Bradabyssa grangieri, 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 : 45-48

Bradabyssa grangieri n. sp.

Figures 22 , 23

Brada villosa .— Haase 1915: 203–206, Textfig. 8.— McIntosh 1915: 104–106, Pl. 95, Fig. 12 , Pl. 96, Figs 6–6c , 12 , Pl. 102, Figs 2–2a (partim, non Rathke, 1843).— Chamberlin 1920: 22; McIntosh 1915: 104–106, Pl. 95, Fig. 12 , Pl. 96, Figs 6–6c , 12 , Pl. 102, Figs 2–2a (partim, non Rathke, 1843).

Type material. Arctic Ocean, Canada. Holotype ( USNM 1422382), and 11 paratypes USNM 1422383), most without sediment particles, R.V. Resolute, Cornwallis Island, Sta. 4006 (74º39.1' N, 94º15.7' W), B25, 5 m, mud, otter trawl, 17 Jul. 1962, E.H. Grangier, coll. (paratypes 32–58 mm long, 5–9 mm wide, cephalic cage 3.5 mm long in one paratype, broken in most, 19–26 chaetigers; gonopodial papillae dark, digitate, in chaetiger 5; some with ochraceous or pale brown tunic remains, posterior tubercles slightly larger than median ones).

Additional material. Arctic Ocean, Canada. One specimen ( USNM 1422384 ), juvenile, R.V. Resolute , Wellington Bay , Banks Island , Cambridge Bay, Sta. 7015 (69º24.3' N, 106º19.5' W) , 20 m, mud, otter trawl, 25 Jul. 1962, E.H. Grangier, coll. (12.5 mm long, 4.2 mm wide, cephalic cage 2 mm long, 24 chaetigers; anterior end exposed; gonopodial papillae in chaetiger 5, digitate, tip dark; median chaetigers with 5 notochaetae and 6 neurochaetae per bundle). Four specimens ( USNM 1422385 ), complete, R.V. Resolute, Banks Island, Prince of Wales Strait, Sta. 1101 (72º53' N, 118º01' W) , 4 m, mud, 24 Jul. 1962, E.H. Grangier, coll. (16–19 mm long, 5 mm wide, cephalic cage 2–3 mm long, 23–24 chaetigers). Eight specimens ( USNM 1422386 ), without posterior region, R.V. Resolute, Prince of Wales Strait, Banks Island, Sta. 1106 (74º06' N, 119º55' W) , 12 m, mud and sand, otter trawl, 26 Jul. 1962, E.H. Grangier, coll. Four specimens ( USNM 1422387 ), two complete, R.V. Resolute, Eureka, Slidre Fjord , Ellesmere Island, Sta. 3001 (80º00' N, 86º00' W), B24, 12 – 20 m, mud, 24 Jul. 1962, E.H. Grangier, coll. (complete ones 28–30 mm long, 7–8 mm wide, cephalic cage 3.5–4.0 mm long, 25–26 chaetigers; one with copepod parasite egg-bag visible in anterior body opening). One specimen ( USNM 1422388 ), R.V. Resolute, Eureka, Slidre Fjord , Ellesmere Island, Sta. 3003 (79º58' N, 85º35' W), B50, 10 – 12 m, mud, 5 Aug. 1962, E.H. Grangier, coll. (32 mm long, 10 mm wide, cephalic cage 4 mm long, 24 chaetigers; parasite egg-bag visible in anterior body opening). One specimen ( USNM 1422389 ), R.V. Resolute, Cornwallis Island, Sta. 4006 (74º39.1' N, 94º15.7' W), B15, 8 m, mud and rocks, otter trawl, 13 Jul. 1962, E.H. Grangier, coll. (34.5 mm long, 9 mm wide, cephalic cage broken, 25 chaetigers). Six specimens ( USNM 1422390 ), four complete, R.V. Resolute, Prince of Wales Strait, Sta. 1101 (72º53' N, 118º01' W) , 4 m, mud, 24 Jul. 1962, E.H. Grangier, coll. (complete ones 20–24 mm long, 5.5–6.0 mm wide, cephalic cage 2–3 mm long, 23–24 chaetigers; tunic variably removed, one specimen completely without it). Barents Sea. Five specimens (HDMSU 29.04.1927), R.V. Persey, Sta. 12-633 (71.3° N, 38° E), Agassiz trawl, 238 m, sandy mud, 29 May 1927 (body fusiform, rounded or tapered towards both ends, or anteriorly swollen, posteriorly tapered in a cylindrical cauda, 20–37 mm long, 5–8 mm wide, cephalic cage 3.0– 3.5 mm long (4–5 notochaetae, 3–4 neurochaetae), 21–25 chaetigers, gonopodial lobe in chaetiger 5 (short digitate, slightly mucronate), 6–9 transverse series of dorsal papillae per segment (larger anteriorly, laterally and in posterior chaetigers; middorsal papillae fusiform, basally thin, larger papillae globose, mucronate). White Sea. One specimen (ECOSUR P2900), 20 m, 6 Aug. 1998, A. Filippova, coll. (26 mm long, 6 mm wide, cephalic cage chaetae broken, 22 chaetigers; black, low, conical gonopodial papillae in chaetiger 5). Northwestern Atlantic Ocean. Anterior fragment ( ANSP 2856 ), halfway between Cape Mugford and Hebron, Labrador, Canada , 110 m, mud and sand, 23 Aug. 1908, O. Bryant, coll.

Description. Holotype (USNM 1422382) complete, dark brown, tunic ochraceous, eroded from most of body, present in a few anterior and posterior segments and laterally ( Fig. 22A ). Body subcylindrical, tapered posteriorly, blunt in both ends; 49 mm long, 8 mm wide, cephalic cage chaetae broken, 26 chaetigers.

Integument papillated, with thin tunic with fine sediment particles forming a thin layer on body. Tubercles globose throughout body, of similar size, larger dorsally ( Fig. 22B ), smaller ventrally ( Fig. 22C ), arranged in about 6 transverse series per segment dorsally, and about 9 ventrally; posterior chaetigers with 4 transverse series per segment.

Anterior end dissected in paratypes. Cephalic hood short, margin smooth. Prostomium low dark cone, eyes not seen. Caruncle dark, wide basally, reaching branchial plate margin, median and lateral ridges darker than surrounding areas. Palps dark, massive; palp keels rounded, low, dark. Dorsal and lateral lips reduced, invaginated; ventral lip pale, well developed.

Branchiae cirriform, sessile on flat branchial plate, arranged in concentric rows, separated in two lateral groups, each with about 60 filaments ( Fig. 22E ). Branchiae about as long as palps. Nephridial lobes not seen.

Cephalic cage broken in all specimens, relative chaetal length unknown. Chaetigers 1–3 with larger notochaetal lobes, probably involved in cephalic cage, chaetal bases arranged in short U-shaped series. Chaetiger 1 with 9 notochaetal and 5 neurochaetal bases, chaetiger 2 with 5 notochaetal bases.

Anterior dorsal margin of chaetiger 1 projecting forward, papillated. Chaetigers 1–3 of similar length. Chaetal transition from cephalic cage to body chaetae abrupt; aristate neurospines present from chaetiger 2. Gonopodial lobes dark brown, digitate, present in chaetiger 5 ( Fig. 22C ).

Parapodia well developed, lateral; median neuropodia ventrolateral. Notopodia low, rounded lobes with 3 infrachaetal, globose papillae. Neuropodia larger, rounded projected lobes, with 10–12 marginal papillae, 5–6 basal. Notopodia and neuropodia distant to each other.

All notochaetae multiarticulate capillaries (most broken in holotype), articles short basally and medially, subdistally medium-sized, long articles towards chaetal tips ( Fig. 22F ). Notochaetal bases of median chaetigers arranged in short transverse series, each with 3–4 chaetal bases (5 chaetae per bundle in better preserved specimens); about one-third as long as body width in better-preserved anterior fragments. Neurochaetae multiarticulate capillaries in chaetiger 1; aristate neurospines from chaetiger 2 (mostly broken), arranged in transverse series to end of body, 4–5 per bundle. Neurospines with very thin anchylose articles basally and medially, distally paler, almost hyaline, anchylose articles poorly defined, aristate ( Fig. 22G, H ).

Posterior end tapered, blunt ( Fig. 22D ); pygidium with anus terminal, anal cirri absent.

Variation. Complete specimens 12.5–58 mm long, 4.2–9.0 mm wide, cephalic cage 2–4 mm long, 19–26 chaetigers.

Parasites. Two specimens (USNM 1422387, Sta. 3001; 1422388, Sta. 3003) have one monstrilloid copepod parasite attached to each. These are egg-carrying females attached to a palp, which is atrophied and shorter and thinner than the other palp. In normal, non-parasited conditions, palps are thick and of similar length ( Fig. 23A ), but when the parasite is present the palp appears severely atrophied such that it cannot be seen when the head is partly exposed ( Fig. 23B ), but egg masses are easily noticed ( Fig. 23C ). These parasitic females resemble Bradophila Levinsen, 1878 which only includes one species, B. pygmaea Levinsen, 1878 , which has previously been found in Bradabyssa villosa ( Rathke, 1843) n. comb. These specimens differ because the genital somite is longer than wide ( Fig. 23D, E ), whereas in B. pygmaea it is wider than long.

Remarks. In his revision of boreal and arctic flabelligerids, Haase (1915:203) recognized several regional forms for Brada villosa ( Rathke, 1843) and some intermediates among them. Thus, he included Trophonia arctica Hansen, 1880 in the synonymy. McIntosh (1915:104) reached a similar conclusion but with a different approach, he provided some details about the more northern T. arctica , which might indicate that the synonymy should be rejected. Thus, McIntosh stated: “He (Hansen), however, describes the dorsal surface as uniformly granulated, and the papillae on the ventral surface fewer and smaller. On the whole, Hansen form is smoother.” And that: “There are apparently two varieties of Brada villosa , viz. the shorter northern form and the more elongated form (…) Both have the dense coating of sand-grains which, with the papillae, make the dorsum remarkable rugose, yet there are considerable differences in the shorter northern forms from Finmark ( Norway), some of which are less covered with sand.” And regarding the number of chaetigers, he stated a few lines below that “The number of segments in the shorter northern form is about twenty-three, whereas the specimen from the Knight Errant has forty five.” Some of his illustrations further highlight the differences in the development of the body papillae, because they are thin with a very long tip in the southern form whereas they are short and thicker in the northern form (cf. Pl. 96, Fig. 6a vs 6b, c). These differences could promote the reinstatement of T. arctica as a valid species.

However, Støp-Bowitz (1948a:33) did not include T. arctica in the synonymy of B. villosa , but under B. rugosa ( Hansen, 1880, see above). He noticed that the holotypes for both, B. arctica and B. rugosa , were kept together and were so similar that he regarded these species as synonyms, keeping the latter name probably because it had onepage priority and because its name was more indicative of the specimens appearance. I have studied these same specimens and concur with Støp-Bowitz’s conclusion (see above). Thus, in B. rugosa the dorsal tubercles are 2–3 times wider than long, whereas in B. grangieri n. sp. they are slightly wider than long.

Furthermore, for B. villosa Støp-Bowitz (1948:35–36) stated that: “Les papilles dorsales sont fusiformes, allongées, nues a l´extrémité, incrustées de sable au milieu, les ventrales plus petites, presque cylindriques. Autour des soies de longues papilles fusiformes.” This translates as: The dorsal papillae are fusiform, elongate, with tips naked, sand-incrusted medially, the ventral ones smaller, nearly cylindrical. Around the chaetae there are long fusiform papillae. Consequently, since B. grangieri n. sp. corresponds to the southern, shorter form, it cannot be related to B. villosa .

On the other hand, Bradabyssa grangieri n. sp. closely resembles B. annenkovae ( Buzhinskaja, 2001) n. comb. by sharing dorsal tubercles of similar size and bodies with fewer chaetigers (19–26). They differ because in B. grangieri gonopodial lobes are dark and neuropodia have 6–8 basal papillae, whereas in B. annenkovae , gonopodial lobes are pale and neuropodia have 4–5 basal papillae.

Etymology. The specific name is derived after E.H. Grangier, member of the Canadian Arctic Biological Station, in recognition of his marine biological collecting expeditions in 1953–1962, including many benthic samples, and whose materials have been partly used in describing this species.

Distribution. Arctic Ocean, from Canada to Russia, in shallow water muddy bottoms.

Figures

FIGURE 2. Brada granosa Stimpson, 1853. A. Neotype (USNM 1422407), lateral view, anterior end to the right (inset: small paratype, lower right in Fig. 3 A). B. Same, anterior end, ventral view (arrows point to gonopodial lobes). C. Non-type specimen (USNM 22851), head dissected, branchiae and palps removed (Br: branchial scar, PS: palp scar). Scale bars: A: 1.7 mm, B: 1.3 mm, C: 0.4 mm.

FIGURE 6. Brada inhabilis (Rathke, 1843), smaller, non-type specimen (ZMUB 34537). A. Right lateral view. B. Anterior end, lateral view (arrow points to gonopodial papilla). C. Head, frontal view (palps and branchiae removed; Br: branchial scar, PS: palp scar). D. Median parapodium (greenish after methyl-green staining). E. Anterior parapodium notochaetae (inset: enlargement of notochaeta). F. Posterior parapodium, two neurochaetae (insets: neurochaetal tips). Scale bars: A: 2.1 mm, B: 1.3 mm, C: 0.4 mm, D: 0.3 mm, E: 75 µm, F: 120 µm.

FIGURE 12. Bradabyssa alaskensis n. sp. A. Holotype (LACM 2598), right lateral view, tunic slightly eroded. B. Same, anterior end, lateral view (palp and branchiae slightly exposed). C. Paratype (LACM 2599), head, frontal view, palps and branchiae removed (Br: branchial scars, PS: palp scar). D. Holotype (LACM 2598), anterior end, ventral view (arrows point to everted gonopodial lobes). E. Same, close-up of left gonopodial lobe. F. Same, chaetiger 10, right parapodium, frontal view. G. Paratype (LACM 2599), chaetiger 5, right parapodium, notochaetae (insets: medial and distal regions). H. Same, neurochaetae. I. Same, chaetiger 23, right parapodium, neurochaetae. Scale bars: A: 2.5 mm, B: 0.9 mm, C: 0.6 mm, D: 1.2 mm, E: 0.3 mm, F: 0.5 mm, G: 50 µm, H: 100 µm, I: 90 µm.

FIGURE 22. Bradabyssa grangieri n. sp. A. Holotype (USNM 1422382), oblique dorsolateral view, most tunic removed. B. Anterior end, oblique dorsal view. C. Anterior end, ventral view (arrows point to gonopodial lobes). D. Posterior end, oblique dorsal view. E. Paratype (USNM 1422383), head, frontal view, palps and branchiae removed (Br: branchial scars, PS: palp scar). F. Same, chaetiger 10, right parapodium, basal, medial and distal notochaetal regions. G. Same, aristate neurospines, one with a subdistal constriction. H. Non-type specimen (USNM 1422385), chaetiger 10, right parapodium, typical neurospine tips. Scale bars: A: 5.3 mm, B: 1.1 mm, C: 1 mm, D: 1.2 mm, E: 0.9 mm, F: 60 µm, G, H: 120 µm.

FIGURE 23. Bradabyssa grangieri n. sp. and its parasite (USNM 1422388). A. Non-parasitised specimen, anterior end, ventral view, many branchiae missing, palps exposed. B. Parasitised specimen, anterior end, ventral view. C. Same, close-up showing complete egg mass (EM) and healthy palp (Pa). D. Parasite removed from atrophied palp. E. Same, close up showing genital somite (GS), posterior darkened region and egg-masses peduncles. Scale bars: A: 0.4 mm, B: 0.9 mm, C: 0.3 mm, D: 0.7 mm, E: 0.3 mm.