Bradabyssa pilosa (Moore, 1906) n. comb.

Figure 41

Brada pilosa Moore, 1906: 231 –233, Pl. 10, Figs 14–17.—Moore 1908: 357.—Loi 1980: 137.

Brada villosa.—Hartman 1969: 281–282, Figs 1–5.—Hobson & Banse 1981: 58 Fig. 11b (non Rathke, 1843).

Type material. Northeastern Pacific Ocean. Two syntypes (ANSP 2132, originally regarded as co-types), Alaskan Salmon Commission 1903, R.V. Albatross, Sta. 4251 (57°30' N, 133°30' W), Stephens Passage, Alaska, 362 m, rocks, 14 Jul. 1903, H. Heath, coll. One syntype (CAS 185), Alaskan Salmon Commission 1903, R.V. Albatross, Sta. 4258, Lynn Canal, Funter Bay, Clear Point, Alaska, 549–573 m, mud, 23 Jul. 1903, H. Heath, coll. (anterior fragment 14.5 mm long, 4 mm wide, cephalic cage 2 mm long, 17 chaetigers).

Additional material. Alaska. One specimen (CAS 168302), Alaskan Salmon Commission 1903, R.V. Albatross, Sta. 4258, Lynn Canal, Funter Bay, Clear Point, Alaska, 549–573 m, mud, 23 Jul. 1903, H. Heath, coll. (complete, 18 mm long, 3.5 mm wide, cephalic cage 2 mm long, 26 chaetigers). Two anterior fragments (ANSP- 2131), Alaskan Salmon Commission 1903, R.V. Albatross, Sta. 4235, vicinity of Yes Bay, 238–353 m, mud, 8 Jul. 1903, H. Heath, coll. (anterior end exposed; partially dried-out). One anterior fragment (ANSP 2133), Alaskan Salmon Commission 1903, R.V. Albatross, Sta. 4258, Lynn Canal, 549–573 m, mud, 23 Jul. 1903, H. Heath, coll. (17.5 mm long, 3.5 mm wide, cephalic cage 2.5 mm long, 24 chaetigers; dissected to observe anterior end; one posterior parapodium removed for chaetae). British Columbia. One specimen (ANSP 2134), broken into two pieces, Alaskan Salmon Commission 1903, R.V. Albatross, Sta. 4198, Halibut Band, Gulf of Georgia, B.C., Canada, 287–420 m, mud, 20 Jun. 1903, H. Heath, coll. (17.5 mm long, 3 mm wide, cephalic cage broken, 33 chaetigers; body maculated, nephridial lobes in chaetiger 5). Oregon. One specimen (USNM 248201), off SW mouth Columbia River (45°45' N, 125°09' W), shrimp trawl, 1647 m (bottom temp. 2.6° C, salinity 34.472‰) (Chaetae of chaetiger 1 2.0–2.5 times longer than following ones; gonopodial lobes in anterior margins of chaetiger 4 and 5). One damaged specimen (SMF 15323), off Oregon, Cascadia Margin, R.V. Sonne, cruise 109/2, Sta. TVG- 110 (44°39.950' N, 125°05.791' W → 44°40.225’ N, 125°05.841’ W), 602–611 m, seep (22 mm long, 2.5 mm wide, cephalic cage 5 mm long, 28 chaetigers, gonopodial lobe in chaetiger 5; papillae tiny, abundant, with fine sediment, forming globose structures, most tips eroded; first neurospines in chaetiger 3). California. One anterior fragment (ANSP 3271), R.V. Albatross, Sta. 4326, off Point La Jolla, California, 445–512 m, mud, 8 Mar. 1904 (11.5 mm long, 2 mm wide, cephalic cage 3.8 mm long, 21 chaetigers; gonopodial lobes in chaetiger 5; body with abundant sand grains cover). Five specimens (LACM 3165), 0.3 km from Redondo Pier (33°50.3' N, 118°23.6' W), 40 m, black mud, 25 Jun. 1955 (10–22 mm long, 2.2–5.0 mm wide, cephalic cage 1.5–2.2 mm long, 31–37 chaetigers; four with body anteriorly swollen, posteriorly narrowed; specimens smaller than 16 mm long without gonopodial papillae). One specimen (USNM 288027), off Santa Cruz Island, DOWP Deep submersible dive 1- 1935 (33°56' N, 119°38.7' W), 9 Mar. 1970, C.E. Roper coll. Four specimens (ECOSUR 2901), Alvin Dive 3486, off San Clemente, Seep (32°13.55' N, 117°42.62' W), 1800 m. 16 Oct. 1999, E. Escobar coll. Baja California, Mexico. One specimen (LACM 1694), 4.8 km N off Isla San Martin (30°31'00" N, 116°10'15" W), 75 m, sand, 3 Mar. 1949 (16 mm long, 2 mm wide, cephalic cage 1.2 mm long, 36 chaetigers; gonopodial lobes in chaetiger 5).

Description. Syntypes of Brada pilosa (ANSP 2132) complete; body pale to whitish, fusiform, anteriorly blunt, tapered posteriorly, bent ventrally (Fig. 41A); 19–31 mm long, 3–5 mm wide, cephalic cage 3 mm long (smaller one slightly damaged), 28–30 chaetigers. Papillae completely covered by fine sediment particles, especially basally, but papillae not forming tubercles. Papillae long, fusiform (by sediment accumulation), mucronate, larger dorsally, smaller ventrally (Fig. 41B), not covering intersegmental areas nor interparapodial spaces, in 12–14 series in anterior chaetigers (chaetiger 10), but about 10 in smaller specimens.

Anterior end observed by dissecting another specimen (ANSP 2133). Cephalic tube short, margin smooth. Prostomium low rounded lobe, eyes faintly pigmented. Palps long, very thick, with longitudinal furrow, 1.5 times longer than branchiae; palp keels low, rounded. Caruncle separating branchiae into two lateral groups, with median keel and two lateral ridges, keel larger, more swollen. Dorsal lip reduced; lateral lips larger; ventral lip retracted.

Branchiae cirriform, sessile on branchial plate, separated into two lateral groups, filaments arranged in several rows, up to 30 filaments per group (Fig. 41C). Nephridial lobes not seen.

Cephalic cage present, chaetae as long as 1/10 body length or 3/5 body width. Only chaetiger 1 involved in cephalic cage; chaetae arranged in short lateral series, each with 4–5 chaetae.

Anterior margin of first chaetiger papillated, papillae long, abundant. Anterior chaetigers without especially long papillae. Chaetigers 1–3 progressively shorter. Chaetal transition from cephalic cage to body chaetae abrupt; aristate neurospines present from chaetiger 2. Ventral gonopodial lobes in chaetiger 5, each digitate, tapered (Fig. 41D).

Parapodia lateral; median neuropodia ventrolateral. Notopodia and neuropodia close to each other (Fig. 42E). Notopodia with chaetal lobe rounded, with 2 inferior long papillae, about 1/3 as long as notochaetae; neuropodia with larger rounded lobe, with 4–5 inferior long papillae; notopodial lobes rounded, short.

Chaetae dissected from another specimen (ANSP 2133). Median notochaetae arranged in short transverse series, all notochaetae multiarticulate capillaries with articles short basally, medium-sized medially, longer distally, 6–7 chaetae per bundle, as long as 1/3 body width. Neurochaetae multiarticulate capillaries in chaetiger 1; posterior chaetigers with straight aristate neurospines, arranged in a curved pattern, 6–7 per bundle. Each neurospine with short rings basally, become shorter medially, distally hyaline with long, straight mucro (Fig. 41F).

Posterior end rounded, pygidium with anus terminal, anal cirri absent.

Variation. Additional specimens 10–22 mm long, 2–5 mm wide, cephalic cage 1.2–5.0 mm long, 21–37 chaetigers.

Remarks. The holotype (USNM 5512) was not found, and may be lost; therefore, the type specimens are regarded as syntypes.

Bradabyssa pilosa (Moore, 1906) n. comb. resembles other species in the “ villosa ” group because its papillae are covered by fine sediment particles. However, B. pilosa differs from the two other species in the subgroup (B. kirkegaardi n. sp. and B. monnioti n. sp.) because its papillae are shorter. Furthermore, B. pilosa differs from B. villosa (Rathke, 1843) mainly in the abundance of dorsal papillae, as stated by Støp-Bowitz (1948c:67). Moore (1906:232) indicated that his new species differed by having 8–12 irregular transverse series of papillae per segment, whereas B. villosa has only 3–4 series of papillae. However, Pettibone (1954:290) regarded both species as synonyms, and this view was followed in more recent studies (Blake 2000:5).

Hartman (1969:282) kept the synonymy but she hesitated about it, and indicated that B. villosa has “… coarser papillae, numering (sic) 3–4 per row…” (this should read “… coarser papillae in 3–4 rows …”). However, as previously indicated herein, the individual papillae profile can be altered due to sediment abrasion during either collecting or sample sieving, or even due to poor preservation; unabraded papillae are basally thicker, rounded and mucronate, but once the sediment is removed, they appear filiform. This difference can be seen even in the same specimen if it has been folded, thus providing evidence of this lateral gradation. The specimens from California (ANSP-3271) have larger sand particles on the body but other features are similar to the Alaskan material.

One specimen (SMF 15323) collected off Oregon had neurospines from chaetiger 3; neurospines are fragile but despite its damaged condition, it might be a different species and is included here with some hesitation.

Distribution. Alaska to Southern California, in subtidal depths, in rock to muddy bottoms of up to 600 m water depth.