Phylum: Annelida Thelepus crispus Class: Polychaeta, Sedentaria, Canalipalpata Order: Terebellida, Terebellomorpha A terebellid worm Family: Terebellidae, Theleponinae Description (Hartman 1969). Notosetae present from Size: Individuals range in size from 70–280 second branchial segment (third body mm in length (Hartman 1969). The greatest segment) and continue almost to the worm body width at segments 10–16 is 13 mm (88 posterior (to 14th segment from end in mature –147 segments). The dissected individual specimens) (Hutchings and Glasby 1986). All on which this description is based was 120 neurosetae short handled, avicular (bird-like) mm in length (from Coos Bay, Fig. 1). uncini, imbedded in a single row on oval- Color: Pinkish orange and cream with bright shaped tori (Figs. 3, 5) where the single row red branchiae, dark pink prostomium and curves into a hook, then a ring in latter gray tentacles and peristomium. segments (Fig. 3). Each uncinus bears a General Morphology: Worm rather stout thick, short fang surmounted by 4–5 small and cigar-shaped. teeth (Hartman 1969) (two in this specimen) Body: Two distinct body regions consisting (Fig. 4). Uncini begin on the fifth body of a broad thorax with neuro- and notopodia segment (third setiger), however, Johnson and a tapering abdomen with only neuropo- (1901) and Hartman (1969) have uncini dia. beginning on setiger two. Anterior: Prostomium reduced, with Eyes/Eyespots: None. ample dorsal flap transversely corrugated Anterior Appendages: Feeding tentacles are dorsally (Fig. 5). Peristomium with circlet of long (Fig. 1), filamentous, white and mucus strongly grooved, unbranched tentacles (Fig. covered. 5), which cannot be retracted fully (as in Am- Branchiae: Branchiae present (subfamily pharctidae). Thelepinae) and with many slender single fila- Trunk: Thorax with well over 25 seg- ments (Fig. 1). Three filiform pairs are pre- ments (Hartman and Reish 1950). Anterior sent on segments two, three, and four thorax not greatly enlarged. Thoracic ven- (Hartman 1969; Hutchings and Glasby 1986). tral plates not clearly distinguishable (as in Branchiae contain vascular hemoglobin (as in Pista) and do not extend into lappets. Pista pacifica), which transfers oxygen to coe- Posterior: lomic hemoglobin (Garlick and Terwilliger Parapodia: Thoracic segments biramous 1974). and abdominal segments bear only neu- Burrow/Tube: Stiff tube of coarse sand, grav- ropodia. Parapodial tori (a ridge-like para- el and shells over a chitinous base is attached podial branch) are longest on setigers 9–21 to shell and/or rock or within empty burrows. and become papillar posteriorly (Hartman Pharynx: 1969). Genitalia: Setae (chaetae): Notosetae appear as Nephridia: groups of long capillary setae in raised para- Possible Misidentifications podia (Figs. 1, 5). Each seta is limbate The Terebellidae are one of a num- (wing-shaped) with smooth margins (Fig. 2) ber of tube-building polychaete families with A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: https://oimb.uoregon.edu/oregon-estuarine-invertebrates and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] Hiebert, T.C. 2015. Thelepus crispus. 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. soft tentacles for deposit feeding and with Streblosoma spp. can be further gills on their anterior segments (Blake differentiated from T. crispus in that 1975). Many terebellids occur in our members of the former genus have many Northwest bays. All of them have bodies eyespots, a tightly coiled tube, a small with numerous segments and two distinct number of tentacles and conspicuous regions, a tapering abdomen with neuro- ventral plates. Streblosoma crassibranchia setae only and both capillary setae and is reported in southern and central California uncinigerous tori on the thorax (Berkeley (Blake and Ruff 2007). Streblosoma bairdi, and Berkeley 1952). They all have a modi- reported from Puget Sound, is small (to 80 fied and reduced head with the prostomi- mm), with only 30-40 setigers, a fragile um and peristomium at least partly fused, posterior, notosetae beginning on the first and many non-retractible filiform tentacles branchial segment, and uncinal tori, which emerging from the folded prostomium. become projecting rectangular pinnules Terebellids are relatively large, usually (Berkeley and Berkeley 1952; Kozloff 1974). over 5 cm in length, and havefeeding ten- There are three other species of The- tacles (“spaghetti worms”) which are not lepus, which might occur in our area. The completely retractile into the worm's reported range of Thelepus hamatus is from mouth. Their branchiae are not simple, but Alaska to California (Hilbig 2000) with a consist of masses of aborescent or distribution that is probably subtidal and filamentous structures. There are 14 local below. This species is a small, delicate terrebellid genera (Blake and Ruff 2007): terebellid, which is about 26 mm in length, Amaeana, Eupolymnia, Lanice, Loimia, with only a few thick, deeply grooved Nicolea, Neoamphitrite, Neoleprea, tentacles. It has only two pairs of Polycirrus, Proclea, Ramex, Spinosphaera, branchiae, with few filaments and is orange. Streblosoma, Thelepus and Pista. Thelepus setosus (= Phenacia setosa), a The subfamily Thelepinae, which in- cosmopolitan terebellid, is distinguished cludes the genus Thelepus, always have from T. crispus chiefly because all of its branchiae and uncini, which occur in single uncini are in single rows which do not curve rows which may curve around into a circle into rings as in T. crispus and the uncini are (e.g. Fig. 3). Other genera in this subfami- on projecting rectangular pinnules as in T. ly include Streblosoma and Naneva hamatus (Berkeley and Berkeley 1952). (Hartman 1969). The latter does not occur Thelepus setosus has three pairs of in our area. The main difference between branchiae and capillaries beginning on the Streblosoma and Thelepus is the position third segment as in T. crispus. Thelepus of the first notopodium and neuropodium setosus also has conspicuous black which is the second and third segments eyespots behind the tentacle bases, and the third and fifth segments, for the noticeable ventral plates (about 20) and a two genera respectively (Hilbig 2000). long narrow posterior. It is yellow to brown, Streblosoma spp. have uncini arran- with red branchiae and orange-brown ged in single straight rows throughout the tentacles (Berkeley and Berkeley 1952). body, not changing into a depressed ring Ecological Information as in Thelepus crispus. They, too, have Range: Type locality is San Francisco, Cali- three pairs of branchiae and notosetae fornia (Hartman 1969). Distribution along the beginning on the first branchial segment, NE Pacific from Alaska south to California. not on the second (Blake 1975). A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: https://oimb.uoregon.edu/oregon-estuarine-invertebrates and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] Local Distribution: Oregon sites include day later. They have five setigers and long Yaquina Bay (Hartman and Reish 1950). first tentacle at 12 days and are juveniles with Coos Bay sites include Pigeon Point and eight setigers by day 26 (McHugh 1993). many stations inside and outside the bay. Juvenile: Habitat: Thelepus crispus attaches its tube Longevity: to the undersides of rocks and shells. Indi- Growth Rate: viduals are found in Coos Bay in empty Food: A suspension and deposit feeder, pholad (= family Pholadidae, boring clams) Thelepus crispus traps detritus particles with burrows. is tentacles and passes food in a mucus film Salinity: Found at salinities of 30 in Coos along tentacle grooves and into the mouth. Bay. Individuals encountered in lower parts Research suggests that Thelepus crispus of bays where salinity is not likely to be re- orients its feeding tentacles in response to the duced. predominating direction and strength of Temperature: currents (Musgrove 1982). Tidal Level: Intertidal. Predators: Associates: Nearly all specimens, from Behavior: Thelepus crispus contains and re- Coos Bay, had the polynoid polychaete, leases brominated aromatic metabolites into Halosydna brevisetosa in their burrows. In sediment surrounding their burrows. Concen- under-rock and mudflat habitats of bays, as- trations of dibromobenzyl alcohol in surface sociates include Cancer oregonensis and sediments (to 6 cm depths) increased with burrowing clams from the genera Adula and proximity to burrows of T. crispus (Lincoln et Penitella. al. 2005). These contaminated sediments Abundance: This species can be fairly can negatively impact the nearby community abundant within its narrow habitat and is one and reduce settlement and recruitment of oth- of the most common local intertidal er polychaetes (e.g. Nereis vexillosa, Woodin terebellids. et al. 1993). Life-History Information Bibliography Reproduction: Terebellid reproductive and 1. BERKELEY, E., and C. BERKELEY. 1952. developmental modes are highly variable. Annelida: polychaeta sedentaria. Canadi- Thelepus crispus is an iteroparous brooder an Pacific Fauna. 9b:1-139. where individuals are continually reproduc- 2. BLAKE, J. A. 1975. Phylum Annelida: