Bradabyssa levensteinae, 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 : 50-52

Bradabyssa levensteinae n. sp.

Figure 25

Brada irenaia .— Levenstein 1961a: 159 –160, Fig. 6 , 1966:46 (non Chamberlin, 1919).

Type material. Northeastern Pacific Ocean. Nine syntypes ( CAS 128946 , 5 spec. and CAS-133021, 4 spec.), variously damaged, off Oregon, Sta. 558 (48°36.5' N, 127°0.8' W), 2189 m, 11 Sep. 1971, A. Carey, coll. (21–40 mm long, 3–4 mm wide, cephalic cage 2.5–4.0 mm long, 31–35 chaetigers).

Additional material. Northeastern Pacific Ocean. Anterior fragment ( USNM 1422368 ), off Santa Cruz Island, Calif. , DOWB Deep Submersible Dive 1-1935 (33°56' N, 119°38.7' W), 9 Mar. 1970, C.E. Roper, coll. (gonopodial lobes dark, lobate, in chaetiger 5; 5–6 series of dorsal papillae). Anterior fragment ( USNM 1422369 ), R.V. Albatross, Sta. 3073 (47°28' N, 125°15' W), 873 m , 28 Jun. 1889 (gonopodial lobes white, rounded, in chaetiger 5; 4–5 series of dorsal papillae). One specimen ( USNM 1422370 ), R.V. Commando, AEC Project SW Mouth Columbia River, Unnumb. Sta. (45°45' N, 125°09' W), shrimp trawl, 1647 m , 29 May 1964, M.S. Alton, coll. (32 mm long, 4.5 mm wide, cephalic cage 4 mm long, 34 chaetigers; gonopodial lobes in chaetiger 5, and another one on right side of chaetiger 4; 5–6 series of dorsal papillae). Northwestern Pacific Ocean. Five specimens (SIORAS V-603), Bering Sea , R.V. Vitjaz, Sta. 603 (59°30' N, 168°00' E), 3034– 2622 m , 16 Sep. 1950, R. Levenstein , id. (two complete 17.5–25.0 mm long, 2.2–4.0 mm wide, cephalic cage 1.8–3.0 mm long, 33–37 chaetigers, gonopodial lobe in chaetiger 5). Two specimens (SIORAS V-1549), Bering Sea, R.V. Vitjaz, Sta. 1549 (60°16' N, 180°16' E), 1710 m, grab (complete, broken in two portions, 12+ 16 mm long, 3.5 mm wide, cephalic cage 2.5 mm long, 13+26 chaetigers, gonopodial papillae in chaetiger 5). Ten specimens (SIORAS V-956), Bering Sea, R.V. Vitjaz, Sta. 956 (coordinates not available) (4 complete: 28–37 mm long, 4–5 mm wide, cephalic cage (damaged) 1.5–2.0 mm long, 42–45 chaetigers, gonopodial papillae in chaetiger 5).

Description. Best syntype (CAS 133021) complete ( Fig. 25A ); body stiff, pale, cylindrical medially, swollen in both ends but anterior half markedly wider than rest of body, anterior end funnel shaped with head partially exposed; 40 mm long, 3 mm wide, cephalic cage 3 mm long, 35 chaetigers. Tunic papillated; one specimen with cuticle detached. Papillae and integument variously covered by fine sand grains, each forming sand tubercles. Tubercles of two different sizes and shapes; smaller ones digitate, larger ones globose, mucronate, about 1/3 as large as neuropodial lobes, all arranged in 6–8 alternating series in median chaetigers.

Anterior end exposed in one specimen (CAS 128946). Cephalic tube short, margin smooth. Prostomium low rounded lobe, eyes colorless. Palps long, thick, with a longitudinal furrow, longer than branchiae; palp keels low, rounded. Caruncle separating branchiae into two lateral groups, with median smooth keel and two lateral ciliated ridges, keel larger, swollen ( Fig. 25B ). Dorsal and lateral lips fused, ventral lip reduced.

Branchiae cirriform, sessile on branchial plate, separated into two lateral groups, filaments arranged in several rows, about 85 filaments per group. Nephridial lobes not seen.

Cephalic cage present, chaetae as long as 1/13 body length or as long as body width. Only chaetiger 1 involved in cephalic cage; chaetae arranged in short lateral series, each with 5 chaetae per side.

Anterior margin of first chaetiger rounded, papillae short, probably eroded (one specimen with long papillae). Chaetigers 1–3 progressively longer. Chaetal transition from cephalic cage to body chaetae abrupt; aristate neurospines present from chaetiger 2. Gonopodial lobes in chaetiger 5 ( Fig. 25C ), short, rounded, pale.

Parapodia well developed, lateral ( Fig. 25D ). Median neuropodia ventrolateral. Notopodia and neuropodia close to each other. Notopodia with chaetal lobe rounded, with 1–2 inferior long papillae, about 1/3 as long as notochaetae; neuropodia with larger rounded lobe, with 4–5 inferior long papillae; notopodial lobes rounded, short.

Median notochaetae arranged in short transverse series, all notochaetae multiarticulate capillaries with articles medium-sized basally, progressively longer ( Fig. 25E ), 5–6 chaetae per bundle, as long as 1/3 body width. Neurochaetae multiarticulate capillaries in chaetiger 1; posterior chaetigers with aristate neurospines, arranged in È-shaped patterns, 5–9 per bundle ( Fig. 25F ). Each neurospine with short rings basally, become slightly shorter medially, distally hyaline with long mucro.

Posterior region slightly swollen ( Fig. 25G ), pygidium with anus terminal, anal cirri absent.

Variation. Complete syntypes 21–40 mm long, 3–4 mm wide, cephalic cage 2.5–4.0 mm long, 31–35 chaetigers; other specimens 17.5–37 mm long, 2.2–5.0 mm wide, cephalic cage 1.8–3.0 mm long, 33–45 chaetigers.

Remarks. These Bradabyssa levensteinae n. sp. specimens were questionably assigned to B. irenaia ( Chamberlin, 1919) n. comb., or B. ochotensis ( Annenkova-Chlopina, 1922) n. comb. by myself during this study. However, they differ in important aspects from both these species: the B. levensteinae specimens possess a marked body constriction from the median segments that continues to the posterior end, a feature that is absent from B. irenaia and B. ochotensis . Levenstein (1961a, 1966) assigned her material to B. irenaia due to having similar chaetiger numbers, but they are different.

However, B. levensteinae n. sp. resembles B. papillata (Hartman, 1967) n. comb. by having long bodies with tubercles of different size but the main differences lie in the body shape, and on the relative pigmentation of neurochaetae; in B. levensteinae the body is wider along the anterior half, and its neurochaetae have transparent tips, whereas in B. papillata the body is wider along its median region, and its neurochaetae have honey-color tips.

Etymology. This species is named after Dr. Raisa Y. Levenstein in recognition of her many publications on polychaete taxonomy and ecology, and her recording of this species from the Bering Sea.

Distribution. Bering Sea to California, in sediments, 873–2189 m water depth.

Figures

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 25. Bradabyssa levensteinae n. sp. A. Syntype (CAS 133021), right lateral view. B. Syntype (CAS 128946), head exposed, branchiae and palps removed (Br: branchial scars, LL: lateral lip, Pr: Prostomium, PS: palp scar). C. Syntype (CAS 133021), anterior end, left lateral view (arrow points to gonopodial lobe). D. Syntype (CAS 128946), chaetiger 15, right parapodium, anterior view. E. Same, notochaetal and notopodial papillae. F. Same, neurochaetae. G. Syntype (133021), posterior region, oblique dorsal view. Scale bars: A: 2 mm, B, G: 0.5 mm, C: 0.6 mm, D: 0.3 mm, E: 70 µm, F: 50 µm.