Bradabyssa elinae, Salazar-Vallejo, 2017

Salazar-Vallejo, Sergio I., 2017, Revision of Brada Stimpson, 1853, and Bradabyssa Hartman, 1967 (Annelida, Flabelligeridae), Zootaxa 4343 (1), pp. 1-98 : 43-45

Bradabyssa elinae n. sp.

Figure 21

Brada mammillata .— Hartman 1953: 51 (non Grube, 1877).

Type material. Sud-central Atlantic Ocean. Holotype ( SMNH 55750 ) and paratype ( SMNH 55750 b), Falkland ( Malvinas) Islands, Port Louis , Swedish South Polar Expedition 1901–03, Sta. 42 (51°33' S, 58°09' W), 8 m, mud with shells , 26 Aug. 1902 (paratype previously dissected, 19.5 mm long, 3 mm wide, cephalic cage 1.5 mm long, 29 chaetigers). One paratype ( SMNH 55751 ), Falkland ( Malvinas) Islands, Port Louis , Greenpatch , near bridge, Swedish South Polar Expedition 1901–03, Sta. 44 (51°33' S, 58°10' W), 7 m, gravel, algae , 28 Aug. 1902 (23 mm long, 4 mm wide, no cephalic cage chaetae left, 27 chaetigers).

Description. Holotype (SMNH 55750) complete, pale, cylindrical, slightly tapered posteriorly, blunt in both ends ( Fig. 21A ); 23.5 mm long, 3 mm wide, cephalic cage chaetae broken, 28 chaetigers. Papillae with abundant fine sediment particles, cirriform, capitate, with sediment basally, appearing conical, arranged in 6–8 transverse series per segment, dorsally larger with a median belt with 5 larger rounded soft tubercles per segment ( Fig. 21B ), continuing to end of body, each with 4–5 distal cirriform processes; ventral papillae smaller, with basal sediment, appearing conical.

Anterior end observed in paratype (SMNH 55750b). Cephalic hood not exposed. Prostomium low cone, eyes not seen. Caruncle pale, wide, not reaching branchial plate margin. Palps pale, massive; palp keels rounded, low, pale. Lips not seen, damaged by dissection. Branchiae cirriform, sessile on slightly projected protuberance, arranged in concentric rows, separated into two groups, each with about 50 filaments. Branchiae about as long as palps. Nephridial lobes on branchial plate not seen.

Cephalic cage present in paratype (SMNH 55751), chaetae as long as one-half body width. Chaetigers 1–2 involved in cephalic cage, chaetae arranged in short lateral series; chaetigers 1–2 with 3 notochaetae and 3 neurochaetae.

Anterior dorsal margin of first chaetiger papillated. Chaetigers 1–3 slightly decreasing in size posteriorly. Chaetal transition from cephalic cage to body chaetae abrupt; aristate neurospines present from chaetiger 2. Gonopodial lobes present in chaetiger 5, pale ( Fig. 21C , better developed in SMNH 55751).

Parapodia well developed, lateral; median neuropodia ventrolateral ( Fig. 21D ). Notopodia and neuropodia distant to each other. Notopodia low conical lobes with 3 infrachaetal cirriform papillae. Neuropodia larger, rounded projected lobes, with 8 long marginal papillae.

All notochaetae multiarticulate capillaries, articles short basally and medially, becoming medium-sized and long distally ( Fig. 21E ); notochaetae of median chaetigers arranged in short longitudinal series with 4–5 chaetae per bundle, as long as half body width. Neurochaetae multiarticulate capillaries in chaetiger 1; aristate neurospines from chaetiger 2, arranged in transverse series to end of body, 4 per bundle. Each neurospine with medium sized rings basally, becoming shorter medially; distally hyaline, aristate, curved, most aristae broken ( Fig. 21F ).

Posterior end blunt, contracted in holotype ( Fig. 21G ); paratype with pygidium with anus terminal, muscular ring, anal cirri absent.

Variation. Paratypes 19.5–23.0 mm long, 3–4 mm wide, cephalic cage 1.5 mm long, 27–29 chaetigers.

Etymology. This species is named after Elin Sigvaldadóttir, former curator of worms in the Swedish Museum of Natural History, Stockholm, in recognition of her kind support of my research activities and of my fellow colleagues in Mexico.

Remarks. Bradabyssa elinae n. sp. may be confused with B. mammillata (Grube, 1877) n. comb. as both have large dorsal globular tubercles. They differ because B. elinae has a slender, soft body, whereas B. mammillata is thicker and stiff, and because B. elinae possesses aristate neurospines with medium-sized rings, whereas in B. mammillata they have very short rings of similar length.

Distribution. Malvinas (Falkland) Islands, in shallow water.

Figures

FIGURE 21. Bradabyssa elinae n. sp. A. Holotype (SMNH 55750), oblique, left lateral view. B. Anterior end, dorsal view. C. Anterior end, ventral view (arrows point to gonopodial lobes). D. Paratype (SMNH 55751), chaetiger 16, left parapodium, anterior view. E. Same, notochaetal basal, medial and distal regions. F. Same, neurochaetae (inset: chaetal tip, arista twisted). G. Holotype (SMNH 55750), posterior end, dorsal view. Scale bars: A: 1.5 mm, B: 0.6 mm, C: 0.7 mm, D: 150 µm, E: 70 µm, F: 130 µm, G: 0.5 mm.