Bradabyssa whiteavesi (McIntosh, 1885) 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 : 89-90

Bradabyssa whiteavesi (McIntosh, 1885) n. comb.

Figures 46 , 47

Brada whiteavesii McIntosh, 1885: 371 –372, Pl. 45, Figs 3 , 4 , Pl. 23A, Figs 9 , 10 .

Type material. New Zealand. Holotype ( BMNH 1885.12.1.264), Queen Charlotte Sound (41°13'00" S, 174°10'00" E), R.V. Challenger, 18 m.

Additional material. New Zealand. Three specimens ( LACM 9558 ), American Museum of Natural History Expedition , R.V. Vema, Cruise 18, Sta. 113 (40.5° S, 174.1° E), Cook Strait, N off Stephens Island, 117 m, 31 Jul. 1962 (complete 13 mm long, 2 mm wide, cephalic cage 2.5 mm long, 40 chaetigers; gonopodial lobes in chaetiger 5).

Description. Holotype (BMNH 1885.12.1.264), complete; body fusiform, whitish, cut transversely towards posterior end ( Fig. 46A ; same features in non-type specimen 47A); 16.5 mm long, 3.8 mm wide, cephalic cage 2 mm long, 20 chaetigers. Papillae covered by medium-sized sediment grains, papillae tips without sediment, probably eroded. Papillae larger dorsally, shorter ventrally; dorsal ones fusiform, tapered, posterior chaetigers with longer papillae; 4–5 transverse series dorsally, 5–6 ventrally.

Anterior end features not observed in holotype. Non-type (LACM 9558) dissected; cephalic tube short, margin smooth. Prostomium low, rounded, eyes not seen. Palps thick, longer than branchiae; palp keels large, rounded. Caruncle barely separating branchial groups ( Fig. 47D ). Lips distorted, dorsal lip reduced, lateral lips well developed, ventral lip reduced. Branchiae cirriform, pale, filaments arranged in several rows, with about 40 filaments per group. Nephridial lobes positioned in the lower lateral base of branchial groups.

Cephalic cage chaetae as long as half body width. Only chaetiger 1 involved in cephalic cage, 4–5 notochaetae and 3–4 neurochaetae per side, most broken.

Anterior margin of first chaetiger papillate ( Fig. 46B ), papillae long, sparse, probably eroded in holotype, longer in non-type specimen ( Fig. 47B ). Chaetigers 1–3 of similar length. Chaetal transition from cephalic cage to body chaetae abrupt; aristate neurospines present from chaetiger 2. Ventral gonopodial lobes pale, in chaetiger 5 ( Fig. 46C ).

Parapodia well developed, lateral. Median neuropodia ventrolateral. Notopodia and neuropodia close to each other. Notopodia with chaetal lobe rounded, with 2–3 basal long papillae, about 1/5 as long as notochaetae anteriorly, longer posteriorly, becoming about 2/3 as long as notochaetae; neuropodia with larger rounded lobes, with 1–2 long basal papillae.

Median notochaetae arranged in short transverse series, most notochaetae multiarticulate capillaries with articles short basally and medially, longer distally ( Fig. 47E ), 5–6 per bundle, as long as half body width. Neurochaetae multiarticulate capillaries in chaetiger 1; posterior chaetigers with aristate neurospines, arranged in short transverse series, 4–5 per bundle. Each neurospine with short rings basally, shorter medially, distally slightly curved, hyaline with long mucro ( Fig. 47F ).

Posterior end truncated, rounded; pygidium with anus ventroterminal, anal cirri absent ( Figs 46A , 47A ).

Variation. Complete additional specimen 13 mm long, 2 mm wide, cephalic cage 2.5 mm long, 40 chaetigers.

Remarks. Bradabyssa whiteavesi (McIntosh, 1885) n. comb. closely resembles B. intoshi (Caullery, 1944) n. comb. Both species have small bodies with about 20 chaetigers, possess dorsal papillae with adhering sand particles and relatively long notopodial papillae. They differ because in B. whiteavesi gonopodial papillae are digitate and parapodial papillae are half as long as notochaetae, whereas in B. intoshi , gonopodial papillae are 8- shaped and notopodial papillae can be two-thirds as long as notochaetae.

The non-type specimen was collected near the type locality but from deeper water. It is slightly smaller but has twice as many chaetigers, and has been included here with hesitation. Addition well preserved material is needed to determine variation in number of chaetigers with depth.

Distribution. New Zealand, in 18–117 m water depth.

Figures

FIGURE 3. Brada granosa Stimpson, 1853. A. Juveniles (USNM 453). B. Non-type specimens (USNM 22851), chaetiger 2, right parapodium, anterior view. C. Same, notochaetal basal, medial and distal regions. D. Same, neurochaetal tips. E. Chaetiger 17, right parapodium, anterior view. F. Same, neurochaetal tips. Scale bars: A: 0.8 mm, B, E: 0.3 mm, C: 80 µm, D, F: 20 µm.

FIGURE 4. Brada granulosa Hansen, 1880, syntypes (ZMUB 2197). A. Largest and smallest syntypes, oblique lateral view, anterior end pointing upwards. B. Largest syntype, anterior end, lateral view (arrow points to gonopodial lobe). C. Another syntype, head, frontal view, branchiae and palps removed (Br: branchial scar, PS: palp scar). D. Same, chaetiger 10, right parapodium, posterior view. E. Same, basal, medial and distal notochaetal regions. F. Chaetiger 3, right parapodium, neurochaetae tips (insets: chaetal tips). G. Chaetiger 11, neurochaetae (inset: chaetal tip). Scale bars: A: 6 mm, B: 0.7 mm, C: 0.5 mm, D: 0.1 mm, E: 40 µm, F: 0.2 mm, G: 110 µm.

FIGURE 9. Bradabyssa mexicana n. sp., holotype (LACM 7228). A. Dorsal view. B. Anterior end, dorsal view, bluish after methyl-green staining. C. Ventral view. D. Head, frontal view, cut open to show branchial scars, palps and branchiae removed, greenish after methyl-green staining (Br: branchial scars, PS: palp scar). E. Chaetiger 10, neurochaetae (inset: neurochaetal tips). Scale bars: A: 0.8 mm, B: 0.3 mm, C: 1.1 mm, D: 0.2 mm, E: 60 µm.

FIGURE 10. Bradabyssa minuta (Amoureux, 1986) n. comb., syntypes (MNHN 834). A. Five syntypes, mostly without globose foraminiferans. B. Three syntypes with globose foraminiferans on tunic. C. Median chaetiger, right parapodium (insets: notochaetal basal regions, neurochaetal tips). Scale bars: A: 0.4 mm, B: 0.3 mm, C: 65 µm.

FIGURE 46. Bradabyssa whiteavesi (McIntosh, 1885) n. comb., holotype (BMNH 1885.12.1.264): A. Dorsal view. B. Anterior region, dorsal view. C. Anterior region, ventral view (arrows point to gonopodial lobes). Scale bars: A: 1.9 mm, B: 0. 8 mm, C: 0.6 mm.

FIGURE 47. Bradabyssa whiteavesi (McIntosh, 1885) n. comb., non-type specimens (LACM 9558), after methyl-green staining: A. Dorsal view. B. Anterior region, dorsal view. C. Anterior region, ventral view (arrow points to right gonopodial lobe). D. Head, frontal view, branchiae, nephridial lobes and palps removed (Br: branchial scars, NL: nephridial lobe, LL: lateral lip, PS: palp scar). E. Chaetiger 10, right parapodium, notochaetal basal, medial and distal regions. F. Same, neurochaetae. Scale bars: A: 1.7 mm, B: 0.3 mm, C: 0.2 mm, D: 0.1 mm, E: 30 µm, F: 120 µm.