Bradabyssa papillata Hartman, 1967

Salazar-Vallejo, Sergio I., 2017, Revision of Brada Stimpson, 1853, and Bradabyssa Hartman, 1967 (Annelida, Flabelligeridae), Zootaxa 4343 (1), pp. 1-98 : 56-57

Bradabyssa papillata Hartman, 1967

Figure 28

Bradabyssa papillata Hartman, 1967: 122 –123, Pl. 37, Fig. C.—Hartman 1978: 168, Fig. 20a–e (redescr.).

Type material. Antarctica. Holotype ( USNM 55544 ) and paratypes ( USNM 55545 ), Scotia Sea , USNS Eltanin , Sta. 1070 (59°08' S, 36°57' W → 59°01' S, 36°50' W), 2815–2818 m, 9–10 Apr. 1964 (paratypes include a complete specimen cut into two sections, and an anterior fragment; complete 62(12+50) mm long, 10 mm wide, cephalic cage 2 mm long in anterior fragment, 53(8+45) chaetigers, regenerating posterior end).

Description. Holotype ( USNM 55544) complete, colourless, long, cylindrical, first four chaetigers swollen, progressively widening then body tapered, last six chaetigers swollen ( Fig. 28A); 70 mm long, 6.5 mm wide, cephalic cage 1 mm long, 59 chaetigers. Body tubercles as 8 transverse series dorsally, alternating in size and position, ventrally 6 alternating series, all of similar size, without sediment cover ( Fig. 28B).

Cephalic hood not exposed in holotype; complete paratype with anterior end exposed ( Fig. 28C). Cephalic hood short, margin smooth. Prostomium low lobe, eyes not seen. Caruncle well developed, pale, slightly eroded, reaching branchial plate margin, lateral ridges and median keel elevated. Palps thick, short, wider basally, not corrugated; palp bases low, pale. Lips damaged, lateral ones thicker; dorsal and ventral lips probably reduced.

Branchiae missing, branchial scars on branchial plate, arranged into two lateral groups, each with over 20 scars; size relative to palps unknown. Nephridial lobes in branchial plate not seen.

Cephalic cage poorly developed, chaetae broken, chaetiger 1 with notochaetae 2/3 as long as notochaetae of chaetiger 2. Chaetiger 1 involved in cephalic cage. Anterior dorsal margin of first chaetiger papillated, papillae minute. Chaetigers 1–3 of similar size, parapodia reduced in chaetiger 1. Chaetal transition from cephalic cage to body chaetae abrupt; chaetiger 2 with neurochaetae thicker. Gonopodial lobes in chaetiger 5 ( Fig. 28D), globular, pale.

Parapodia poorly developed, lateral. Median neuropodia ventrolateral. Notopodia and neuropodia very close to each other. Notopodia short rounded lobes, without papillae; posterior third of the body with bottle-shaped long papillae. Neuropodia better developed, large muscular rounded lobe, smooth, non-papillated.

Median notochaetae arranged in tufts; all multiarticulate capillaries, about 1/5 body width, 2–3 per bundle, articles short basally, medially medium-sized, long distally ( Fig. 28E). Neurochaetae multiarticulate in chaetiger 1, aristate neurospines from chaetiger 2, in median chaetigers 3 neurochaetae per ramus arranged in transverse series, in posterior chaetigers arranged in J-shaped pattern, 4–5 per bundle; each subdistally hyaline, mucronate ( Fig. 28F).

Posterior end swollen (5.5 mm maximal width), pygidium with anus dorsal, rounded triangular dorsal lobe present, anal cirri absent.

Remarks. Bradabyssa papillata Hartman, 1967 resembles B. elinae n. sp. by having 9–10 transverse series of tubercles having markedly different sizes in median chaetigers; they differ, however, because B. papillata has 53–59 chaetigers and no sediment cover, whereas in B. elinae there are fewer chaetigers (27–29) and a thin layer of sediment particles cover the body.

Distribution. Scotia Sea, Antarctica.