Brada inhabilis (Rathke, 1843)

Figure 6

Siphonostoma inhabile Rathke, 1843: 218 –219, Pl. 11, Fig. 13.

Brada inhabilis .— Malmgren 1867: 84.— Haase 1915: 206 –209, Textfig. 9 (partim).— Støp-Bowitz, 1948a: 40 –44, Fig. 11 (syn.); 1948b: 42–44, map.— Pettibone 1956: 565.— Hartmann-Schröder 1971: 377 –378, Fig. 134; 1996:414, Fig. 200.— Jirkov & Filippova 2001: 353, Figs 1–5.— Oug et al. 2011: 14, Figs a–c (repeated from Støp-Bowitz, 1948a).

Brada sublaevis Stimpson, 1853: 32 .— Webster & Benedict 1887: 732 (syn.).

Brada granulata Malmgren, 1867: 194, Pl. 13, Fig. 71, 71A–C.— Théel 1879: 52 –53.— Fauvel 1907: 23.— Moore 1909a: 143.— Haase 1915: 209 –211, Textfig. 10.— Borodin 1929: 28 –36, Pl. 1 (integument and papillae).— Wesenberg-Lund 1950a: 36, 1950b: 85–86.

Material examined. Canadian Arctic Ocean. Eight specimens (USNM 1422402), damaged, Grainger Collection, Creswell Bay, Sta. 62-2014 (72°43.3' N, 94°05' W), 35 m , 25 Aug. 1962 (45–58 mm long, 8–10 mm wide, 20–23 chaetigers). Northeastern Atlantic Ocean. One specimen (ZMUB 11019), off Kvaenangen (60°53'39" N, 21°58'49" E), Norway, Bio. Det., 90 m , Nordgaard, coll. (pale yellowish, 20.5 mm long, 4 mm wide, cephalic cage 0.3 mm long (one neurochaetae), 22 chaetigers). One specimen (ZMUB 25245), R.V. Michael Sars, 1900 Expedition, Sta. 10 (64°53' N, 10°00' E), 630 m , 28 Jan. 1900 (dark grayish, turgid, 32.5 mm long, 10 mm wide, no cephalic cage chaetae left, 22 chaetigers). Two large specimens (ZMUB 34537), off Syd av Vadsø (70°04'24" N, 291°44'59" E), Norway, R.V. Johan Hjort, Sta. 333 , 18 Jun. 1927 (larger used for description; the other 31 mm long, 5.5 mm wide, no cephalic cage chaetae left, 22 chaetigers). Barents Sea, White Sea. Eight specimens (ECOSUR P2899), 20 m, 6 Aug. 1998, A. Filippova, coll. (14–36 mm long, 3.5–5.0 mm wide, cephalic cage chaetae broken, 20–22 chaetigers; black, low, rounded gonopodial papillae in chaetiger 5).

Description. Larger, non-type specimen complete (ZMUB 34537), yellowish, slightly damaged, most chaetae broken; body fusiform, truncate in both ends (Fig. 6A); 34 mm long, 7 mm wide, no cephalic cage chaetae remaining, 22 chaetigers. Papillae very small, globose, arranged in alternating transverse rows, dorsally with 12–13 series per segment, ventrally 7–8; all papillae covered by thin layer of fine sediment particles (Fig. 6B).

Anterior end not exposed (smaller, non-type specimen ZMUB 34537 dissected). Prostomium low dark cone, with four large eyes, color faded away. Caruncle well developed, not reaching the branchial plate posterior margin, though there is a thin pigmented ridge running posteriorly. Palps very thick, sides with darker pigment, deep ciliated furrow; basally with abundant whitish ciliates. Palp keels rounded, low. Lateral lips well developed, thick, darker. Ventral lip reduced. Dorsal lip triangular, directed ventrally.

Branchiae all thick cirriform, sessile on branchial plate, arranged along a single, posterior row (Fig. 6C). Branchiae as long as palps. Nephridial lobes in branchial plate not seen.

Cephalic cage absent; chaetiger 1 without chaetae. Anterior dorsal margin of first chaetiger papillated, triangular, directed ventrally. Anterior chaetigers without especially long papillae. Chaetigers 1–3 decreasing in size posteriorly. Chaetal transition from cephalic cage to body chaetae abrupt; falcate neurospines present from chaetiger 2. Gonopodial lobes present in chaetiger 5 (Fig. 6B).

Parapodia well developed, lateral; median neuropodia ventrolateral. Notopodia and neuropodia close to each other. Notopodia small truncate lobes with 2–3 small, infrachaetal papillae. Neuropodia large truncate rounded lobes surrounded by 1–2 series of papillae (Fig. 6D).

Median notochaetae arranged in short tufts; all notochaetae multiarticulate capillaries, articles medium-sized alternating with longer articles basal- and medially, longer distally (Fig. 6E), 2–4 per ramus, as long as 1/10 body width. Falcate neurospines present from chaetiger 2, arranged in short transverse series, 4–6 per ramus. Each neurospine with very small anchylose articles basally and medially, distally paler; tips blunt, barely curved (Fig. 6F).

Posterior end blunt, rounded; pygidium with anus ventroterminal, vertical slit, with large lateral lobes, without anal cirri.

Variation. Adult specimens 14–58 mm long, 3.5–10.0 mm wide, 20–23 chaetigers.

Remarks. Brada inhabilis was originally described by Rathke from Molde (62°45'23" N, 07°14'19" E), Norway, but the type material, originally deposited in Konigsberg (now Kaliningrad, Russia) was destroyed during World War II. The above described Norwegian material was collected in northern Norway, in what is called the Finmark subprovince, which differs from the southern Norwegian coast, or western Norwegian subprovince (Oug et al. 2010:17). No neotype has been designated thus far.

On the other hand, the record of B. inhabilis by Langerhans (1881:102–103, Fig. 14a–d) corresponds to a Diplocirrus . Pettibone (1954:292–293) included in her synonymies of B. inhabilis, B. sublaevis Stimpson, 1853, B. granulata Malmgren, 1867, and B. granosa Stimpson, 1853 . However, Brada granosa was later accepted by her (Pettibone 1956:565), and is also redescribed herein. The other species regarded as a junior synonym is B. granulata, described from Spitsbergen and Greenland; this synonymy was accepted by Wesenberg-Lund (1950a:36), and by Ushakov (1955:310; 1965:287), whereas B. sublaevis, described from Eastern Canada, has not been recorded since the original description, and because there is no type material available, and should be regarded as indeterminable. Moore (1909a:143) recorded B. granulata from Eastern Canada and stated that it might be the same as B. sublaevis Stimpson, a synonymy that had already been suggested by Webster & Benedict (1887:732); however, they also indicated that because of the short description by Stimpson, “… it would be better to retain Malmgren’s name…” Furthermore, B. granulata is a junior synonym of B. inhabilis according to Støp- Bowitz (1948:40–44). The northwestern Pacific records of B. granulata by Ushakov (1955:310(1965:287), Figs. 115A–C), and Levenstein (1966:45) most likely belong to other species.

Brada inhabilis (Rathke, 1843) and B. kudenovi n. sp. are very similar as both species have abundant, small papillae throughout the body surface, notochaetae with alternating short and long articles, and neurospines with thin anchylose articles. They differ in several features, however: B. inhabilis body is tan, with 20–23 chaetigers, neuropodial lobes projecting, and 3–4 notochaetae per bundle, whereas B. kudenovi has a whitish body with 25–26 chaetigers, neuropodial lobes flat, barely projecting, and 1–2 notochaetae per bundle.

Distribution. Arctic and subarctic environments in shallow to deep mostly North Atlantic waters.