Eudistylia Vancouveri Phylum: Annelida Class: Polychaeta Order: Canalipalpata, Sabellida a Feather-Duster Worm Family: Sabellidae, Sabellinae
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Phylum: Annelida Eudistylia vancouveri Class: Polychaeta Order: Canalipalpata, Sabellida A feather-duster worm Family: Sabellidae, Sabellinae Taxonomy: Eudistylia polymorpha was Anterior: Prostomium or head is originally described as Sabella vancouveri reduced and indistinguishable (Figs. 4, and later re-described and figured by Johnson 5). (1901) as Bispira polymorpha, when Trunk: Thorax of eight segments and Eudistylia was differentiated by characters of abdomen of many segments. thoracic notosetae which were later deemed Thoracic collar with four lobes (Fig. 4) insignificant at the genus level and the two that are visible on the ventral side with genera were synonymized to Eudistylia no long thoracic membrane. Collar is (Fauvel 1927 and Johansson 1927 in Banse used to build the tube by incorporating 1979). Since then, several species have sand grains with exuded mucus and been synonymized with E. polymorpha attaching a “rope” to the tube anterior. including Sabella vancouveri and S. Posterior: Worm body tapers toward columbiana, E. abbreviata, E. gigantea, E. posterior to slender yet broad plumosa and E. tenella (Banse 1979). pygidium (Fig. 1). Parapodia: Biramous, (Figs. 1, 6) except for Description first or collar segment, which has only Size: One of the largest sabellids. notopodia (Hartman 1969). In thoracic Individuals range in size from 300–480 mm in setigers (setigers 2–8), the notopodia have length and 15–20 mm in width, where the bundles of long and slender setae (Figs. 7b, tube is up to 10 mm diameter (Hartman 1969; c). The neuropodia on setigers 2–8 have Kozloff 1974). This description is based on pairs of short uncini (hooks) (Fig. 7a) encased illustrated and dissected specimens (Fig. 1). in zipper-like, raised ridges called tori (Fig. 6). Color: Crown of tentacles dark red and This arrangement is reversed in the green and radially striped (5–8 stripes) abdomen, where the notopodia contain hooks (Hartman 1969; Kozloff 1974). Hartman in the abdominal segments and the (1969) reports tentacles that were dark red neuropodia have long spines (Fig. 6). and orange or yellow in California, but this Setae (chaetae): Thoracic notosetae of two description may refer to E. polymorpha, in kinds (genus Eudistylia): one long, slender part (see possible misidentifications). and bilimbate (Fig. 7b) and the other Some tentacles are white-tipped. The spatulate and not scimitar-like (Fig. 7c). illustrated specimen (Fig. 1) had a buff Abdominal notosetae are short avicular uncini colored body with light green markings and (Fig. 7e). Thoracic neurosetae in torus, white spots. The tube is buff or grey in color. pennoned or flagged and acivular hooks or General Morphology: A robust worm with a uncini arranged in a long row of about 20 short tentacular crown that is brilliantly pairs (Fig. 7a). Abdominal neurosetae long colored (Hartman 1969). Worms can be and pointed (Fig. 7d). recognized in large groups called hummocks Eyes/Eyespots: Anterior eyespots lacking where tubes are built upon each other and however, eyespots are present on radiole ribs resemble shrubs (e.g. Fig. 3). where each radiole has 5–7 black eyes in a Body: Body divided into thoracic and row (Hartman 1969) (Fig. 2) on the dorsal- abdominal regions where abdomen gradually most radiole pair (Blake and Ruff 2007). tapers posteriorly. Anterior Appendages: Anterior crown of tentacles made up of two equal parts Hiebert, T.C. 2014. Eudistylia vancouveri. 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/1794/12660 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to [email protected] composed of many radioles (Fig. 1). individual branches of the crown and are Radioles, also called cirri or tentacles, are single and undivided with forked, simple side branches or pinnules (Fig. 2) and dark clearly defined into thorax, abdomen and eyespots along the lower edge, especially long caudal region. near radiole bases (Fig. 2). Bases are Within the family Sabellidae, there spiraled twice (genus Eudistylia). Crown are two subfamilies represented locally, conceals mouth and head and edges are Fabriciinae and Sabellinae. The subfamily smooth and not incised (Hartman 1969) (Fig. Fabriciinae differs from the Sabellinae in its 5). small size and in its temporary fragile mucus Branchiae: Blood within branchiae is green tubes. Several northwest genera exist, in color due to the respiratory pigment including: chlorocruorin (Abbott and Reish 1980; Chone species are tiny worms with a Terwilliger et al. 1975). Branchial base membrane partly uniting its radioles and a without groove dorsally (Blake and Ruff thoracic collar which is complete and not 2007). lobed. Local species have 15 or fewer pairs Burrow/Tube: Tube is long, cylindrical, of radioles. flexible, permanent, tough, leathery and Fabricia species have few segments membranous. It is made of mucus and and sparse radioles and individuals are quite cemented sediment and is not calcareous and small. Amphicorina has 7–8 abdominal without operculum. Worm can completely segments, not three. withdraw into tube. The subfamily Sabellinae (to which E. Pharynx: vancouveri belongs) is noted for its avicular Genitalia: uncini in the thoracic neuropodia, and for its Nephridia: permanent, tough and leathery tubes. Other genera of the sub-family include: Possible Misidentifications Schizobranchia (=split branch) Characteristics of the family Sabellidae are species are common from central California the tentacular crown of bipinnate radioles, to Puget Sound (Blake and Ruff 2007). This lack of gills on the body segments and setal small worm occurs in great masses on floats. types reversed from thoracic to abdominal Its radioles are branched, not single and it is regions (see parapodia). These characters often tan colored with a bright red crown (not they share with the Serpulidae, however, striped) (Kozloff 1974). Schizobranchia sabellids are distinct from serpulids by insignis (Bush, 1905) often occurs with and having a leathery tube of mucus and sand is intermixed in clumps with Eudistylia which lacks an operculum or trap door. vancouveri (Blake and Ruff 2007). Serpulids, on the other hand, have a Megalomma species usually occurs calcareous tube and a staked operculum in deep water and are rare intertidally. The resembling a golf tee (O’Donoghue 1924). composite eyes which characterize this Other tube worms include the genus are spiraled around the radiole ends Terebellidae, which have soft cirri that (Blake 1975). cannot be completely retracted into the tube Pseudopotamilla includes three local (as sabellids can). Terebellids sometimes species of small, rare tube worms which have gills on their anterior segments (see share with Eudistylia the simple pinnate Thelepus crispus and Pista pacifica), and crown of radioles, but the bases of whose their setal types are not inverted (Blake two crowns of tentacles are curved into 1975). semicircles and are not spiraled. A family with an easily confusing name is Sabella species bear two lobes on the Sabellaridae, which builds sand tubes. the thoracic collar, rather than four in These have 2–3 rows of paleae (flattened Eudistylia vancouveri. All members of this setae) forming highly modified cephalic genus have spiraled fascicles on their structures, but not crowns. Their bodies are Hiebert, T.C. 2014. Eudistylia vancouveri. 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. abdominal setae (Knight-Jones and Perkins Tidal Level: Collected on floats just below 1998). water surface, intertidal (Hartman 1969). Brispira species are found in Associates: Associates include the membranous tubes on rocky bottoms. This copepod, Gastrodelphys dalesi (at Tomales genus was revised in 1998 (Knight-Jones Point, California), but worm tubes form a and Perkins) and now includes Brispira complex microhabitat in which many animals (=Sabella) crassicornis which has paired and plants survive. Tube hummocks of eyespots in deep red bands on its radioles Eudistylia vancouveri are often interspersed (Blake 1975). with another sabellid, Schizobranchia insignis Myxicola species have a thick, (Blake and Ruff 2007). transparent mucus sheath or gelatinous tube Abundance: Gregarious and can be the covering its body and its radioles are joined principal sabellid in rocky habitats (e.g. Puget by a web for most of their length (Fitzhugh Sound, Kozloff 1974). Individuals grow in 1989). large clumps, in shrub-like masses called Eudistylia vancouveri and E. hummocks (Ricketts and Calvin 1971) (Fig. polymorpha, may in fact be the same 3). species (Ricketts and Calvin 1971) and some believe that hybridization occurs Life-History Information (Blake and Ruff 2007). There are two Reproduction: Developmental modes obvious differences between them: E. among sabellids are highly variable from polymorpha does not have striped radioles, brooded lecithotrophy, to direct development, they are a solid dark red with orange tips and planktonic larvae that are either and the dorsal edge of the crown of radioles planktotrophic or lecithotrophic (Crumrine in not