Phylum: Annelida Nephtys caecoides Class: Polychaeta Order: Phyllodocida A sand worm Family: Nephtyidae Description setigers from worm posterior, there is a Size: Individuals up to 100 mm in length and recurved cirrus between the parapodial lobes 5–8 mm in width, with up to 129 segments (Fig. 5) (Lovell 1997). In juvenile specimens, (Hartman 1968; Hilbig 1997). The illustrated this can be nearly straight (Fauchald 1977). specimen has 115 segments (Fig. 1). The interramal cirrus is larger than the dorsal Color: A strong pigment pattern on cirrus, except in the last nine segments prostomium and first few segments (Fig. 2) (Hartman 1968). persists through preservation. Body usually Setae (chaetae): All nephtyid setae are steel to dark grey (Hartman 1938). simple and the setae of both rami are of General Morphology: Anterior cylindrical in similar morphology. Overall, there are four cross-section and becomes slender and main types of nephtyid setae including rectangular posteriorly (Nephtyidae, Blake capillary (e.g. spinose), barred (which are pre- and Ruff 2007). acicular), lyrate and setae with spines Body: Trim, stiff and slender in appearance (Dnestrovskaya and Jirkov 2011). Nephtys (Hartman 1938), rectangular in cross section caecoides exhibits three setal types; 1) a (Hartman and Reish 1950). Anterior third is bunch of short, stiff and slender barred setae stout and wide, while the middle and posterior (pre-acicular) (Fig. 4a, b); 2) post-acicular regions become slender and more flexible setae with upper fascicle of spinulose (Hilbig 1997). First segment is incomplete capillaries and large middle fascicle with wide dorsally (Hartman 1968) (Fig. 2). spinose setae (Fig. 4c); 3) neurosetae with Anterior: Prostomium is trapezoidal upper smooth capillaries and spinose setae in or rounded and changes shape when middle fascicle and spinulose capillaries in proboscis is everted (Fig. 2) (Hilbig lower fascicle. Setae of first parapodium are 1997). pointed anteriorly and the remainder are Trunk: Thick with widely separated lateral (Fig. 2) (Hilbig 1997). A single acicula parapodial rami (Fig. 1, 5). is present in each ramus, and is transparent Posterior: Pygidium bears long or yellow and tapers to a fine tip (Hilbig 1997). caudal cirrus that is sometimes lost Eyes/Eyespots: Absent in adults (Hilbig during collection or preservation. 1997). Parapodia: Parapodia are biramous and Anterior Appendages: Prostomium bears rami are widely separated, densely packed four small simple antennae, in two pairs which and their setae are fan-shaped (Nephtyidae, are widely separated. One pair of nuchal Blake and Ruff 2007). Both noto- and organs present (Hilbig 1997). neuropodia are rounded in the worm posterior Branchiae: The interramal cirri, which are (Fig. 5b) and the acicular lobes are incised in inserted just beneath each dorsal cirrus, are the middle of the worm (Fig. 5a). First sometimes called branchiae (Blake and Ruff parapodial pair pointed anterior (Hilbig 1997). 2007). Another defining characteristic of the Burrow/Tube: Nephtyidae are the interramal cirri that are Pharynx: Bears short and wide proboscis inserted just beneath dorsal cirri, which are with a variety of papillae, their number and small, in anterior setigers (Blake and Ruff arrangement is of taxonomic significance 2007) (Fig. 5). Beginning with the fourth (Blake and Ruff 2007). The proboscis in setiger, and continuing to within 10–20 Nephtys species can be divided into three Hiebert, T.C. 2015. Nephytes caecoides. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR. A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: http://hdl.handle.net/1794/12673 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] distinct regions including the proximal, sub- red spot at center) of pigmentation on the distal and distal (Lovell 1997) (Fig. 3). In N. lower end of the prostomium, a smooth caecoides there are 20 pairs of distal papillae, proboscis without medial papilla, soft silky an unpaired mid-dorsal papilla and 22 rows of flowing setae and interramal cirri beginning sub-terminal papillae with 3–6 papillae per on the third setiger. row (five per row in the illustrated specimen). Three other Nephtys species that Mid-dorsal and mid-ventral distal areas of the are not so easily confused with N. proboscis are without papillae and smooth caecoides. N. cornuta, a small species (Lovell 1997; Hilbig 1997) (Fig. 3). (less than 15 mm in length) that can be Genitalia: identified by its distinctive bifid ventral and Nephridia: posterior antennae. This species often retains larval eyes on the third setiger, a Possible Misidentifications feature which is usually lost in other closely Worms of the family Nephtyidae can be related species (Blake and Ruff 2007). N. distinguished by their anteriorly cylindrical cornuta can also be differentiated because it and posteriorly rectangular bodies (in cross has 18 distal paired papillae (instead of 20 section), well-developed bi-lobed parapodia, in N. caecoides) and interramal cirri that interramal cirri, four small prostomial begin on setiger five (rather than four in N. antennae, and eversible globular proboscis caecoides) (Lovell 1997). N. punctata is with terminal rows of papillae. They are much like N. caeca in size and form strong and muscular worms that can be (Hartman 1938), but has interramal cirri good burrowers and strong swimmers beginning on setiger 8–10, and with incised (Blake and Ruff 2007). Nephtyids acicular lobes in the anterior parapodia. superficially resemble the genus Nereis, This species is large and muscular with however, they have no long anterior wide body and short parapodia and is appendages (tentacular cirri) and their currently only reported in southern proboscis armature is quite different (Kozloff California (Hilbig 1997; Blake and Ruff 1993). The distinctive taxonomic characters 2007) of N. caecoides include 20 distal paired N. parva, colorless except for a dark papillae, 22 rows of sub-distal papillae with spot in the middle of its prostomium 3–6 papillae per row, an unpaired mid- (Hartman 1968), a smooth proboscis dorsal papilla and interramal cirri beginning proximally, no medial papilla, eyespots on on setiger four (Lovell 1997). its third setiger and interramal cirri Some Nephtys species are beginning on the fourth setiger. The type distinguished from each other by very fine material from this species is suspected to morphological details. The species most have been miscurated and the holotype closely related to and difficult to differentiate appears to be that of N. cornuta, while the from N. caecoides include N. caeca and N. species description and paratypes match N. californiensis. N. caeca is slightly larger, caecoides more closely. Thus, this species iridescent, with no prostomial pigmentation is not a currently a valid taxon (Lovell 1997; and a rough proboscis with no unpaired Blake and Ruff 2007). medial papilla. Furthermore, this species N. ferruginea has the same number has interramal cirri beginning on the fifth or of paired distal and sub-distal papillae, sixth setiger, not the fourth (as in N. however, the interramal cirri in this species caecoides). This is a northern species, begin on setiger three, rather than four in N. which is locally rare, and likely introduced caecoides (Lovell 1997). N. ferruginea from the eastern United States (Blake and individuals have a distinct rust colored Ruff 2007). N. californiensis is found mostly pigment in a V-shape pattern on on the outer coast, or if in bays, only in very prostomium in addition to transverse bars clean coarse sand. It has a distinctive V- mid dorsally on the first 20 setigers and shaped pigment pattern (sometimes with oblique stripes dorsolaterally (Hilbig 1997). Hiebert, T.C. 2015. Nephytes caecoides. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR. Ecological Information developed prototrochs and telotrochs, with Range: Type locality is Tomales Bay, neurotrochs present in young larvae. California (Hartman 1968). Known range Nephtyid larvae are common in plankton includes western Canada to southern samples and are recognized by their shape California. and species-specific bright body colors Local Distribution: Coos Bay distribution (Lacalli 1980; Fernald et al. 1987). A locally includes many stations, especially those collected larva identified to the genus Nephtys within the South Slough. The distribution of with DNA sequence data had distinct red N. caecoides is very close to Scoletoma pigment bands near the prototroch and zonata but occurs in sandier mud (Porch telotroch and blue pigment within the gut 1970). (http://invert- Habitat: Mud, sand and mixed sediments of embryo.blogspot.com/2012/12/confirmed- bays and lagoons. N. caecoides also occurs identity-of-wild-caught.html). Nephtyid in eelgrass flats (Hartman 1938) but is not trochophore and metatrochophore larvae are found in areas with large amounts of silt predatory (Fernald et al. 1987; Crumrine (Clark and Haderlie 1962). Instead this 2001). species prefers fine, stable substrate. Juvenile: The prostomium becomes angular Salinity: Can tolerate low salinities, (i.e. rather than rounded in newly metamorphosed freshwater stream beds) (Porch 1970). individuals (Fig. 5, Lacalli 1980). Juveniles Temperature: may possess eyes on one of the first three Tidal Level: Intertidal to littoral depths (one setigers that are usually, although not always specimen from 46–106 meters) (Hartman and (e.g. N. cornuta), lost in adults (Hilbig 1997). Reish 1950). Densest populations at Bodega Longevity: Bay at + 0.32 meters and at -0.52 meters Growth Rate: MLLW (Clark and Haderlie 1962). Individuals Food: Nephtys caecoides is carnivorous observed from 0.0 m to +1.2 m, with 15 (Clark and Haderlie 1962).