Phylum: Annelida Leitoscoloplos pugettensis Class: Polychaeta, Sedentaria, Scolecida A burrowing polychaete worm Order: Family: Orbiniidae, Orbiniinae Taxonomy: In 1957 Pettibone determined dominal region between setigers 15–21 that H. elongatus was a homonym a different (Hartman 1969). Thoracic dorsum flat and species named H. elongatus and was there- ventrum convex. No ventral papillae in poste- fore renamed H. pugettensis (Blake 1980). rior thorax (genus Leitoscoloplos, Day 1977) Haploscoloplos became a junior synonym of (Fig. 1). Scoloplos (for nomenclature see Blake Posterior: Pygidium slightly expanded, 1980) in 1977 and the genus Leitoscoloplos hemispherical). Anus dorsal. Long, slender was erected which now includes all former anal cirri (Scoloplos acmeceps, Fig. 1, John- Haploscoloplos species with pointed thoracic son 1901). setae and without parapodial hooks, includ- Parapodia: Biramous and lateral anteriorly ing L. pugettensis. (family Ordiniidae, Fauchald 1977), dorsal posteriorly (Harman 1969) (Fig. 1). Anterior- Description most podia short. Thorax with small papillar Size: Individuals range in size from 100–200 postsetal lobes (Hartman 1969) (Fig. 3). Ab- mm in length and 3 mm in width (Hartman dominal parapodia supported by acicula (Fig. 1969) with up to 300 setigers (Blake 1996). 5) and lobes become long and leaf-like poste- The specimen examined from Coos Bay was riorly (Johnson 1901) (Fig. 5). Abdominal no- 75 mm long with 136 segments. topodia with subtriangular postsetal lobes Color: When sexually mature, males are (Blake 1996). Abdominal neuropodia with bi- pink and females grey (Blake 1980). fid lobes. Inflated neuropodial flange present General Morphology: Orbiniids can be rec- (Blake 1996). ognized by their body morphology: anterior Setae (chaetae): Simple (not jointed) (family region is firm while the abdominal region is Orbiniidae Fauchald 1977). All slender and fragile, ragged and easily lost and by the pointed: leitos = simple, scoloplos = thorn presence of camerated and crenulated se- (Day 1977). Notosetae and neurosetae finely tae (Blake and Ruff 2007). crenulate (Blake 1996) in thorax (Fig. 4a). Body: Long, slender with 200–300 short Abdominal capillary noto- and neurosetae, as segments (Johnson 1901). Body most in thorax, have few furcate spines (Hartman broad at segments 9–17, narrowing gradual- 1969) (Fig. 4c). ly after segment 200. Eyes/Eyespots: None. Anterior: Prostomium small, acutely Anterior Appendages: None (family Orbini- pointed and conical (genus Leitoscoloplos, idae, Fauchald 1977). Day 1977) and with small palpode at apex Branchiae: Begin on setigers 13–18 (Fig. 2a). Peristomium bears one ring and (Hartman 1969) .Setiger 18 in present speci- width increases rapidly toward the second mens (from Coos Bay). Branchiae small (i.e. segment (Fig. 2a). First segment achaetous short and narrow) anteriorly, becoming flat (Figs. 1, 2). and subdistally inflated, laterally fringed Trunk: Thorax composed of 14–21 (“fimbriated”) and larger posteriorly (Fig. 5) setigers with transition from thoracic to ab- 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. Leitoscoloplos pugettensis. 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, Charles- ton, OR. (Hartman 1969). Abdominal branchiae are ginning on setigers 4–10 (not on all posterior twice as long as notopodial lobes (Blake segments). The body in Paraonidae is not 1996). divided into distinct regions by setae and par- Burrow/Tube: These burrowing poly- apodial shapes, but changes gradually along chaetes do not inhabit permanent burrows the body (not distinctly as in Orbiniidae, Fau- or tubes (Blake and Ruff 2007). chald 1977). A Paraonidae prostomium can Pharynx: Bears eversible proboscis with have a medial antenna, which are lacking in leaf-shaped lobes (Fig. 2b). Orbiniidae. They have branchiae on some Genitalia: median setigers in most species. The para- Nephridia: podia are lateral. Local paraonid genera in- clude: Aricidea, Cirrophorus, Paraonella and Possible Misidentifications Levinsenia (= Tauberia) (Hobson and Banse The order Orbiniida (Fauchald 1977) 1981; Blake and Ruff 2007). includes the families Orbiniidae and Paraon- Orbiniidae genera in the subfamily Pro- idae, the latter comprising smaller species toarciinae are small (less than 20 mm), have (less than 20 mm in length) (Blake and Ruff rounded prostomium, 1–2 asetigerous anteri- 2007). The order is characterized by a lack or segments, two peristomial rings and can of prostomial appendages, maximum of two lack branchiae. Recent research suggests asetigerous anterior segments, a lack of ad- that many Protoarciinae species are simply ditional cephalized segments or palps, sim- juvenile orbiniids (Blake 1996; 2000b). Gene- ple setae and an eversible pharynx that is ra include: either an axial sac or biramous (Fauchald Orbiniella, with two asetigerous anteri- 1977). Members of the family Orbiniidae or segments and no branchiae. Neuropodia have a prostomium and peristomium without have both hooks and capillary setae (Hobson appendages, one to two asetigerous anterior and Banse 1981). Orbiniella nuda is found segments and lateral thoracic parapodia, intertidally in Washington and British Colum- becoming dorsal abdominally. Setae can be bia, amongst gravel and rock. Para- capillary or simple hooks and some species orbiniella, a monotypic northeastern Pacific have brush-topped bifid or furcate setae. genus (Hobson and Banse 1981). Orbiniidae and Paraonidae can be distin- Protoaricia spp. have two asetigerous guished by peristomial rings, where orbiniids segments, are less than 6 mm in length and have one and paraonids have two (Blake have been found in northern California (Blake 2000). 1975). There are several similar families (not Protoariciella differs from Protoaricia by in the order Orbiniida): Ophelidae are short the presence of neuropodial hooks in the ab- and stout and have a strong ventral groove. dominal region (Hobson and Banse 1981). Goniadidae and Glyceridae have palps or Most notosetae are forked. Its branchiae some kind of buccal appendage. Am- begin at setigers 4–5 and continue to setigers pharetidae have retractible tentacles and 28–47. Protoariciella oligoranchia is found in Lumbrineridae have hard jaw pieces and British Columbia (Hobson 1976). hooded hooks among the setae (uncini). Polychaetes in the subfamily Orbini- Among those families which are orb- inae (including L. pugettensis) have only 1 iniids, the Paraonidae are small and often asetigerous anterior segment and its mem- overlooked, they have branchiae occurring bers are usually over 20 mm in length. Local only on maximum of 15–20 segments, be- genera in the Orbiniinae include: 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] Naineris, which has a broadly round- tigers 13–18 in L. pugettensis. ed prostomium (unlike that of Leitoscolo- Ecological Information plos). Naineris dendritica, often found in al- Range: Alaska to southern California gae or in the marine grass (Phyllospadix), (Hartman 1969). occurs inside Coos Bay (Hartman and Reish Local Distribution: In Coos Bay including 1950) and offshore. Naineris quadricuspida South Slough, Shore Acres and offshore. and N. uncinata are found farther north Also Columbia River mouth and Yaquina Bay. (Hobson and Banse 1981). Habitat: Burrows in sandy shores (Johnson Orbinia have pointed prostomium and 1901) in gravelly, silty, fine sands (Parkinson one asetigerous anterior segment (as in L. 1978) or fine mud (Barnard and Reish 1959). pugettensis), but they also have very con- Individuals found in most substrates except spicuous ventral papillae on the posterior for black sulfide mud. Found occasionally thoracic segments, which are lacking in L. with eelgrass or algae, but not as closely as- pugettensis. Orbinia johnsoni is a rocky in- sociated with plant growth as in Naineris tertidal species. (Blake 1975). In Bodega Bay, California, Scoloplos is the genus most likely to most common in sandy mud with a large grain be confused with Leitoscoloplos. Scoloplos size and with little algal (Ulva) cover spp. have a pointed prostomium, one asetig- (Parkinson 1978). erous anterior segment and no ventral tho- Salinity: Found in salinities of 30 in Coos racic papillae. These two genera must be Bay. separated by their setae: Scoloplos have Temperature: Larvae successfully cultured at blunt spines as well as slender pointed se- 14–15˚C (Blake 1980). tae in the thoracic neuropodia. Scoloplos Tidal Level: Near low-water mark (Johnson acmeceps has a few incomplete rows of 1901). Also subtidal, but not as often as curved and ridged uncini in its thoracic neu- Scoloplos in Coos Bay, down to 380 m ropodia. Some of these neuropodia also (Parkinson 1978). have a single post-setal lobe. This species Associates: is found in the Coos Bay and Umpqua estu- Abundance: One of the most common inter- aries, usually subtidally. In California, it is tidal and subtidal benthic polychaetes