Bradabyssa annenkovae Salazar-Vallejo 2017, n. comb.

Bradabyssa annenkovae (Buzhinskaja, 2001) n. comb.

Figure 20

Brada arctica Annenkova-Chlopina, 1922: 40.

Brada annenkovae Buzhinskaja, 2001: 60, repl. name.

Type material. Russian Arctic Ocean. Lectotype and paralectotype (ZIRAS 26263), Laptev Sea, off Northern Siberia Islands, R.V. Zarya, Sta. 50 (77°20.5' N, 138°47' E), 38 m, mud, large zoological trawl, 10 Sep. 1901 (largest selected as lectotype, smallest 24 mm long, 5 mm wide, cephalic cage 3 mm long, 24 chaetigers, gonopodial lobe in chaetiger 5, 4 transverse series of papillae per segment). Paralectotypes, 10 complete plus one anterior and other posterior fragments: three paralectotypes (ZIRAS 26259), one complete, an anterior fragment, and a posterior fragment, Russian Polar Expedition 1900–1903, R.V. Zarya, no further data (complete 25 mm long, 9 mm wide, cephalic cage 1 mm (broken), 21 chaetigers, gonopodial lobe in chaetiger 5, 4 transverse series of papillae); three complete paralectotypes (ZIRAS 26260), Laptev Sea, R.V. Zarya, Sta. 49 (75°42' N, 124°41' E), 51 m, mud, large zoological trawl, 6 Sep. 1932 (11–28 mm long, 2–6 mm wide, cephalic cage 1.5–3.0 mm, 22–26 chaetigers, gonopodial lobe in chaetiger 5, not seen in smallest specimen, 4 transverse series of papillae); one paralectotype (ZIRAS 26261), Laptev Sea, R.V. Zarya, Sta. 49 (75°42' N, 124°41' E), 51 m, mud, large zoological trawl, 6 Sep. 1932 (18 mm long, 5 mm wide, cephalic cage 3 mm, 26 chaetigers, gonopodial lobe in chaetiger 5, 4 transverse series of papillae); one paralectotype (ZIRAS 26262), Laptev Sea, R.V. Zarya, Sta. 49 (75°42' N, 124°41' E), 51 m, mud, large zoological trawl, 6 Sep. 1932 (26 mm long, 6 mm wide, cephalic cage 2.5 mm long, 24 chaetigers, gonopodial lobe in chaetiger 5, 4 transverse series of papillae); one paralectotype (ZIRAS 26264), Laptev Sea, R.V. Zarya, Sta. 49 (75°42' N, 124°41' E), 51 m, mud, large zoological trawl, 6 Sep. 1932 (32 mm long, 8 mm wide, cephalic cage 3.5 mm, 24 chaetigers, gonopodial lobe in chaetiger 5, 4 transverse series of papillae; anterior end dissected for details); one paralectotype (ZIRAS 26265), partly dehydrated, Laptev Sea, R.V. Zarya, Sta. 49 (75°42' N, 124°41' E), 51 m, mud, large zoological trawl, 6 Sep. 1932 (13 mm long, 3 mm wide, cephalic cage 2.5 mm long, 24 chaetigers, gonopodial lobe in chaetiger 5, 4 transverse series of papillae).

Description. Lectotype complete (ZIRAS 26263), pale brownish, fusiform, wider anteriorly, tapered posteriorly, blunt in both ends (Fig. 20A, B); several parapodia previously removed; 38 mm long, 8 mm wide, cephalic cage 2 mm (broken), 22 chaetigers. Papillae with fine sediment particles forming a thin layer over the body. Papillae globose anteriorly, larger, bell-shaped posteriorly, capitate, with sediment concentrated basally (medially and distally cover eroded), arranged in 4 transverse series per segment (rarely five), becoming larger and about 2–3 series in posterior chaetigers; papillae shorter ventrally, with basal sediment, rounded, larger in posterior chaetigers.

Anterior end dissected. Cephalic hood not exposed. Prostomium low dark cone, eyes not seen. Caruncle dark, wide basally, reaching branchial plate margin. Palps dark, massive; palp keels rounded, low, dark. Dorsal lip reduced, rounded; lateral lips thicker, larger, fused; ventral lip reduced, damaged during dissection.

Branchiae cirriform, sessile on slightly projected protuberance, separated into two groups, each with about 70 filaments arranged in concentric series (Fig. 20C). Branchiae about as long as palps. Nephridial lobes present on the lateral external base of branchial region, with two lobes, larger distally darker.

Cephalic cage present (broken in lectotype), chaetae as long as 1/10 body length, or about one-half body width. Chaetigers 1–2 involved in cephalic cage, chaetae arranged in a short lateral series; chaetigers 1 with 12 and chaetiger 2 with 8 notochaetae (chaetiger 1 with 10 neurochaetae).

Anterior dorsal margin of first chaetiger papillated. Chaetigers 1–3 of similar length. Chaetal transition from cephalic cage to body chaetae abrupt; aristate neurospines from chaetiger 2. Gonopodial lobes whitish, digitate, present in chaetiger 5.

Parapodia well developed (Fig. 20D), lateral; median neuropodia ventrolateral. Notopodia and neuropodia distant to each other. Notopodia low conical lobes with 3 infrachaetal globose papillae. Neuropodia larger, rounded projected lobe, with 5–6 long marginal globose papillae.

All notochaetae multiarticulate capillaries (most broken), articles short basally and medially, becoming long distally; notochaetae of median chaetigers arranged in short longitudinal series with 7–8 chaetae per bundle, as long as 1/3 body width. Neurochaetae multiarticulate capillaries in chaetiger 1; aristate neurospines from chaetiger 2, arranged in an oblique series to end of body, 6 per bundle. Each neurospine with medium sized rings basally, becoming shorter medially; distally hyaline, aristate, curved, most aristae broken.

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

Variation. Complete paralectotypes 11–32 mm long, 2–9 mm wide, cephalic cage 1.0– 3.5 mm long, 21–26 chaetigers.

Type locality. Off Northern Siberia Islands, Arctic Ocean.

Remarks. Brada arctica Annenkova-Chlopina, 1922 was very briefly described. Hartman (1959) regarded it as a junior homonym of Trophonia arctica Hansen, 1880, which in turn has been regarded as a junior synonym of B. villosa (Rathke, 1843) by Haase (1915), whereas B. arctica Annenkova-Chlopina, 1922 was regarded as a junior synonym of B. villosa by Jirkov & Filippova (2001:357). However, the type material was apparently not examined by the latter, and there are several differences that warrant an independent status. Buzhinskaja (2001) reached the same conclusion and proposed a replacement name because it was a junior homonym of B. arctica (Hansen, 1882) (ICZN 1999, Art. 60.1).

Bradabyssa annenkovae (Buzhinskaja, 2001) n. comb. closely resembles B. grangieri n. sp. because both have dorsal tubercles of similar size, and bodies with few total chaetigers (19–26). They differ because in B. annenkovae gonopodial lobes are pale and neuropodia have 4–5 basal papillae, whereas in B. grangieri gonopodial lobes are dark, and neuropodia have 6–8 basal papillae.

Distribution. Laptev Sea, Russian Arctic Ocean, in shallow water (38–51 m), in muddy bottoms.