megabalanus tintinnabulum Family Balanidae - barnacle (crustacean)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates, horizontal striations between plates; color of plates pink Distinguishing to pinkish purple, walls (radii) in between plates with a lighter color, either Characteristics whitish or light purple; aperture usually round; may be striped and ribbed longitudinally; aperture 1/3 to 2/3 the diameter of the base. This is most common large pink barnacle in our area. Another non-native Megabalanus, the titan acorn barnacle (M. coccopoma), has been found around the Florida area and the east coast. Distinguishing it from this barnacle Similar Species is difficult without examining the internal shell parts, which are usually missing when these barnacles wash ashore. The titan acorn barnacle is usually a deep red color with a small (<1/2 basal diameter) aperture. Gulf, usually attaches to platforms, washes up on beaches in clumps after Habitat storms Maximum Size 5 cm (2 in) (height) Previous Scientific M. antillensis, Balanus tintinnabulum Names

Goose barnacle Page 301 Lepas anserifera Family Lepadidae - barnacle (crustacean)

Shelled body flat, triangular shaped, wide at the bottom, narrows to a point, compressed; 5 calcareous plates, plates overlap, no gaps in between, color off- white, orange color at edges of plates; plates have radiating ridges and grooves; upper trapezoid-shaped plate (tergum) usually more striated than the Distinguishing wide quadrangular lower plate (scutum); narrow singular plate (carina) forked at Characteristics the bottom to an angle of 90° or more; rounded ridge from lower area near beak to apex of scutum plate; no holes or spots on sides of scutum plates; fleshy stalk (peduncle) between shell and substrate used to attach to substrate, usually as long as the shelled part (capitulum), may be hidden in shell, orange in color; feathery appendages extend from opposite end of shell when feeding; The smooth goose barnacle, Lepas anatifera, does not have radiating grooves (sometimes a few on the scutum by never on the tergum), and its peduncle is purplish brown. Also in smooth goose barnacle, the forks at the end of the carina are imbedded in tissue and cannot be seen. The carinal forks on L. Similar Species anserifera are not embedded in tissue and are clearly visible (with magnification). The small goose barnacle L. pectinata is smaller and usually found on sargassum. Its peduncle is brown and yellow. It has deep radiating lines crossed by well-defined growth lines. Habitat Gulf, found attached to floating debris Maximum Size 4 cm (1 1/2 in) capitulum length (shelled part) Other Common Names goose-neck barnacle

Ivory barnacle Page 302 Balanus eburneus Family Balanidae - barnacle (crustacean)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates; plates set close together at the base, diverge at the top, walls between wider at the top; sometimes plates extend past the walls giving Distinguishing an undulating or toothed appearance to aperture; plates are whitish, smooth; Characteristics aperture is diamond-shaped except one point is flat; internal opercular plates distinctly striated longitudinally; base plate is calcareous, usually stays on hard substrate when barnacle is removed; tergum spur fairly long with basal margin curved, angular. The ivory barnacle can be distinguished from most common barnacles by the longitudinal striations on its scutum (can be seen with the naked eye in larger specimens, or with magnifying glass in smaller ones). Most other barnacles Similar Species scuta have radial striations. The ivory barnacle also has a deeply concaved basal margin of the tergum. This barnacle gets larger than most other common barnacles. Habitat Gulf nearshore and bay Maximum Size 2.5 cm (1 in)

Purple striped barnacle Page 303 Balanus trigonus Family Balanidae - barnacle (crustacean)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates, plates usually with purple background and fine white Distinguishing vertical ridges (stripes), walls (radii) in between plates white to purple, smooth; Characteristics aperture triangular; the small internal plates that close the shell opening (scutum) have distinctive rows of small pits. There are several purplish stripe barnacles in our area. The most distinguishing Similar Species feature of this barnacle is the triangular-shaped aperture. Habitat Gulf, bays rarely Maximum Size 2 cm (3/4 in)

Reticulated striped barnacle Page 304 Balanus reticulatus Family Balanidae - barnacle (crustacean)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates; walls (radii) narrow with oblique outer edge; plates with irregularly spaced vertical dark, reddish purple or brown stripes; horizontal Distinguishing striations give the plates a reticulated pattern; base plate is calcareous, usually Characteristics stays on hard substrate when barnacle is removed; aperture is almost diamond-shaped except flat or rounded at 1 end; internal plate (tergum) with spur (rounded extension) longer than wide. There are several purplish stripe barnacles in our area. Similar to the striped Similar Species barnacle B. amphitrite but the striped barnacle has no reticulated pattern. Also, the striped barnacle has a short tergal spur (about as wide or wider than long). Habitat Gulf, attaches to platforms and other hard surfaces Maximum Size 1.5 cm (3/5 in)

Small goose barnacle Page 305 Lepas pectinata Family Lepadidae - barnacle (crustacean)

Shelled body flat, triangular shaped, wide at the bottom, narrows to a point, compressed; 5 calcareous plates, plates overlap, no gaps in between, color off- white to bluish, sometimes with brown stripes crossing radial ridges; plates have radiating ridges and grooves, sometimes with strong spines; lower plates (scuta) triangular or quadrangular with well-defined growth lines, has the Distinguishing radiating ridges, sometimes with a cross-hatch look; upper plates (terga) nearly Characteristics triangular but may have flat top, have a notch on the margin by the scuta; narrow singular side plate (carina) forked at the bottom, sometimes heavily barbed; fleshy stalk (peduncle) between shell and substrate used to attach or substrate, usually as long or shorter than shelled part (capitulum), may be hidden in shell, brownish to yellowish in color; feathery appendages extend from opposite end of shell when feeding; Like the goose barnacle, L. anserifera, the small goose barnacle has radial striations, possibly somewhat deeper and wider than the L. anserifera. L. Similar Species anserifera rarely has a barbed carina and its terga does not have a notch on its margin by the scuta. Also the small goose barnacle has well-defined growth lines. Habitat Gulf, found attached to floating debris, common on gulfweed (Sargassum) Maximum Size 1.5 cm (1/2 in), smaller than other goose barnacles

Smooth goose barnacle Page 306 Lepas anatifera Family Lepadidae - barnacle (crustacean)

Shelled body flat, triangular shaped, wide at the bottom, narrows to a point, compressed; 5 calcareous plates, plates overlap, no gaps in between, color off- white, orange color at edges of plates; wide quadrangular lower plates (scutum) smooth or minutely striated, without distinct radiating ridges and grooves; upper triangular or trapezoid-shaped plates (tergum) smooth; ; narrow singular plate Distinguishing (carina) forked at the bottom, forks embedded in tissue, sometimes with barbs Characteristics on outer edge; rounded ridge from lower area near beak to apex of scutum plate; may have 1 to 2 radiating rows of holes or spots on sides of scutum plates; fleshy stalk (peduncle) between shell and substrate used to attach to substrate, as long or longer than shelled part (capitulum), may be hidden in shell, purplish brown in color, feathery appendages extend from opposite end of shell when feeding; The goose barnacle, Lepas anserifera has radiating grooves on the scutum and especially on the tergum, and its peduncle is orangish. Also in L. anserifera, the forks at the end of the carina are not imbedded in tissue and can be clearly Similar Species seen (with magnification). The carinal forks on the smooth goose barnacle are embedded in tissue and are cannot be seen. The small goose barnacle L. pectinata is smaller and usually found on sargassum. Its peduncle is brown and yellow. It has deep radiating lines crossed by well-defined growth lines. Habitat Gulf, found attached to floating debris Maximum Size 5 cm (2 in) capitulum length (shelled part) Other Common Names pelagic goose-neck barnacle, smooth goose-neck barnacle

Page 307 Striped barnacle Amphibalanus venustus Family Balanidae - barnacles (crustacea)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates; walls (radii) narrow; plates have regularly spaced narrow Distinguishing vertical reddish purple stripes of equal width (appears almost solid reddish Characteristics purple), plates somewhat smooth with no vertical ridges, no horizontal grooves; base plate is calcareous; aperture is basically oval, a little pointed at 1 end; internal plate tergum with spur (rounded extension) wider than long The other "striped barnacle", B. amphitrite amphitrite, has purplish stripes of varying width and spacing (more white space). The purple striped barnacle, B. Similar Species trigonus, is distinguished by its triangular opening. The reticulated striped barnacle, B. reticulatus, has horizontal grooves, giving it a reticulated pattern. Habitat Gulf, intertidal to upper shelf, attaches to hard substrates Maximum Size Not known, at least 1 cm (1/2 in) Previous Scientific Balanus venustus Names

Striped barnacle Page 308 Balanus amphitrite amphitrite Family Balanidae - barnacle (crustacean)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates; walls (radii) narrow with oblique outer edge; plates are whitish with irregularly spaced vertical dark, reddish purple or brown stripes; no Distinguishing horizontal striations; base plate is calcareous, usually stays on hard substrate Characteristics when barnacle is removed; side plates (parietes) somewhat smooth but may have shallow vertical ridges; aperture is basically diamond-shaped but flat or rounded at 1 end; internal plate tergum with spur (rounded extension) about as wide as long. There are several purplish stripe barnacles in our area. Similar to the reticulated striped barnacle, B. reticulatus, but the reticulated striped barnacle Similar Species has slight horizontal grooves giving it a reticulated pattern. It also has a longer tergal spur (longer than wide). The purple striped barnacle, B. trigonus is distinguished by its triangular opening. Habitat Gulf and bay, attaches to hard substrates Maximum Size 2 cm (3/4 in)

White barnacle Page 309 Balanus subalbidus Family Balanidae - barnacle (crustacean)

Shell conical to subcylindrical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates; walls (radii) narrow in conic specimens, wide in subcylindrical specimens; plates are whitish, smooth; no Distinguishing horizontal striations, calcareous base plate, usually stays on hard substrate Characteristics when barnacle is removed; aperture diamond-shaped except flat or rounded at 1 end; internal plate tergum with wide spur (rounded extension), about 1/3 the width of the basal margin, spur set close to the basal angle. May be confused with the bay barnacle, B. improvisus. The walls (radii) of the white barnacle are usually more narrow, sometimes almost nonexistent, at least in the conical specimens. The bay barnacle has a radially grooved base. Similar Species The best way to distinguish these two is by looking at the terga. The bay barnacle has a long spur, and the white barnacle has a short, wide spur. Though sometimes found together, the bay barnacle prefers less saline waters than the white barnacle. Habitat Bay, in lower salinities Maximum Size 1.3 cm (1/2 in)

Nereididae - Bristle Worms (Polychaetes) Page 310

Polychaetes belong the phylum Annelida, the segmented worms. The phylum also includes the classes Hirudinea, which contain the leeches, and the Oligochaeta, the earthworms. The class Polychaeta are the marine worms, such as the nereids (sandworms) and glycerids (bloodworms). Polychaetes differ from the other classes by possessing parapodia (leg-like appendages), setae (small hairs) projecting from the parapodia, and anterior appendages (antennae, palps, tentacles) which are usually lacking in the other two classes. Earthworms and leeches are also hermaphroditic (both sexes in a single individual) whereas the polychaetes are dioecious (sexes on different individuals).

Polychaetes are mostly marine with very few freshwater or terrestrial species occurring. Their habitats range from the intertidal zone to the deepest depths of the ocean, including the hydrothermal vents of the Pacific Ocean. Their class is divided into two groups, the errant polychaetes and the sedentary polychaetes. The errants are usually free swimming or crawling but sometimes will burrow in crevices or under rocks. Their parapodia and setae are well developed. Some (e.g. the fireworm) have a toxin in their setae that will produce a nasty stinging reaction in humans. The sedentaries usually live permanently in tubes or burrows or sometimes attach to rocks or pilings. This group includes the beautiful feather duster worms found in reef areas. Their appendages (parapodia) are reduced and their setae are sometimes hook-shaped to help the worm hold itself to the wall of its tube.

Nereididae worms, commonly called ragworms or clam worms, are errant polychaetes. They are characterized as having distinct heads with two pair of eyes, two palps, one pair of antennae and four pair of longer tentacles. The most common nereidid in Texas is probably the common clam worm, Alitta succinea. In the spring and summer it swarms at the surface en masse, especially at night around lights, to spawn. This increases the chance that the eggs and sperm released into the water come in contact with each other.

Common clam worm Page 311 Alitta succinea Family Nereididae - worm, marine (polychaetes)

Body wormlike; color tan to yellowish brown, sometimes with white or dark spots on body; many segmented body, up to 160 segments, each segment with a pair of arms (parapodia); parapodia numerous, occur throughout the length of the body, looks similar to a millipede; parapodia with 3-4 lobes (with multiple Distinguishing setae or hairs), cone-like anteriorly, strap-like posteriorly, posterior parapodia Characteristics greenish, yellowish or reddish when alive; head with 4 eyes, 2 bulbous palps in front of eyes, 1 pair frontal antennae, 4 pair longer tentacles; has an eversible pharynx (anterior region of the gut) with 2 tong-like jaws and numerous small teeth; The clam worm is probably the most abundant of the segmented worms (polychaetes) in the estuaries. Worms are difficult to identify. The clam worm's Similar Species distinguishing characteristic, the broad, flat straps on the posterior parapodia, distinguish it from other worms in the Nereididae family. Bays, they burrow in the sediment, can be found around seagrasses, around Habitat dock pilings, oyster reefs and other rocky bottoms Maximum Size 19 cm (7 1/2 in) Other Common Names common southern clamworm, large sandworm, ragworm, pile worm Previous Scientific Nereis succinea, Neanthes succinea, Names The clam worms are known to swarm at the surface en masse during spawning. Swarming is thought to be triggered by temperature, salinity, Comments photoperiod and lunar cycle. Commonly swarm at night near artificial lights or natural moonlight. Swarming starts around spring and may continue into summer. After reproduction, the worms die.

Page 312 Vesiculariidae and Bugulidae- Bryozoans (Moss Animals)

Bryozoans are aquatic invertebrates that can take on many different forms. They are actually a colony of polyps, called zooids, that attach to a common stalk or other hard surface. They can resemble a branching seaweed or coral or they may just encrust a hard substrate leaving an intricate lacy design on its surface. They commonly appear calcified. The distinguishing characteristic of bryozoan zooids is its feeding structure called the lophophore, a ring of ciliated tentacles surrounding a mouth. It may be horseshoe shaped or circular. However, the lophophores are so small, as are the zooids, that they cannot be seen without the help of a microscope and may be withdrawn when not feeding. Phoronids (worm-like animals) and the Brachiopods (bivalve-like animals sometimes referred to as lampshells) also possess lophophores. They are important to the ecosystem because their filter feeding filters out excess food and debris and keeps the water clear. However, they are a major fouling organism on marine structures and are likely to become alien invaders due to dispersion by ships hulls and ballast waters.

Alternating bryozoan Page 313 Amathia alternata Family Vesiculariidae - bryozoan

Colony of polyps; branching, bushy, erect; color brownish to yellowish; branching appears somewhat undulating or twisted; branching is bifurcate (splits into 2 branches at each node); tubular polyps called zooids in short, Distinguishing double rows along branches (stolons); zooid rows straight or spiraled at up to Characteristics a 90° angle along stolons; alternate double rows oriented at about 180° from each other on stolons and nearly touching each other; no extra extensions (terminal processes) at the end of each stolon (past the last zooid row). Other similar bryozoans have different degrees of zooid spiraling around the stolon, usually greater than 100° (only 0-90° in A. alternata). Other bryozoans may also have more than 2 branches at each node (3 or 4), extensions Similar Species (terminal processes) at the end of each branch (past the last zooid), and zooid rows that are oriented approximately 30° from each other (about 180° in A. alternata) and are much further apart (not nearly touching). Habitat Gulf and bay, usually attached to a substrate, hardened or otherwise. Maximum Size 30 cm (12 in)

Sauerkraut bryozoan Page 314 Zoobotryon verticillatum Family Vesiculariidae - bryozoans

Colony of polyps; looks like sauerkraut, resembles an algal plant with many branches; color is off-white to light green, translucent to transparent; polyps Distinguishing and more detail cannot be seen with the naked eye; when stolon (main Characteristics branches) are squeezed, they collapse and become flaccid; each node on the stolon usually has 3 branches, but sometimes 2 or irregular branching. This bryozoan is similar in appearance and color to the red algae, Gracillaria, Similar Species but the red algae's body walls will not collapse when squeezed. Habitat Gulf and bay, found on hard substances or floating on surface in large masses Maximum Size unknown Other Common Names spaghetti bryozoan

Spiral-tufted bushy bryozoan Page 315 Bugula nertina Family Bugulidae - bryozoans

Colony of polyps; resemble a reddish seaweed, bushy branching tufts, grows upright; color reddish purple, purple brown or dark red; the following characteristics can be seen with the use of a magnifier or dissecting scope: individuals in the colony (called zooids) are enclosed in rigid cup-like structures called zooecia (sing. zooecium); branches in the colony have double rows of Distinguishing zooecia, all facing the same direction, zooecia are stacked one above the other Characteristics in each row; the rows are staggered so the tops of the zooecia come to about the middle of the zooecia in the other row; the zooecia have no spines on its outer edges although the outer corners are pointed; smooth white globular structures (called ovicells) sit atop the zooecia and contain the embryos of the colony. Other species of Bugula are white or tan, have spines or bird-head like Similar Species structures at the ends of the zooecia, and do not have the white globular ovicell structures. Red algae do not have zooids. Habitat Gulf and bay, attaches to hard structures Maximum Size bushy structure up to about 15 cm (6 in) in diameter Other Common Names brown bryozoan

Beroidae - Comb Jellies (Ctenophores) Page 316

Comb jellies are members of the phylum Ctenophora, pronounced "ten-o-for-a" (the "C" is silent). They are free-floating marine organisms that have roundish bodies made up of gelatinous tissue that contain 95% water. There is no head or tail, but there is a mouth and an anus. Instead of a brain, they have a network of nerves beneath the skin. What sets comb jellies apart from real jellies are the eight rows or sets of cilia that line the body. The cilia are their main mode of transportation. Some comb jellies have two retractable tentacles, but the tentacles to not have stinging cells. Comb jellies can range in size from several millimeters to 1.5 m (59 in). All are carnivorous and some can swallow organisms larger than themselves. Some (like Beroe species) eat only other comb jellies. They are hermaphroditic, possessing both male and females sexual organs, but their reproduction is sexual.

Most comb jellies give off bioluminescence, especially when disturbed. If you've ever seen the waves glow on the beach at night, it is probably due to a swarm of comb jellies.

Sea walnut Page 317 Beroe ovata Family Beroidae - comb jelly

Bell gelatinous, transparent, bell-shaped, flattened and wide at the oral end; not Distinguishing firm, very fragile; color pinkish to brownish; 8 rows of tiny cilia (short moving Characteristics hair-like structures) from top of bell to oral opening; no tentacles, doesn't sting. It's bell-shaped body flattened at the oral end and the radiating rows of cilia Similar Species distinguish this ctenophore. Habitat Gulf and bay Maximum Size 11.5 cm (4 1/2 in)

Page 318 Aequoreidae, Bougainvilliidae, Porpitidae, Physaliidae - Hydroids

Hydroids are colonial, plant-like organisms and are closely related to jellyfishes. Most hydroid life cycles consist of three stages: a flat, ciliated free-swimming larva (called a planula larva) that grows into a plant-like colony of polyps which, in turn, produces many free-swimming gelatinous medusae (jellyfish type body) by budding off the polyps. The polyp colony is considered to be in between the larval stage and the adult (medusa) stage. Some hydroids skip the polyp colony stage, and the larvae develop straight into medusa. Others reduce the medusa stage, and the colony continues to develop into the main adult form. Some of the colony forms are so small that it is extremely difficult to find them (as in the hydromedusa Nemopsis bachei whose colony stage reaches a mere 0.6 mm high). The colony stage of the many-ribbed jelly (Rhacostoma atlantica) is so rare it is yet to be described. The freshwater jellyfish, Craspedacusta sowerbyi, is a hydroid.

The colonies contain different types of polyps, each with a specific function. Some catch prey. Some eat and digest the prey. Some defend the colony, and some reproduce. Most have many small tentacles to catch and move food particles. The polyps are attached to a base stalk (stolen) which may be branched or unbranched. The polyp stages usually attach to hard substrates where as the medusa are mostly free- swimming. Most hydroid colonies are carnivorous as are the medusa. Both the polyps and the medusa can inflict sever stings in human.

Hydroid medusae are called hydromedusae to distinguish them from the true jellyfishes. The hydromedusae have a velum, which is a thin shelf of tissue encircling the underside of the medusa bell. The true jellyfishes lack a velum. Also, true jellyfishes do not go through a colonial polyp stage.

Page 319 Blue button Porpita porpita Family Porpitidae - hydroids

Colonial polyps consisting of a whitish to golden brown circular floating disk with up to 100 cocentric (circling) and radiating air chambers, chitinous, texture is like styrofoam; surface edges of disk with darker color (blue or green); edges Distinguishing of disk with attached blue or green tentacles (actually hydroid polyps), short, Characteristics medium and long; each tentacle has small branches starting about halfway down its length, each branch ends in a node of stinging cells; a mouth is located underneath its disk. Very similar to the by the wind sailor (Velella velella) but without the sail and Similar Species with longer tentacles. Habitat Gulf, floats on the surface Maximum Size disk up to 5 cm (2 in)

Page 320 By the wind sailor Velella velella Family Porpitidae - hydroids

Body made of flexible chitin (cellophane-like texture); color is aqua-green to blue to violet; base float is oval with concentric rings (representing air tubes) on Distinguishing the surface; above float is an erect, triangular "sail" projecting at an angle; Characteristics below the float around the edges are short tentacles; smaller tentacle-like objects on lower surface; in the center a small mass hangs down where the mouth opening is. Fairly unique; similar to the blue button Porpita porpita but P. porpita is more Similar Species round, usually green and has no sail. Habitat Gulf, floats on the surface Maximum Size 10.2 cm (4 in) long, 7.6 cm (3 in) wide and 5.1 cm (2 in) high.

Clinging jellyfish Page 321 Nemopsis bachei Family Bougainvilliidae - hydroid

Bell gelatinous, transparent, semi-spherical, somewhat firm; 4 flat ribbon-like gonads, united at the top, radiating down the sides of the bell to near the oral Distinguishing opening giving an X-like appearance from above, gonads are translucent with Characteristics whitish, pinkish or greenish color; 4 clusters of tentacles on margin of bell, usually can't be seen by the naked eye; does not sting. The appearance of the radiating gonads and 4 clusters of tentacles (need a Similar Species magnifier to see) distinguish this hydroid from other hydroids and ctenophores. Habitat Bay, pelagic Maximum Size 1.1 cm (1/2 in) Comments This is not a true jellyfish or a comb jelly. It is a hydroid.

Many-ribbed jellyfish Page 322 Rhacostoma atlanticum Family Aequoreidae - hydroid

Bell gelatinous, bowl-shaped, broader than deep; no color, translucent to Distinguishing transparent; has radiating canals that feel like ridges; rows of wart-like bumps Characteristics on underside of bell; center of bell has circular area smooth with no ridges; tentacles very fine, small, do not sting. Similar to another hydrozoan, Aequoria, which does not have the warty bumps Similar Species and is smaller in size. Habitat Gulf, pelagic Maximum Size 40 cm (15 3/4 in) bell diameter Other Common Names crystal jelly, water jelly Comments This is not a true jellyfish. It's actually a hydroid.

Portuguese man o' war Page 323 Physalia physalis Family Physaliidae - hydroid

Colony of 4 types of polyps: 1) the air bladder is translucent, balloon-like, one end wider than the other; back with raised, compressed air canals (sail); colors range from blue, purple, pink, to green; stays on surface of water, acts as a sail; Distinguishing 2) long, string-like tentacles under air bladder, dark green or purple, covered Characteristics with stinging cells; 3&4) digestive and reproductive polyps form clusters of short, stringy masses that dangle beneath the air bladder, colors the same as tentacles. Another Physalia, P. utriculus, lives in the Pacific Ocean. It is distinguished Similar Species from P. physalia by having a shorter float (6 in) and only 1 long stinging tentacle. Habitat Gulf, ocean surface Maximum Size float up to 30 cm (12 in), tentacles up to 50 m (164 ft), typically 10 m (33 ft) Not a true jellyfish. Venomous. Stinging cells can cause very painful welts. Comments Fatalities have been reported due to the Portuguese man o' war.

Page 324 Rhizangiidae, Caryophylliidae, and Oculinidae - Hard corals

Hard corals, also called stony corals, are in the Order Scleractinia. Most are colonial polyps that are housed in a solid calcareous skeleton (similar to an apartment building with many tenants). The polyps secrete a calcareous cup-like structure, the corallite, around itself for protection. The corallites are usually joined to each other by a calcareous material called the coenosteum. Many hard corals build massive reefs, but some build smaller structures or are encrusting (growing on other hard objects). A few form large individual polyps. Hard corals feed by extending their polyps to capture food from the water column, though many corals get most of their energy from tiny microscopic algae (called zooxanthellae) that live within the polyp's tissue. Zooxanthellae are also responsible for the beautiful colors exhibited by corals, colors ranging from orange, yellow, green, blue, red and purple. These corals can expel their zooxanthellae when under stress producing a phenomena called "coral bleaching". Generally, non-reef-building corals lack zooxanthellae while reef builders possess numerous in their tissue. Because of the light requirement of the zooxanthellae, most reef-building corals are limited to shallow depths (<50 m) and clear water.

Within the colonies, reproduction is asexual. Polyps reproduce by budding off a part of its body which develops into a new polyp. The new polyps stay with the colony and extend the colony's size. Sexual reproduction may also occur where sperm and eggs are "broadcast" into the water, and the sperm fertilizes the egg in the water column. These new polyps, called planulae, can swim or crawl and generally initiate a new colony.

There are 29 families of scleractinians. Corals of the family Rhizangiidae are non-reef builders. They form small, encrusting colonies of corallites joined at their bases. Their septa (skeletal radiating plates in the corallites) are not fused together and are dentate. They are a shallow water species.

The family Caryophylliidae are encrusting corals that are knob-like in appearance. They may be colonial or solitary. Some of the solitary species are free-living, unattached to hard substrates. Most caryophyllids lack zooxanthellae, thus lacking the brilliant colors of some other coral families. All have a fine external membranous layer, called the epitheca, surrounding the corallites. The corallites of some of the solitary species are among the most beautiful designs in nature, the septa usually displaying a symmetry in multiples of six.

The family Oculinidae are colonial corals that can be encrusting or branching and form a multitude of shapes such as bushes, columns, flat structures or domes. The corallites are widely space and connected by a smooth skeletal wall (coenosteum). The walls of the corallites are smooth but may have small costae (ridges) at the top rims. Their septa extend upward and outward, giving the corallites a spiky appearance, which is characteristic of the family. Diffuse ivory bush coral Page 325 Oculina diffusa Family Oculinidae - coral

Colonial polyps, branching, forming cup-like structures (corallites) that are widely space (except for possibly at the tip) and are broadly joined together in branching stalks; color yellow brown (live); corallites 3-4 mm (0.1-0.15 in) in Distinguishing diameter, short, radiating plates (septa) inside corallites numerous, minutely Characteristics beaded, extending above the corallite wall giving a spiky appearance; outer walls and coenosteum (skeletal material between walls of corallites) smooth, not ridged; branches thin (< 1.5 cm or 1/2 in in diameter), short, crooked, closely spaced together, bush-like in appearance. Other Oculina species have thicker, longer branches and/or the corallites Similar Species extend prominently from the branches. Habitat Gulf and bay, shallow water areas of high sedimentation Maximum Size colony up to 30.5 cm (12 in) in diameter

Hidden cup coral Page 326 Phyllangia americana Family Caryophylliidae - coral

Colonial polyps forming singular, cup-like structures (corallites), sometimes joined at the bases or between cups with a calcium carbonite skeletal layer (the coenosteum); color light brown (sometimes yellowish brown to reddish brown) Distinguishing within and on upper corallites, lower corallites and coenosteum white; corallites Characteristics circular, usually ridged on the outside, central pits deep; septa (radiating plates inside corallite) arranged with 6 primary plates, 6 smaller ones and smaller ones in between those; live polyp with clear warty tentacles; encrusting (grows on other structures), non-reef forming. The speckled cup coral, Rhizosmilia maculata, has 12 large septa (6 in the Similar Species hidden cup coral) and live polyps have a speckled pattern. The hidden cup coral's brown color helps distinguish it from other cup corals. Habitat Gulf and bay, attaches to hard substrates, jetties, pilings, shell Maximum Size corallites up to 1.5 cm (1/2 in)

Northern cup coral Page 327 Astrangia poculata Family Rhizangiidae - coral

Colonial polyps arranged in clumps of cup-like structures (corallites); live polyps are translucent to brown, with numerous tentacles, appear fuzzy looking; skeleton yellowish to white; corallites are tightly packed, circular, can be up to 10 mm (0.4 in) but usually not more than 5 mm (0.2 in) in diameter; Distinguishing inside cups are skeletal radiating plates (septa), septa are irregularly beaded, Characteristics usually 24 in number; cups may be touching each other or slightly separated; skeletal material between cups (coenosteum) present, cups raise above coenosteum with definite walls; small ridges on outside of cup (called costae, are extensions of the inside septa) with granulated margins; encrusting (grows on other structures), non-reef forming. The southern cup coral, A. solitaria may be clumped but the cups grow separately (coenosteum between cups rarely present). Cups are small (=<6 Similar Species mm or <1/3 in) on extended columns. Their septa are usually 36 in number (up to 48). Habitat Gulf and bay, attaches to hard substrates, jetties, pilings, oyster shell Maximum Size corallites up to 1 cm (0.4 in) in diameter, usually 5 mm (0.2 in) or less Other Common Names northern star coral, false coral Previous Scientific A. danae, A. astreiformis Names Comments This is the coral commonly seen on oyster shells in the bays.

Mastigiidae, Ulmaridae, Pelagiidae, Chiropsalmidae, Page 328 Rhizostomatidae - Jellyfishes

True jellyfishes belong to the phylum Cnidaria, pronounce "ni-dare-ee-a" (the "C" is silent). Their translucent free-floating bodies are usually bowl-shaped, semi-circular or squarish in shape. They are gelatinous and contain about 90% water. The main body is usually called a "bell", "medusa" or "umbrella". Jellyfishes have no brain, heart, bones, eyes, etc. They basically have a mouth and anus, four stomachs, gonads, and a nerve network. From the underside of the bell extends four to eight oral arms or flaps which are used to capture their prey. Tentacles with stinging cells (cnidocysts or neumatocysts) usually extend from the margin of the bell. They swim by opening and closing their bell. The largest jellyfish, the lion's mane, can be up to 2.1 m (7 ft) wide with tentacles as long as 40 m (130 ft). The deadliest jellyfish, the sea wasp, has killed more people than any other marine organism.

Some countries consider jellyfishes a delicacy.

Australian spotted jellyfish Page 329 Phyllorhiza punctata Family Mastigiidae - jellyfish

Bell gelatinous, semi-spherical, 1/2 high as broad; bell covered with white Distinguishing spots; 8 clumps of oral arms hang from the underside of the bell; transparent Characteristics ribbon-like appendages hang from the oral arms; no long thin tentacles; sting is mild. Similar Species The white spots give it away. Habitat Gulf and bay Maximum Size 62 cm (24 1/2 in) bell diameter

Cannonball jellyfish Page 330 Stomolophus meleagris Family Rhizostomatidae - jellyfish

Bell rounded, ball-shaped, translucent, rigid, gelatinous; color whitish, milky, Distinguishing sometimes bottom of bell rimmed in brown pigment; rigid stalk extends from Characteristics beneath the bell; attached to the end of stalk is a cluster of finger-like "oral arms" surrounding a mouth; no tentacles. There are no other local species with a rigid, rounded bell like the cannonball jellyfish. An invasive species, the Australian spotted jellyfish (Physalia Similar Species physalis), which has been caught in the northern Gulf coast and in Galveston Bay, has a round bell, especially in juveniles. They can be distinguished from the cannonballs by the whitish spots on its bell. Habitat Gulf and bay, floats near the surface Maximum Size 25 cm (10 in) Other Common Names cabbagehead, jellyball Although the cabbagehead has no tentacles, it does have stinging cells inside Comments its bell. The sting from a cabbagehead is very mild. These creatures can swim very fast.

Moon jellyfish Page 331 Aurelia aurita Family Ulmaridae - jellyfish

Bell gelatinous, bowl-shaped, broader than deep; sometimes with light radiating stripes, 4 oval-shaped gonads in a cloverleaf formation can be seen through Distinguishing the bell; short thread-like tentacles around the edge of the bell; the bell is Characteristics slightly indented in 8 spots; 4 long ribbon-like oral arms hang beneath the bell, at right angles to each other; sting is mild. Similar Species The 4 clover-shaped gonads distinguish this jelly from others. Habitat Gulf and bay Maximum Size 40 cm (15 3/4 in) bell diameter

Mushroom jellyfish Page 332 Rhopilema verrilli Family Rhizostomatidae - jellyfish

Bell gelatinous, round, mushroom-shaped when swimming, translucent; bell may be creamy white to light yellow, brown, blue, pink or green, sometimes Distinguishing with very light brown pigment close to margins of bell; pinkish to brown center Characteristics (from organs underneath); no tentacles; underneath bell are 8 oral arms with fingers, brownish tinges on ends; digestive glands underneath bell pinkish, jumbled; 16 radial canals in bell (mantle); edges of bell with lappets (lobes). The mushroom jelly is similar to the cannonball jellyfish, which also has no tentacles. The mushroom jelly is much flatter and softer, lacks the dark brown Similar Species bands sometimes associated with the cannonball and grows larger than the cannonball (up to 51 cm or 20 inches in diameter, 25 cm or 10 inches in the cannonball). Habitat Gulf mostly, sometimes occurs inshore near the mouth of bays Maximum Size 51 cm (20 in) in bell diameter Other Common Names mushroom cap jellyfish, sea mushroom jellyfish Although the mushroom and cabbagehead jellies have no stinging tentacles, they still have stinging cells within their bells and can produce mild stings to Comments humans. Both jellyfishes are considered delicacies in Japan and are eaten raw or pickled.

Purple-striped jellyfish Page 333 Pelagia noctiluca Family Pelagiidae - jellyfish

Bell gelatinous, semi-spherical; pink to purple spots on bell and oral arms when Distinguishing alive; pink to purple ribbon-shaped gonads can be seen through bell; 4 Characteristics scalloped oral arms hang below bell; 8 long thin tentacles originating from margin of bell; sting is moderate to severe. Similar Species The pink to purple color distinguishes this jelly from others. Habitat Gulf, pelagic Maximum Size 12 cm (4 3/4 in) Other Common Names mauve stinger

Sea nettle Page 334 Chrysaora quinquechirrha Family Pelagiidae - jellyfish

Bell gelatinous, bowl-shaped, broader than deep; color is translucent to opaque white, usually has small white spots and radiating reddish brown stripes; the Distinguishing bell is slightly indented (notched) in 8 spots, 1 long tentacle emerges from each Characteristics notch, several shorter tentacles emerge from between the notches, 24-40 tentacles in all; 4 long convoluted oral arms hang beneath the bell; sting is moderate to severe. Similar Species The radiating brown stripes distinguish this jelly from others. Habitat Gulf and bay Maximum Size 25 cm (10 in) Previous Scientific C. quinquecirrha, Dactylometra quinquecirrha Names

Sea wasp Page 335 Chiropsalmus quadrumanus Family Chiropsalmidae - jellyfish

Bell gelatinous, about the size of a fist, cube-shaped, flat on top, transparent; 4 Distinguishing muscular, hand-shaped fleshy pads (pedalia) hang from bottom of the bell, Characteristics each with 7-9 fingers; each finger gives rise to a long (3-4 m or 9.8 to 13 ft), stinging tentacle; wart-like stinging bumps on the bell. Box jellies are easy to distinguish from other jellies by their cube-shaped bell and the 4 pedalia (group of fleshy finger-like pads) that hang down from the Similar Species bottom of the bell. Sea wasps differ from other box jellies found in the Gulf of Mexico by having only 1 tentacle per extensions ("fingers") of their pedalia. Other box jellies have multiple tentacles from each extension. Habitat Gulf and bay, open waters Maximum Size 15 cm (6 in) width and height of bell Other Common Names box jellyfish, four-handed box jellyfish Extremely venomous, has been known to kill people within minutes of being Comments stung.

Squillidae and Lysiosquillidae - Mantis Shrimps Page 336

Mantis shrimps are not shrimps. They get their name from their appearance which looks like cross between a praying mantis and a shrimp. Their bodies are elongate, more lobster-like than shrimp-like. Many have spines on their carapace. Their claws are more like folded spears with several teeth or spiny projections. These powerful claws are used to spear, stun or dismember their prey. Most are nocturnal, being more active at night. They spend most of their time in intricate burrows or in rock formations, leaving only to feed. They are very aggressive and will actually chase or hunt their live prey. When caught, they flip their abdomen and heads in order to hurt or maim their captor. Fishermen who catch them in their nets refer to them as "thumb splitters".

Dark-banded mantis shrimp Page 337 Lysiosquilla scabricauda Family Lysiosquillidae - stomatopod (crustacean)

Body more lobster-like than shrimp-like; carapace and body rigid; carapace translucent, body and carapace cream-colored, dark brown bars on anterior portion of segments, segments whitish laterally, uropods (tail fans) with black pigment; telson (hard part of tail fan) with dark blotches; telson broader than Distinguishing long with a raised medium hump, spines on margins; margins of last 2 Characteristics abdominal segments armed with spines; claws comb-like, no movable finger, fold in towards arms; claws with 8-11 teeth (usually 9-10); eyes T-shaped, cornea bi-lobed; last segment of last 3 walking legs oval in shape; small spine on 5th thoracic segment (i.e., 1st abdominal segment behind carapace). Similar Species The dark banding on the abdomen distinguishes this mantis shrimp. Habitat Gulf and bay, sandy or muddy bottoms Maximum Size 27.5 cm (11 in) Other Common Names sea locusts, thumb splitters

Lesser mantis shrimp Page 338 Gibbesia neglecta Family Squillidae - stomatopod (crustacean)

Body more lobster-like than shrimp-like; carapace and body rigid; carapace and body light brown, dark pigments separate some of the segments, no dark bar on 2nd abdominal segment; last segment of outer uropods (tail fans) with Distinguishing dark pigment and light yellow laterally; telson (hard middle part of tail fan) with Characteristics spines on margins; claws comb-like, no movable finger, fold in towards arms; claws with 5 teeth; cornea of eyes set at angle to stalk; spatulate lateral spine on 5th thoracic segment (i.e., 1st abdominal segment behind carapace). The lack of a dark bar on the 2nd abdominal segment, five teeth on the claw, Similar Species and the spatulate lateral spine on the 5th thoracic segment distinguished this mantis shrimp from others. Habitat Gulf and bay, sandy or muddy bottoms Maximum Size unknown Other Common Names sea locusts, thumb splitters

Mantis shrimp Page 339 Squilla empusa Family Squillidae - stomatopod (crustacean)

Body more lobster-like than shrimp-like; carapace and body rigid; carapace translucent, light colored; body light brown, dark pigments separate segments, dark bar on 2nd abdominal segment; uropods (tail fan) with dark pigment and Distinguishing deep yellow tips; telson (hard middle part of tail fan) with spines on margins; Characteristics claws comb-like, no movable finger, fold in towards arms; claws with 6 teeth; cornea of eyes set at angle to stalk; anteriorly curved lateral spine on 5th thoracic segment (i.e., 1st abdominal segment behind carapace). The dark bar on the 2nd abdominal segment, the deep yellow pigment on the Similar Species tail fans, 6 teeth on the claws, and curved lateral spines on the 5th abdominal segment distinguish this mantis shrimp. Habitat Gulf Maximum Size 18.5 cm (7 1/4 in) Other Common Names sea locusts, thumb splitters

Offshore mantis shrimp Page 340 Squilla chydaea Family Squillidae - stomatopod (crustacean)

Body more lobster-like than shrimp-like; carapace and body rigid; carapace translucent, light colored; body yellowish light brown, dark pigments separate segments, bar on 2nd abdominal segment reddish with dark ends; uropods (tail Distinguishing fans) with little pigment; telson (hard middle part of telson) with 2 dark crescent- Characteristics shaped spots with reddish color on anterior part; telson with spines on margins; claws comb-like, no movable finger, fold in towards arms; claws with 6 teeth; cornea of eyes set at angle to stalk; anteriorly curved lateral spine on 5th thoracic segment (i.e., 1st abdominal segment behind carapace). Similar Species The 2 crescent-shaped spots on the telson distinguish this mantis shrimp. Habitat Gulf Maximum Size 13 cm (5 in) Other Common Names sea locusts, thumb splitters

Page 341 Ancinidae - Marine isopods

Ancinidae is one of the many families of marine isopods. They are somewhat related to terrestrial isopods, the most notable of which is the pill bug or roly-poly. Isopods are not insects. They differ by having 2 pair of antennae instead of 1 as in insects and by having some legs that branch. Like insects, isopods have 3 main body regions: the head, thorax and abdomen. Unlike most insects, the 3 parts are usually fused and may not be easily distinguished, especially when looking from above. Marine isopods breathe through gas exchange from the gills on their abdominal legs. When they reproduce, the female broods the eggs in a pouch, called a marsupium, located under the body. There is no larval stage. The eggs develop directly into miniature adults.

Sizes of marine isopods range from 1 mm (.04 in) to 360 mm (14.2 in) though very few exceed 50 mm (2 in) and most are 3-20 mm (less than 1 in). Their homes range from the intertidal zones on beaches to the greatest depths of the ocean (7280 m or about 24,000 ft). The largest marine isopod is the giant isopod, Bathynomus giganteus, which lives in the cold, deep waters of the sea. The shallow water varieties take refuge in various places like sand, crevices, dead shells, worm tubes, algal mats, dead wood and even in living organisms. Most are benthic (live on the bottom) and are detritus feeders or filter feeders. Some though are carnivores or parasites. The tongue-eating isopod, Cymothoa exigua, feeds on the tongues of fishes and eventually takes the place of the tongue.

In all, there about 6,250 species of marine isopods worldwide.

Page 342 Thorn isopod Ancinus depressus Family Ancinidae - marine isopods

Small, oval, depressed, twice as long as wide; color white or cream; body with a hard calcified exoskeleton; head short, rounded lateral edges, 2 eyespots; 2 pair segmented antennae; thorax (upper body) segmented crosswise, lateral sides angled downward; abdomen (lower part) with 2 segments, 1st mostly or Distinguishing entirely hidden under last thorax segment, terminal segment triangular, truncate Characteristics at point, curled inward on underside; legs on underside segmented, fold inward, 1st pair of legs subchelate, i.e. 2nd to last segment a circular disk; last segment is a half claw folding in on circular disc; 2nd pair of legs unbranched on tips, rest of legs branched on terminal segment; uropods (the extensions on the last abdominal segment) unsegmented, unbranched, long and tapering. The thorn isopod can be distinguished by its downward angled laterals on the Similar Species segments and by its long, unbranched, tapering uropods. Habitat Gulf, intertidal zone and shallow sandy waters, buries in the sand Maximum Size 1.2 cm (1/2 in) Other Common Names flat pill bug May look like a terrestrial pill bug. The thorn isopod can roll itself into a ball and Comments lock its head into the grooves on the underside of the abdomen. Special thanks to Ashley Wiseman, TAMUG student, for collecting the critter. Piscicolidae and Ozobranchidae - Marine Leeches Page 343

Marine leeches are blood-sucking parasites that feed on marine turtles (family Ozobranchidae) or fishes (family Piscicolidae). Turtle leeches spend their entire life cycle attached to the turtle. During heavy infestations, the turtle may be harmed due to enormous blood loss. Fish leeches are temporary parasites that leave their hosts after one or a few meals. Some take shelter amid seagrasses or rocks and may attach themselves to crustaceans until they are ready for their next meal. Others only leave their hosts to lay their eggs and then quickly find another host. Some fish leeches attach only to a single species of fish. Others are not so picky and will attach to a variety of fishes. There are only a handful of marine leech species found in the Gulf of Mexico (about 9).

Marine leech Page 344 Calliobdella vivida Family Piscicolidae - marine leeches

Body cylindrical, worm-like; with brownish transverse globular bands; suckers on both ends; caudal (tail end) sucker large, distinct from body, about equal to Distinguishing the maximum width of the body; anterior end narrower than tail end, oral Characteristics sucker (anterior end) small but distinct from body by a constriction, has 2 pair of eyespots; body smooth, no branching extensions (papillae) or bumps (tubercles). Can be distinguished from other marine leeches found in the Gulf of Mexico area by having no branching extensions, no warty appearance, a large caudal Similar Species sucker, more than 1 pair of eyespots on oral sucker, and a distinct pattern of pigmentation. Habitat Gulf and bay, parasitic Maximum Size 2.9 cm (1 in) This is a common parasite of fishes, such as flounder and croaker, and the blue Comments crab. Occurs mainly in winter and spring months.

Page 345 Mellitidae - Sand Dollars

Sand dollars, or keyhole urchins, are members of the Phylum Echinodermata, which also includes starfishes and brittle stars, sea urchins, sea cucumbers, and feather stars. Sand dollars are round, flat and rigid with no arms. Like starfishes and brittlestars, they have no anterior, posterior, head or tail. Adult sand dollars have five oval-shaped holes that go all the way through the body. The top surface also has five pairs of pores called petalloids. The pairs are arranged in the shape of a five-petal flower. Within the petalloids are specialized tube feet that are used for respiration.

When live, sand dollar bodies are covered with small spines, and they are usually green, brown, tan or gray in color. After death, their spines fall off exposing their off-white skeletons. This is how they are usually found washed ashore on beaches. Their mouth, on the underside of body, has a set of five jaws with teeth. The arrangement of the jaws is called "Aristotle's lantern", which is also common in most sea urchins. Beachcombers who find the jaws from broken sand dollars often refer to them as "doves" because they resemble a bird in flight.

Sand dollar Page 346 Mellita quinquiesperforata Family Mellitidae - sand dollar

Body round, flat with an upward slope towards the center, rigid; no arms; color usually green but can be tan, brown or gray; body covered with short spines; bottom side flat with mouth in the center and anus to the side; mouth with 5 jaws with teeth arranged in a circle (called Aristotle's lantern); bottom with tube Distinguishing feet; top with specialized tube feet, called petalloids, each with 2 rows of pores Characteristics arranged in the shape of a 5-petal flower; 5 oval-shaped holes (lunules) through skeleton, 1 pair near the top, 1 pair near the bottom and 1 large hole between bottom pair (young may not have 5 holes yet, notches mark where lunules will eventually develop). This is the only species of sand dollar found off Texas.. Another species, M. Similar Species tenuis, occurs in the Gulf of Mexico but is limited to east of the Mississippi River. It has much smaller spines than our sand dollar. Habitat Gulf, shallow waters, bury in sandy bottoms Maximum Size 15 cm (6 in) diameter, common to 7.5 cm (3 in) Other Common Names keyhole urchin

Page 347 Actinostolidae, Hormathiidae and Actiniidae - Sea Anemones

Sea anemones are individual, sessile polyps with cylindrical-shaped bodies. At one end is the oral disk and mouth surrounded by many tentacles, which usually contain stinging cells. The other end is the base used to attach to hard substances. They come in all shapes, colors and sizes. Many are brilliantly colored. Most are small, less than 3.8 cm (1.5 in) in diameter. However, the largest anemone can reach up to 2 m (6.5 ft). When disturbed or threatened, anemones can withdraw their tentacles inside their bodies and basically close themselves in. They are known to form symbiotic relationships with many organisms, including clownfishes, shrimps and crabs. These organisms live within the tentacles of the anemones (without getting stung) or the anemone attaches to the organisms (as with crabs). Either way the anemone's tentacles provide for protection. In return, the anemones eat small particles left over from the organism's feeding.

Onion anemone Page 348 Paranthus rapiformis Family Actinostolidae - anemone

Body soft, translucent; color pink to cream, reddish brown to greenish gray, has light longitudinal stripes; when closed, body is round, resembling a "cocktail Distinguishing onion"; body can elongate greatly sometimes looking worm-like; base Characteristics sometimes flares out into a bulb-like shape; tentacles colorless to light brown, translucent. The "cocktail onion" shape with the longitudinal stripes help distinguish this Similar Species species. Habitat Gulf, usually burrows in the sediment with tentacles above surface of sediment Maximum Size medium size anemone, can extend up to 35 cm (13 3/4 in) or more. Other Common Names sea onion

Tricolor anemone Page 349 Calliactis tricolor Family Hormathiidae - anemone

Body soft, cylindrical with tentacles around the top, base attaches to hard substrate; color beige to dark brown with beige streaks to dark orange and red or purple; has dark spots (pores) surrounding the basal margin; tentacles are Distinguishing short, usually whitish, but may be dark orange or pink; pigment around the Characteristics mouth and oral disk tricolored, usually with a darker outer ring and orange and/or pinkish center; releases orange stringy filaments (acontia) from the oral disk and from the dark pores at the base when disturbed. This anemone varies in color but will always have the dark spots around the Similar Species basal margin. Gulf, usually found on shells occupied by hermit crabs or attached to the calico Habitat box crab Maximum Size 5 cm (2 in) disk width Other Common Names hermit anemone, hitchhiking anemone, cloak anemone Previous Scientific Actinia bicolor; Actinia tricolor; Adamsia bicolor; Adamsia egletes; Adamsia Names tricolor; Calliactis egletes; Cereus bicolor

Warty anemone Page 350 Bunodosoma cavernatum Family Actiniidae - anemone

Body soft, translucent, columnar when stretched; color brownish or tannish; Distinguishing vertical rows of pale, dusky or sometimes blue bumps on column; tentacles Characteristics numerous, short, sometimes marked with red stripes near mouth; sometimes with white bumps (acrorhagi) at the base of the tentacles. This is a very common anemone and is easily recognized by its warty Similar Species appearance. Gulf, attached to jetties or buried in the sand on the beach at low tide, Habitat occasionally found on the backs of hermit crab shells Maximum Size 9 cm (3 1/2 in) in height, 5 cm (2 in) in diameter of oral disk (mouth) Previous Scientific B. cavernata Names

Page 351 Phyllophoridae and Synaptidae- Sea Cucumbers

Sea cucumbers are members of the Phylum Echinodermata, which also includes starfishes and brittle stars, sea urchins, sand dollars and feather stars. They have elongate cylindrical bodies with a mouth at one end and an anus at the other. They differ from other echinoderms by having bilateral symmetry instead of a 5- sided symmetry. The oral end of the body is usually surrounded by tentacles. The skin may be leathery or soft, and is often covered with protrusions called tube feet. Their internal skeletons are reduced to microscopic "ossicles" made of calcium that are imbedded in their tissue. Ossicles come in a variety of odd shapes ("tables", "rods", "baskets", "anchors", "buttons", "cups") and are used to distinguish between species. A unique feature of many sea cucumbers is that, when disturbed, they will expel all or part of their guts out through the anus to distract predators. The guts later regenerate.

The respiratory organs of sea cucumbers are located in their anus. They breathe through gas exchange by drawing in and expelling water through their anus. The respiratory organs also double as the excretory organs, expelling waste from the body.

Sea cucumber Page 352 Allothyone mexicana Family Phyllophoridae - sea cucumber

Body elongate, cylindrical, larger ones more U-shaped; covered with short, hard protrusions called "tube feet"; tube feet cover entire body (except in very small individuals), arranged in indistinct radial lines; color tan to brown on tube feet; skin visible when inflated, translucent, color gray, bluish or slightly purple; Distinguishing oral end with 10 short, branched tentacles, 2 of which are very small, can Characteristics retract tentacles to inside of body; the calcareous ring (calcified plates surrounding the esophagus) with long posterior projections, made of mosaic pieces; ossicles "table" shaped, disk surface with many holes, margins knobbed, 4 extended pillars, in large specimens the pillars may conceal the holes and knobbed margins; ossicles of the tube feet with curved disk. Sea cucumbers are distinguished by their body shape, the arrangements or lack of their tube feet, the number and shape of their tentacles, the shape of Similar Species their calcareous ring, and the shape of their ossicles (which can only be seen under magnification). Many are brightly colored. This one is not. This sea cucumber is common in and around grass flats. Habitat Gulf and bay, common in grass flats Maximum Size 20 cm (8 in) Comments No common name for this sea cucumber.

Page 353 Beneden's sea cucumber Protankyra benedeni Family Synaptidae - sea cucumbers

Body elongate, cylindrical, worm-like; body color off-white to light pink; body wall somewhat translucent with transverse lines, longitudinal muscle bands are visible, lighter in color; no tube feet on body (seen under magnification); 12 tentacles on oral end, simple, not divided; in the flesh are "ossicles" or "spicules" in the shape of anchors and anchor plates (see photos); anchors are Distinguishing unbranched with 0 to 11 small teeth on each extension, the feet of the anchors are slightly Characteristics upturned on the ends and finely serrated; the anchor plates have numerous oval holes, smaller ones near the edges, with 0 to about 6 teeth inside, little extension at one end to hold the anchors; both are similar in size fthroughout body and are about 1/2 millimeter long; also contains "miliary granules" which are minute rods with rounded ends and constricted in the middle. Sea cucumbers are distinguished by their body shape, the arrangements or lack of their tube feet, the number and shape of their tentacles, the shape of their calcareous ring, and the shape of their Similar Species ossicles (which can only be seen under magnification). Many are brightly colored. This sea cucumber is unccommon, found in offshore shallow waters (0-65 ft) in sandy and muddy bottoms. Habitat Gulf, sandy and muddy areas, approx. 0-20 m (0-65 ft) in depth Maximum Size avg 8-15 cm (3-6 in), can stretch much longer No official common name for this sea cucumber. The tiny anchors in the flesh cause it to "stick" to Comments objects, like fingers and hands, when touched.

Virgulariidae and Renillidae - Sea Pens Page 354

Sea pens (which include sea pansies) are not just one animal. They are a colony of small minute organisms called polyps or zooids. They consist of a body or common tissue mass, called the rachis, which the polyps attach to. The rachis can be long and thin to flat and round. The polyps develop a division of labor among themselves for feeding, reproduction and water circulation. One polyp usually develops into a stalk, called the peduncle, which is used to anchor into the substrate of sand or mud. They can disappear completely into the substrate and then re-emerge after a disturbance has passed. Many are beautifully colored, and when inflated, they can be twice as big as they are when deflated. Many give off bioluminescence when disturbed. Sea pens are related to corals and are usually termed "soft corals". Sea anemones, hydroids and jellyfishes are in the same phylum.

Pipe cleaner sea pen Page 355 Virgularia presbytes Family Virgulariidae - sea pen

Colony of polyps, long rigid narrow like a pen; tubular polyps form 2 rows of fleshy "leaves" that overlap on the ventral side and are fused together at the base of the leaves; leaves are attached to a shaft (rachis); on the dorsal side Distinguishing leaves do not touch; on dorsal side, shaft is bare with a groove down the Characteristics center; pen narrows at the upper tip; at lower end leaves stop, shaft continues into a stalk (peduncle) for attaching to objects; stalk usually missing on collected specimens. Most other sea pens have branches instead of leaves, are feather-like and/or are not rigid like this sea pen. Other narrow rigid sea pens with leaves have Similar Species small fan-like spines supporting the leaves and is rough to the touch. This sea pen is smooth. Habitat Gulf, soft bottoms Maximum Size unknown Comments Is a major portion of the diet of loggerhead sea turtles off Texas.

Sea pansy Page 356 Renilla muelleri Family Renillidae - sea pen

Colony of polyps, looks similar to a lily pad in shape; rachis (body) is flattened but fleshy, kidney or horseshoe shaped, convoluted, wider than long; has a Distinguishing single polyp which forms an anchoring stem (peduncle) on the underside, the Characteristics stem is shorter than 1/2 the diameter of the rachis; color usually reddish purple but can be from white to deep purple; upper surface with protruding polyps. Similar Species This is the only sea pansy in the Gulf of Mexico. Habitat Gulf, sandy bottoms Maximum Size 10 cm (4 in)

Gorgoniidae - Soft corals Page 357

Gorgoniidae belong to the Order Alcyonacea which are corals that lack a hard calcium carbonate skeleton, thus the name soft corals. Instead they have tiny spine-like harden parts in their bodies called sclerites (or spicules) that give them some degree of support. Like hard corals, these animals form colonies of tiny tentacled polyps attached to a harder surface. Colonies may be branch-like, fan-like, bushy or encrusting. Alcyonaceans includes sea whips, sea rods, feather plumes and sea fans.

The family Gorgoniidae includes soft corals whose sclerites are <0.3 mm in length. The colonies are arranged in a branch or stem-like shape with a central core. The core is made of a protein called gorgonin which is exclusive to the gorgonians and contain significant amounts of iodine and bromine. The polyps are embedded in a gelatinous material (called the coenenchyme) which surrounds the core. The material surrounding the openings in the coenenchymes (from which the polyps emerge) are called calyces (singular calyx). They may be flush with the surface or raised. The colonies may be attached to a hard surface by a holdfast or may float freely unattached. The morphology (i.e. shape, branching, attachment method) of the colony and shape of the sclerites are used to distinguish between species.

Sea whip Page 352 Leptogorgia setacea Family Gorgoniidae - coral

Colonial polyps arranged in whip-like colonies, long, thin, string or rope-like, diameter to about 4 mm (0.15 in), length up to 2 m (6.5 ft); color yellow or purplish; usually unbranched; unattached or attached to a small shell or other Distinguishing solid object usually by a narrow tuft; the center core of the colonies is a dark Characteristics wire-like axial rod (usually only seen in dead specimens); calyces (the cavity that surrounds the polyp) may be raised or flush, arranged in singular or multiple rows along the sides. The other sea whip in our area, L. virgulata, is moderately branched and Similar Species attaches by a basal plate. It is usually found attached to jetties. Habitat Gulf and bays Maximum Size up to 2 m (6 1/2 ft) Sometimes washes ashore in great tangled masses. May be mistaken for Comments yellowish rope.

Page 353 Luidiidae, Amphiuridae, Ophiactidae, Ophiuridae and Astropectinidae - Starfishes and Brittle Stars

Starfishes and brittle stars are members of the Phylum Echinodermata, which also includes sea urchins, sea cucumbers, sand dollars and feather stars. Both possess five-sided symmetry in which they are arranged in five parts around a central access. There is no anterior, posterior, head or tail. Some starfish and feather stars have a symmetry that is based on multiples of five, for example the starfish, Helicoilaster, which may have up to 50 arms and the sea lily, Comanthina schlegelii, which has 200 arms.

Starfishes and brittle stars have a skeleton made of calcareous plates, giving it an internal modular construction. The skin holds the skeleton together and contains pigment cells, receptor cells and sometimes gland cells which can secrete sticky fluids or toxins. The pigment cells can contain many vivid colors, and sometimes the colors can change quickly due to changes in light level. They also have many small tube feet, which are controlled by their vascular system. The tube feet have many functions including locomotion, wafting or moving food particles to their mouths, and aiding in respiration. Starfishes and brittle stars have two gonads in each arm whereas in sea urchins and sea cucumbers, the gonads take up the entire body cavity.

Starfishes are usually flattened with five (sometimes more) radial arms. The mouth is located on the central underside of the starfish, and the anus is located on top. Tube feet are located in a groove on the underside of each arm that runs from the mouth to the tip.

Brittle stars consist of a flat central disk with five or more long thin radiating arms. The arms are often spiny and move by undulations like a snake. At the beginning of each arm, there are usually paired scales called radial shields. As with starfishes, the mouth is on the underside of the disk and the anus is on top.

Starfishes and brittle stars are fragile and easily give up an arm or two to escape predation or danger. Most echinoderms have tremendous powers of regeneration. Many are capable of replacing lost arms or spines, and sometimes lost arms have been known to regenerate into a completely new body. Banded brittle star Page 354 Hemipholis elongata Family Ophiactidae - brittle star

Disk with 5 lobes; 5 narrow arms distinctly set off from disk in between lobes; arm segments with 3 spines on each side; 5 pair of plates (radial shields) on Distinguishing dorsal disk, almost heart-shaped; color gray to brown with dark banding on Characteristics arms, disk with mottling color; dorsal side of disk has no scales; tube feet on the ventral surface of arms are red. Red tube feet help distinguish this brittle star. Another brittle star has red tube Similar Species feet but has 6 arms instead of 5. Habitat Gulf, sandy bottoms Maximum Size 10 cm (4 in) arm span

Brittle star Page 355 Microphiopholis atra Family Amphiuridae - brittle star

Round disk (missing up above pictures); 5 narrow arms distinctly set off from disk in between lobes; arm segments with 3 spines on each side; 5 pair of plates (radial shields) on dorsal disk, each shield triangular to oval in shape, Distinguishing longer than wide, pairs joined at least at distal ends; color tan to gray, no dark Characteristics banding on arms, scales on upper surface of disk larger than on lower surface; disk may appear to be inflated or swollen; disk may be missing, as in this specimen, many times discarded when animal is disturbed (disk later regenerates). All brittle stars have a central disk with usually 5 arms distinctly set off from disk (see the banded brittle star). The easiest way to distinguish between species is Similar Species to look at the radial shields and scales on the disk. Lacking the disk, the shape of the arm scales, the number and shape of the arm spines, and several internal structures must be examined. Habitat Gulf, sandy bottoms Maximum Size 15 cm (6 in) Previous Scientific Amphiodia atra Names

Gray sea star Page 356 Luidia clathrata Family Luidiidae - starfish

Body star-shaped with 5 arms; color gray to light brown, dark gray or black Distinguishing stripe on the dorsal midline of each arm; upper surface of body covered with Characteristics small plates, lower surface of arms contain tube feet used for locomotion; lower surface of disk (center part) contains the oral cavity (mouth). Similar to the banded sea star, Luidia alternata, which has brown banding Similar Species across arm on a lighter background. The gray sea star has no banding. Habitat Gulf, usually shallow water, sandy or muddy bottoms Maximum Size 30 cm (12 in) arm span Other Common Names gray sea star, striped sea star

Rosette-scaled brittle star Page 357 Ophiolepis elegans Family Ophiuridae - brittle stars

Disk round; 5 short narrow arms distinctly set off from disk; color on aboral side (top dorsal side) brownish, sometimes with lighter spot in center of disk; arms banded; oral side (underside where mouth is) lighter, beige; aboral (upper side) of disk covered with scales in a rosette pattern, 2 large scales on each side of arms, smaller scales in center of disk, 1 column of scales between each pair of Distinguishing arms, each larger scale is completely surrounded by a row of tiny scales; on Characteristics oral side of disk, jaws (5 triangular areas making up mouth frame) surrounded on sides by small plates (called oral papillae), only one plate on tip of each jaw; 2 long slits (genital slits) between each arm; 4-6 arm spines on each side of arms; aboral arm plates (see photos) hexagonal shaped, triangular shaped accessory arm plates present on each side of arm plates, sometimes divided into 2-3 segments. These brittle stars are easy to distinguish from other brittle stars by the plate Similar Species formation (rosette pattern) on its disk. Habitat Gulf and bay, shell, sand or muddy sand bottoms Maximum Size 2.5 cm (1 in) disk width, 19 cm (7 1/2 in) arm span

Two-spined sea star Page 358 Astropecten duplicatus Family Astropectinidae - starfish

Body star-shaped with 5 arms that taper to a point; color reddish brown or gray; sides of arms with marginal plates (upper and lower), upper plates protrude slightly above middle of arms, lower plates protrude slightly beyond upper plates; the area in between the upper plates at the base of the arms is about twice the width of the upper plates; surface of plates granular; the 2 upper Distinguishing marginal plates between the arms (and sometimes surrounding plates) bear a Characteristics tubercle spine on the inner edge of the upper surface, many times the spines are worn down; lower plates and underside plates with many small spinules (very fine spines) that are somewhat flattened and blunt at the tips; the mouth plates on the underside covered with small blunt spines; small round plate (madreporite) on upper surface between arms and center of disc with squiggly folds. The marginal plates helps distinguish this family of sea stars. The spines on the Similar Species inter-arm plates (when present) distinguish this species from others of its genus. Habitat Gulf, sandy or soft sediments. Maximum Size 20 cm (8 in)

Scyllaridae - Slipper Lobsters Page 359

Slipper lobsters have body structure similar to shrimp, but they are more flattened and have a heavy thick outer skin (exoskeleton). Unlike the Maine lobsters served in restaurants, slipper lobsters have no claws. They also have no long filamentous antennae. Their antennae are modified into short, flat, broad plate-like appendages that are used to dig into soft sand or mud. This behavior leads to its nickname "the shovel-nose lobster". They are bottom dwellers and occur at great depths. Maximum sizes range from 5.5 cm (2.2 in) to 50 cm (20 in). Although they are edible, slipper lobsters don't support any major fishery. They are usually caught incidentally in other fishery operations.

Ridged slipper lobster Page 360 Scyllarides nodifer Family Scyllaridae - lobster (crustacean)

Carapace elongate, abdomen thick, dorsoventrally flattened, lobster-like; color brown with reddish orange color on antennules, legs (banded), and scattered on surface of body; antennae modified into short, well developed plates, the terminal segment is rounded and smooth, not lobed or serrated; no claws on Distinguishing any legs; 1st abdominal segment with 1 red round spot in center of back; Characteristics diffused red spots on either side of central spot; 2nd, 3rd and 4th abdominal segments with distinct raised ridges; carapace granulate, covered with small nodules; lateral margins of head form right angles ending in small tooth or spine; eyes recessed into orbits. Other slipper lobsters may have 4 red spots on 1st abdominal segment or Similar Species edges of antennae shaped into lobes or teeth, but the only the ridged slipper lobster has a ridge along the midline of the abdomen. Habitat Gulf, bottom dweller Maximum Size 35.5 cm (14 in) Other Common Names shovel-nose lobster

Page 361 Mogulidae, Styelidae - Tunicates (Sea Squirts, Salp)

Tunicates are groups of underwater sac-like filter feeders with an intake and an outflow siphon. They are a member of the phylum Chordata because they have the semblance of a vertebrate (called a notochord) and brain when they first develop. In their larval stages, they resemble tadpoles. Since the larvae cannot eat, they must find a place to attach to so that they develop into the round sac-like body of the adult. The brain and notochord are digested during this development. A common saying about sea squirts is that they "eat their own brain".

Tunicates may be solitary or colonial. Many will form mat-like colonies and can spread quickly, covering and smothering other organisms it encounters. This has caused some concern because of the altering of the marine habitat and their capability to smother shellfish beds and foul other hard substrates such as fishing gear, ship hulls and marine structures. Many are thought to be nonindigenous in areas where they occur, probably brought in on the hulls of passing ships.

Pleated sea squirt Page 362 Styela plicata Family Styelidae - tunicate

Body is ovoid with many creases or pleats, tough, leathery, warty or lumpy; color is tannish white to gray; 2 siphons extend from body, 4 lobes on tip of Distinguishing siphons, brown (or red or purple) stripes inside siphons, look like crosshairs Characteristics when siphons are closed; can squirt water through siphons when disturbed; solitary, may be singular or clustered. Similar Species The sea grape, Mogula manhattensis, is smooth and rounded, no creases. Habitat Gulf and bay, attaches to hard substrates Maximum Size 9 cm (3 1/2 in), usually 4-7 cm (1 1/2 - 2 3/4 in) Other Common Names rough sea squirt Previous Scientific Ascidia plicata Names The pleated sea squirt is considered to be an invasive species, probably from the Indo-Pacific, that was possibly brought to North America on the hull of a Comments foreign ship. The first description of the organism in the U.S. was reported in 1983, found in a fouling community on the hull of a ship. Its distribution in Texas was reported as early as the 1880's.

Sea grape Page 363 Mogula manhattensis Family Mogulidae - tunicate

Body is ovoid or globular, slightly flattened from side to side, smooth, translucent, firm, color tannish or greenish olive to yellowish green; 2 siphons protrude from one end of the body (sometimes not apparent when disturbed or Distinguishing dead), the shorter siphon has 6 lobes around the opening, the longer siphon Characteristics with 4 lobes, siphons diverging but close at the bases; can squirt water through siphons when disturbed; usually attached to hard substrates; usual grows in clusters, this is a single, solitary organism. The other common solitary sea squirt, the pleated sea squirt, Styela plicata, is Similar Species warty and creased in appearance. Habitat Gulf and bay, attaches to hard substrates Maximum Size 2.5 cm (1 in) Other Common Names sea squirt, tunicate

Page 364

Alitta succinea Cannonball jellyfish Lepas pectinata Allothyone mexicana Chiropsalmus quadrumanus Leptogorgia setacea Alternating bryozoan Chrysaora quinquechirrha Lesser mantis shrimp Amathia alternata Chthamalus fragilis lobster, Ridged slipper Amphibalanus venustus clam worm, Common Luidia clathrata Ancinus depressus Clinging jellyfish Lysiosquilla scabricauda anemone, Onion comb jelly, Sea walnut Mantis shrimp anemone, Tricolor Common clam worm mantis shrimp, Dark-banded anemone, Warty coral, Diffuse ivory bush mantis shrimp, Lesser Astrangia poculata coral, Hidden cup mantis shrimp, Offshore Astropecten duplicatus coral, Northern cup Many-ribbed jellyfish Aurelia aurita Marine leech coral, Sea whip Australian spotted jellyfish Megabalanus tintinnabulum cucumber, sea Balanus amphitrite amphitrite Mellita quinquiesperforata Dark-banded mantis shrimp Balanus eburneus Microphiopholis atra Diffuse ivory bush coral Balanus improvisus Mogula manhattensis dollar, Sand Balanus reticulatus Moon jellyfish Fragile barnacle Balanus subalbidus Mushroom jellyfish Giant purple barnacle Balanus trigonus Nemopsis bachei Gibbesia neglecta Banded brittle star Northern cup coral Goose barnacle barnacle, Bay Oculina diffusa goose barnacle, Small barnacle, Fragile Offshore mantis shrimp goose barnacle, Smooth barnacle, Giant purple Onion anemone Gray sea star Ophiolepis elegans barnacle, Goose Hemipholis elongata barnacle, Ivory pansy, Sea Hidden cup coral Paranthus rapiformis barnacle, Purple striped hydrozoan, blue button Pelagia noctiluca barnacle, Reticulated striped hydrozoan, By the wind sailor Phyllangia americana barnacle, Small goose hydrozoan, Clinging jellyfish Phyllorhiza punctata barnacle, Smooth goose hydrozoan, Many-ribbed jellyfish Physalia physalis barnacle, Striped hydrozoan, Portuguese man o' barnacle (2), Striped war Pipe cleaner sea pen barnacle, White isopod, Marine Pleated sea squirt Porpita porpita Bay barnacle isopod, Thorn Beneden’s sea cucumber Ivory barnacle Portuguese man o' war Protankyra benedeni Beroe ovata jellyfish, Australian spotted Purple striped barnacle Blue button jellyfish, Cannonball Brittle star Purple-striped jellyfish jellyfish, Clinging brittle star, Banded Renilla muelleri jellyfish, Many-ribbed brittle star, Rosette-scaled Reticulated striped barnacle jellyfish, Moon bryozoan, Alternating Rhacostoma atlanticum bryozoan, Sauerkraut jellyfish, Mushroom Rhopilema verrilli bryozoan, Spiral-tufted bushy jellyfish, Purple-striped Ridged slipper lobster Bugula nertina jellyfish, Sea nettle Bunodosoma cavernatum Rosette-scaled brittle star jellyfish, Sea wasp Sand dollar By the wind sailor leech, Marine Calliactis tricolor Lepas anatifera Sauerkraut bryozoan Calliobdella vivida Lepas anserifera Scyllarides nodifer Sea cucumber

Page 365

sea cucumber, Beneden’s Sea grape Sea nettle Sea pansy sea pen, Pipe cleaner sea squirt, Pleated sea squirt, Sea grape sea star, Gray sea star, Two-spined Sea walnut Sea wasp Sea whip slipper lobster, Ridged Small goose barnacle Smooth goose barnacle Spiral-tufted bushy bryozoan Squilla chydaea Squilla empusa starfish, Banded brittle starfish, Brittle star starfish, Gray sea star starfish, Two-spined sea star Stomolophus meleagris Striped barnacle Striped barnacle (2) Styela plicata Thorn isopod Tricolor anemone tunicate, Pleated sea squirt tunicate, Sea grape Two-spined sea star Velella velella Virgularia presbytes Warty anemone White barnacle Zoobotryon verticillatum

Page 366 Invertebrate Glossary Definition Term abdomen The body segments posterior to the carapace in crustaceans. Made of 6 segments, including the telson. In crabs, the abdomen is the flap that is flexed underneath the body. abductor muscle scar The area or depression on the inside of a bivalve shell where the foot muscle was attached. acontium (pl. acontia) Filamentous defensive organs, composed largely of stinging cells thrown out of the mouth or special pores on the body walls of certain anemones when irritated. air bladder A gas filled sac used for floatation in the Portuguese man o war and some gastropods. Also called a pneumatophore. antenna (pl. antennae) The long segmented appendages originating from behind the eyestalks in crustaceans. antennule The short segmented appendages located between and below the eyestalks in crustaceans antennule peduncle The basal portion of the antennule in crustaceans. anterior Pertaining to the head side (top or front.); opposite of posterior. aperture (1) The main opening in a gastropod shell where the foot and head extrude. (2) The opening into the body chamber between the scuta of a barnacle. apex (1) The part of gastropod shell that was formed first, typically pointed, at the posterior end of the shell. (2) The upper angle of the opercular plates in barnacles. apophysis A hard spoon-shaped protuberance extending from underneath the beak of a bivalve. apron The abdomen which forms a flap that is flexed underneath the body of the crab.

Aristotle's lantern The chewing organism of sea urchins and sand dollars, made up of five teeth (forming a jaw) and a fleshy tongue-like structure. arm Shorter, thicker (as opposed to tentacles), fleshy extension hanging beneath the head of a cephalopod. Usually has suckers most of its length. axial Running longitudinally across the whorls in gastropods. basal disk The base of a sea anemone that attaches to the substrate. basal margin The lower margin of a plate in barnacles. basal plate The bottom plate and place of attachment for barnacles. May be calcareous or membranous. beak (1) In bivalves, the pointed or rounded end of the shell in the hinge area. Also called apex or umbo. (2) In cephalopods, the pair of curved sharp teeth at the opening of the mouth. (3) The lower curved angle of the scutum in goose barnacles or the apex of the tergum with a curved beak-like point in other barnacles. bell The gelatinous, radially symmetrical covering of a jellyfish. The mouth is on the underside of the bell. bicuspid Having two points. bifurcate Ending with two branches or tips. bivalve A mollusk that is surrounded by 2 hinged shells. Includes clams, oysters, and mussels. body whorl The lowest and largest whorl of a gastropod shell Page 367 Invertebrate Glossary branchial lamellae Folds of the gills in nudibranchs. byssal threads (byssus) A bundle of threads used by bivalves to attach to hard surfaces. calcareous plates A ring of plates surrounding the esophagus in a sea cucumber. callus A raised hardened part on a shell. calyx (pl. calyces) The depression or extension in a coral skeleton that houses the polyp. cancellate Lattice-like; e.g., radial ribs crossed by concentric ribs. capitulum The portion of the barnacle (shelled part) above the peduncle of a goose barnacle. carapace The hard dorsal covering of the head and thorax of the body. Does not cover the abdomen. carapace length In crustaceans, the distance from the anterior most part of the head (usually the rostrum) to the posterior most part of the carapace (dose not include the abdomen). carapace width In crabs, the distance between the lateral spines (the posterior most spines) of the carapace. This measurement is usually used to describe crab size. cardinal teeth Teeth on the hinge line in bivalves. carina (1) A raised ridge. (2) In goose barnacles, an unpaired narrow plate adjacent to the paired scutum and tergum plates. One of the parietes in other barnacles. carpus The 3rd segment from the distal end of a crustacean leg. In a clawed leg, it is the segment where the appendage flexes (i.e. the elbow). cephalopod A marine mollusk having bilateral symmetry, a well developed head and eyes, having arms and tentacles. Includes octopuses, squids, cuttlefishes and the nautilus. cephalothorax The fused head and thorax of many crustaceans. ceras (pl cerata) Dorsal and lateral outgrowths on the upper surfaces of the body of nudibranchs. chela (pl. chelae) The last two segments of a leg that forms a pincer or claw. It includes the movable and immovable fingers and the palm, except in mantis shrimps (no movable finger). chelate Possesses a chela (claw). chelipeds The 1st pair of legs (anterior most) when they have claws in crustaceans. chitin A tough, semitransparent substance (a nitrogen-containing polysaccharide) that forms a protective covering. chitinous Made of a tough, semitransparent substance (a nitrogen-containing polysaccharide) that forms a protective covering. chondrophore A hard scooped-out projection or pocket on the hinge line of a bivalve. chromatophore A cell containing pigment. cilia Minute hair-like structures that can move rhythmically and are used for locomotion or moving fluids and particles along a structure. cirrus (pl. cirri) Biramous appendages in barnacles used to filter the water for food. claw appendage The entire appendage that possesses a claw, from the fingers to the point of attachment to the body. coenenchyme The common tissue that connects colonial polyps. coenosteum Skeletal material between the walls of the corallites of a coral. columella (1) The central part of the calyx of a coral skeleton where the lower elements of the septa fuse. (2) The central pillar of a gastropod shell around which the whorls form. It is partially or totally hidden inside the shell. concave Curving inward. concentric Ridges or lines that run parallel to the margin of a shell in bivalves. Page 368 Invertebrate Glossary convex Curving outward. corallite The part of a coral skeleton produced by a single polyp. corallum (pl. coralla) The entire coral skeleton. costa (pl. costae) (1) Extension of the septum to the outside wall of the corallite of a coral. (2) Tubular or circular ridge on the surface of a shell in mollusks. crenate Having a round-tooth or scalloped edge. crenulate Having margins that are scalloped, indented, wrinkled or notched. crest An elevated, irregularly toothed ridge on a claw crustacean An invertebrate with a segmented body, a hard external shell (exoskeleton), paired and segmented appendages and having 2 pairs of antennae. Includes shrimp, crabs, lobsters, barnacles and mantis shrimps. dactylus (dactyl) The segment of a crustacean leg that is most distal (farthest) from the body. In a clawed leg, it is the movable finger segment. deck A thin plate of shell underneath the beak that connects the anterior and posterior margins of a shell. dentate With angular or tooth-like projections of a margin. dextral Right-handed. In gastropods, when the whorls wind clockwise. distal Farthest from the center of the body. dorsal Pertaining to the back side (top or rear); opposite of ventral. dorsolateral Upper part of sides. endopod The inner pair of flattened appendages of the tail fan or at the end of a biramous segment in crustaceans. escutcheon A depression on the posterior dorsal margin of bivalve shells. exopod The outer pair of flattened appendages of the tail fan or at the end of a biramous segment in crustaceans. eyescales Scale-like structure at the base of the eye stalk in crustaceans. fingers The parts of the claw that opposes each other, one being movable, the other stationary. foot The muscular part of a mollusk's body used for locomotion. gastropod A mollusk typically having a single, coiled shell (cap-shaped in limpets, absent in nudibranchs), a flattened muscular foot used for locomotion, and eyes and tentacles on a distinct head. Includes snails, whelks, limpets and slugs. gladius The internal pen (hard structure) of a squid. hepatic spine Spine on the anterior lateral side of the carapace, behind and slightly below the eye orbit in crustaceans. hinge The toothed area beneath the beak and ligament that helps hold the two shells together in bivalves. hinge teeth Small nodules or projections on the hinge line of a bivalve shell. Helps hold the shells together. Also called cardinal teeth. hyponotal lamellae Folds on the underside of a nudibranch that contain the branches of the digestive gland. immovable finger The finger of the claw that does not move. inflated Not flat. The degree of plumpness of the bivalve shell. interorbital The edge of the carapace between the orbits (eye sockets) in crustaceans. keel A ridge. lamella (pl. lamellae) A thin plate or fold of hard or soft tissue. lateral The sides of a body. Page 369 Invertebrate Glossary lateral fins Fleshy fin-like projections on the either side of the mantle in squids. lateral spine The spines on the outside edges of the carapace at its widest point (usually the posterior most spines on the sides) in crabs. lateral teeth Small nodules or projections on the inside lateral edges in bivalve shells. Keeps the shells from sliding anteriorly and posteriorly. left valve In bivalves with a pallial sinus, when looking at the underside of a shell, the pallial sinus will be on the left in the left valve. In shells with only 1 muscle scar (posterior), the scar favors the left side in a left valve. Also look at the ligature and lunule (if present). The ligature is on the posterior side and lunule is on the anterior side of a valve. In oysters, the left valve is the attached shell. ligament An elastic band of connective tissue that connects and holds the shells together in bivalves. ligature area Area above the hinge, usually between or posterior to the beaks, where the ligament occurs in bivalves. lunule (1) A depression on the anterior dorsal margin of bivalve shells. (2) Oval holes in the body of some sand dollars. The purpose of lunules is not known for sure. It may help the sand dollar to burrow, right itself, find food or to prevent the waves from lifting it out of the sand major cheliped The largest clawed appendage when the claws are unequal in size. mantle (1) The membranous covering in a bivalve shell that lies next to the shell. (2) The external soft body of a squid. Does not include internal organs, arms or tentacles. manus In a clawed leg, the manus makes up the immovable finger and palm. Also called the propodus. maxillipeds The three outer pairs of mouth appendages in crustaceans. merus The 4th segment from the end of a leg appendage in crustaceans. mesoplax An additional plate behind the beaks in some bivalves. metaplax An additional plate above the beaks in some bivalves. mollusk An invertebrate with a soft, unsegmented body, usually having a hard outer shell or a reduced internal shell. Includes snails (gastropods), clams (bivalves), squids and octopi (cephalopods) and tusk shells (scaphopods). mottling Areas of color with no particular shape or pattern. movable finger The finger of the claw that is movable. muscle scar The area or depression on the inside of a bivalve shell where the foot muscle was attached. nacreous layer Shiny, iridescent part of shell. nodules A small lump or knot. nudibranch A marine shell-less gastropod with external gills and appendages, sometimes with brightly colored bodies. Often called a sea slug. oblique Angled, either upward or downward, usually refers to mouths, stripes or lines. opercular plates The movable plates in the orifice of the shell in barnacles. Consists of the paired scuta and paired terga. operculum The external hard plate or door at the aperture opening in gastropod shells.. oral arms Soft, sometimes convoluted, structures that hang beneath the bell of a jellyfish that are used to pass food to the mouth. oral cavity Mouth. oral disk The membranous disk that contains the mouth in sea anemones. orbit The eye socket. Page 370 Invertebrate Glossary orbital teeth Projections or spines flanking each side of the eye socket. orifice The dorsal opening of the shell in barnacles. ossicle A microscopic, calcified skeletal element found in the body walls, tentacles and tube feet of a sea cucumber. pallial line A line on the inside of a bivalve shell that indicates the edge of where the mantle lay. pallial sinus An indentation in the pallial line of bivalve shells. palm The part of the claw behind the movable and immovable fingers. paries (pl. parietes) A triangular plate on a barnacle. pedalium (pl. pedalia) Gelatinous, muscular extension of the bell of some jellyfish. peduncle A fleshy stalk used to attach to a hard surface. pen A semi-hard, feather-shaped structure, inside a squid's mantle, used for support and muscle attachment. Also called the gladius. pereopods In shrimp, the 1st 5 pair of long walking legs, attached to the cephalothorax, the 1st few of which may or may not be chelate. periostracum A protective skin that covers the outside of mollusk shells. petalloids Specialize tube feet, used as gills, arranged in a 5-petalled flower shape, on the upper surface of a sand dollar. petasma Genital structures attached to the 1st pair of swimming legs in male penaeid shrimp. Looks like a pair of extensions, one from each leg with ends united together in larger shrimp. pleopods In shrimp, the paired swimming legs that are attached to the abdomen, usually biramous. polyp An individual organism, usually cylindrical in shape with an oral end surrounded by tentacles and a base for attachment. When in colonies, each polyp usually serves only one function, such as digestion or reproduction. posterior Pertaining to the tail side (bottom or rear); opposite of anterior. propodus The second segment from the distal end of a leg. In a clawed leg, the propodus is the segment with the immovable finger and palm. protoplax An additional plate in front of the beaks in some bivalves. proximal Nearest the center of the body or point of attachment to body. rachis The stem or main shaft of a structure. radial Extending out from a common point radial shield One of two plates at the base of each arm on the disk of a brittlestar. radius (pl. radii) The walls in between the triangular plates in barnacles. rhinophores A pair of tentacles, on the head of nudibranchs, which contain scent or taste receptors. right valve In bivalves with a pallial sinus, when looking at the underside of a shell, the pallial sinus will be on the right in the right valve. In shells with only 1 muscle scar (posterior), the scar favors the right side of a right valve. Also look at the ligature and lunule (if present). The ligature is on the posterior side and lunule is on the anterior side of a valve. In oysters, the right valve is the unattached shell. rostrum An extension of the carapace between the eyes projecting anteriorly. sail A stiff, upright structure on some hydroids that is used to catch the wind to enable movement. scaly With closely set or overlapping flat, scale-like projections. sclerite A skeletal element in soft corals, composed of calcium spicules. Page 371 Invertebrate Glossary scutum (pl. scuta) One of a pair of internal opercular plates in barnacles (in goose barnacles, the lower external triangular plate). septum (pl. septa) (1) Skeletal radiating plates inside the calyx of a coral. (2) A hardened partition which subdivides a cavity in a mollusk shell. serrated Saw-toothed. seta (pl. setae) A small hair. sinistral Left-handed. In gastropods, when the whorls wind counterclockwise. siphon A tubular structure for bringing in or expelling fluids. siphonal canal A channeled extension in a gastropod shell from which the siphon extends. siphonal notch A notch at the base of the siphonal canal in gastropods. spicule Minute hard pointed projections. spine A sharp pointed projection. spire The coiling whorls above the aperture of a gastropod. stolon In bryozoans, branch-like extensions (not considered "true" branches as in plants). stomatopod A marine crustacean with strongly toothed, scissor-like claws and with gills on their abdomen. Also called mantis shrimp. stromboid notch A notch or indentation in the lower outer lip of conch gastropods, used to extend 1 of its stalked eyes out of the shell. suture Junction between whorls in gastropods. tail The abdomen in shrimp. tail fan Two pairs of flattened appendages that attach to the last segment of the abdomen in crustaceans. Also called uropods. teeth Projections or spines. telson The most terminal segment of the abdomen in crustaceans. Forms the center part of the tail fan. tentacle (1) In cephalopods, an elongated arm use to capture prey (usually with suckers on the distal ends). (2) One of several narrow elongated string-like processes projecting from the lower surface of the bell of a jellyfish. Tentacles contain the stinging cells. (3) One of many motile and retractable arms surrounding the oral cavity of an anemone. Tentacles contain the stinging cells. (4) Fleshy extensions on the head of a gastropod. tergum (pl. terga) One of a pair of internal opercular plates in barnacles (in goose barnacles, the upper external plate). tergum spur A projection on the basal margin of the tergum in barnacles. terminal process In bryozoans, extra extension at the end of each stolon (branch); may be single or branched. theca The wall of a corallite of a coral. thelycum External pocket on the underside of the thorax of female penaeid shrimp, used for receiving the male sperm sac. Usually covered by 2 lateral plates (absent in white shrimp). third maxillipeds The outermost part of the mouth appendages in crustaceans. thoracic segment A segment between the carapace and the abdomen in mantis shrimp. The last pairs of walking legs are attached underneath. thorax The part of the body between the head and abdomen. tube feet Small tube-like projections on the underside of a starfish's arm that are used for locomotion, feeding and respiration. tubercle A calcified and hard protuberance. Page 372 Invertebrate Glossary umbilicus A sunken or depressed area at the base of a gastropod. umbo (pl. umbones) The beak in a bivalve shell. uropod Two pairs of flattened appendages that attach to the last segment of the abdomen of crustaceans. The tail fan. valve A shell of a bivalve. vane The broad, lateral part on both sides of the rachis (central shaft) of a squid's pen (internal hard structure). varix (pl. varices) Longitudinal thickened ridge found in some gastropods. ventral Pertaining to the front or bottom side; opposite of dorsal. walking legs Legs that are used for walking that do not possess a claw (except in shrimp, may be chelate.) whorl A spiral of a gastropod shell. zooid An individual polyp in a colony, as in bryozoans