Bradabyssa harrisae, 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 : 64-65

Bradabyssa harrisae n. sp.

Figure 32

Type material. Northeastern Atlantic Ocean. Norway. Holotype ( LACM 9552 ), Hardangerfjorden (60°10'00" N, 06°00'00" E), Sta. H 08-62, 126– 186 m, 22 Oct. 1958 . One paratype ( LACM 9553 ), Hardangerfjorden (60°10'00" N, 06°00'00" E), Sta. near Z-106, 12 Nov. 1958 (no further data) (15 mm long, 2 mm wide, cephalic cage 1.5 mm long, 35 chaetigers; dorsal papillae long, filiform, of similar size, with abundant fine sand, forming 4–5 series per segment, without gonopodial lobes).

Additional material. Northeastern Atlantic Ocean. Norway. An anterior fragment ( LACM 9554 ), Hardangerfjorden (60°10'00" N, 06°00'00" E), Sta. Z 05-65, 195 – 135 m, 18 Oct. 1965 (no further data) (23 mm long, 4 mm wide, cephalic cage 3 mm long, 30 chaetigers; dorsal papillae long, filiform, with abundant sand grains in base and stem, 5–6 series per segment, nephridial lobe in chaetiger 5). A posterior fragment ( LACM 9555 ), Hardangerfjorden (60°10'00" N, 06°00'00" E), Sta. 83-58, 126 – 186 m, 22 Oct. 1958 (no further data) (posterior chaetigers with large sand particles; pygidium with middorsal rounded lobe and radial muscular lobes, slightly incrusted with fine sediment grains). One specimen ( USNM 1073357 ), broken in two, posterior region damaged, Vanvikan (66º33'33" N, 10º12'14" E), Trondheim Fjord, 18 Feb. 2003, F. Pleijel, coll. (12 mm long, 2 mm wide, cephalic cage 1.5 mm long, 30 chaetigers; 6 transverse series of papillae in chaetiger 10; gonopodial lobes pale in chaetiger 5). Sweden. Two complete specimens ( LACM 9556 ), Tjarno, L.H. Harris, coll. (14.5–17.0 mm long, 1.7–2.5 mm wide, cephalic cage 1.8–2.0 mm long, 36–38 chaetigers; gonopodial lobes in chaetiger 5).

Description. Holotype (LACM 9552) complete, mature female; body pale, slightly fusiform, anteriorly blunt, tapered posteriorly, posterior region regenerated ( Fig. 32A ); 33 mm long, 4 mm wide, cephalic cage 3 mm long, 38 chaetigers. Tunic papillated; papillae long, basally covered with fine sand grains, papillae tips free from sediment. Papillae larger dorsally, shorter ventrally, in 5–6 transverse series per segment.

Anterior end exposed. Cephalic tube short, margin smooth. Prostomium low, rounded lobe, eyes not seen. Palps pale, thick, with longitudinal furrow, about twice as long as branchiae ( Fig. 32C ); palps keels low, rounded. Caruncle separating branchiae into two lateral groups, with median keel and two lateral ridges, keel large, swollen. Dorsal lip reduced; lateral and ventral lips well developed.

Branchiae cirriform, pale, sessile on branchial plate, separated into two lateral groups, filaments arranged in several rows, up to 100 filaments per group. Nephridial lobes not seen.

Cephalic cage chaetae as long as ¾ body width. Only chaetiger 1 involved in cephalic cage; chaetae arranged in short lateral series, with 6 notochaetae and 4 neurochaetae per ramus.

Anterior margin of first chaetiger papillated, papillae long, sparse, eroded in holotype, better preserved in paratype ( Fig. 32B ). Chaetigers 1–3 of similar length. Chaetal transition from cephalic cage to body chaetae abrupt; aristate neurospines present from chaetiger 2. Gonopodial lobes pale, digitate, in chaetiger 5 ( Fig. 33C, D ).

Parapodia well developed, lateral. Median neuropodia ventrolateral. Notopodia and neuropodia close to each other. Notopodia with chaetal lobe rounded, with 3–4 inferior basally swollen papillae, about one-third to half as long as notochaetae ( Fig. 33E ); neuropodia with larger rounded lobe, with 6–8 inferior, long papillae, basally swollen; notopodial lobes rounded, short.

Median notochaetae arranged in short transverse series, most notochaetae multiarticulate capillaries with articles short basally, medially medium-sized, long distally, 5–6 chaetae per bundle, as long as 1/4 body width. Neurochaetae multiarticulate capillaries in chaetiger 1; posterior chaetigers with aristate neurospines, arranged in short transverse series, 5–6 per bundle. Each neurospine with short anchylose articles basally, become shorter medially, distally hyaline with long mucro ( Fig. 33E , inset).

Posterior region in regeneration; pygidium conical, truncate, anus terminal, anal cirri absent.

Variation. Paratype 15 mm long, 2 mm wide, cephalic cage 1.5 mm long, 35 chaetigers; other specimens 12–23 mm long, 1.7–2.5 mm wide, cephalic cage 1.5–3.0 mm long, 30–38 chaetigers.

Remarks. Bradabyssa harrisae n. sp. specimens were originally confused with B. villosa (Rathke, 1843) n. comb. (see below). They differ in the relative number of chaetigers and especially the relative number of transverse series of dorsal papillae, such that there are species that are more similar to B. harrisae n. sp. than B. villosa , as indicated in the key above. Several of these similar species possess sand particles on the dorsal papillae and bodies with 35–38 chaetigers; B. harrisae differs from all of these because it has 6–8 transverse series of papillae per segment, whereas the others have only 3–4 transverse series of papillae.

Etymology. The species is named after my good friend and teacher, Leslie H. Harris, from the Los Angeles Museum, in recognition of her enormous experience working on polychaetes and to acknowledge her and her husband’s, David Ocker, generosity towards me and several of my colleagues, and particularly as she collected some of the specimens employed for this description.

Distribution. Norway and Sweden, up to 186 m depth.

Figures

FIGURE 32. Bradabyssa harrisae n. sp. A. Holotype (LACM 9552), right lateral view. B. Paratype (LACM 9553), anterior end, dorsal view. C. Holotype, anterior end, ventral view (arrows point to gonopodial lobes). D. Same, enlarged (arrows point to gonopodial lobes). E. Chaetiger 11, right parapodium, posterior view (inset: neurochaetal tips). Scale bars. A: 1.2 mm, B: 0. 3 mm, C: 0.7 mm, D: 0.2 mm, E: 230 µm.

FIGURE 33. Bradabyssa hartmanae n. sp.: A. Holotype (SIORAS 866), dorsal view. B. Same, anterior end, dorsal view. C. Paratype (ECOSUR 185), prostomium with branchiae and palps removed, frontal view (1 – 4: branchial scars, PS: palp scar). D. Holotype, anterior end, ventral view. E. Paratype (ECOSUR 185), chaetiger 6, left parapodium, anterior view (No: distal notochaetal region, Ne: neurochaetal tip). Scale bars: A: 1 mm, B: 0.25 mm, C: 0.1 mm, D: 0.27 mm, E: 150 µm.