Fauveliopsis scabra Hartman & Fauchald, 1971, restricted

Figures 21, 22

Brada glabra: Hartman 1965: 173–174 (non Hartman in Hartman & Barnard, 1960).

Fauveliopsis glabra: Hartman & Fauchald 1971: 116–117 (non Hartman in Hartman & Barnard, 1960).

Fauveliopsis scabra Hartman & Fauchald, 1971: 117–118, Pl. 17, Fig. a, b; Hartmann-Schröder 1975: 70–71, Figs. 39, 40 (partim).

TL: Off Bermuda, 4749 m. D: North Atlantic deep basins reaching equatorial regions, in 530–5023 m depth.

Type material: Northwestern Atlantic, off Bermuda. Holotype (LACM 900), and about 400 paratypes (92 complete, LACM 901), R/V Chain, Sta. DR 84 (36°24.4’ N, 67°56’ W), 4749 m, anchor dredge, 4 Jul. 1964, H. Sanders, coll. (holotype 8.3 mm long, 0.7 mm wide, 29 chaetigers; GP or oocytes not seen; complete smaller para- types mostly contracted, body 1.1–2.7 mm long, 0.1–0.5 mm wide, 16–20 chaetigers, posterior chaetigers mostly with one acicular and one capillary per rami; GP or oocytes not seen; complete medium-sized paratypes mostly con- tracted, body 3.9–5.9 mm long, 0.6–0.8 mm wide, 16–20 chaetigers, posterior chaetigers mostly with one acicular and one capillary per rami; GP present in chaetiger 9 in specimens with 23 chaetigers, oocytes not seen; complete larger paratypes slightly macerated, body 7.8–10.1 mm long, 0.5–0.9 mm wide, 26–28 chaetigers; GP single, on the right posterior margin of chaetiger 9; oocytes in one specimen, in posterior 11 chaetigers, 100 µm in diameter).

Additional material. Northwestern Atlantic, off Bermuda. 23 specimens (LACM 7497), 14 complete, R/ V Atlantis, Sta. A 70 (36°23’ N, 67°58’ W), 4680 m, 23 Aug. 1964, H. Sanders, coll. (complete mostly relaxed; body 3.2–8.1 mm long, 0.3–0.8 mm wide, 20–27 chaetigers; GP in chaetiger 9 in specimens with 27 chaetigers, oocytes in chaetigers 11–12, each about 100 µm) . One specimen (LACM 7500), without posterior region, flaccid, R/ V Chain, Sta. 100 (33°56.8’ N, 65°47.0’ W), 4892– 4743 m, 2 May 1965, H. Sanders, coll. (9 mm long, 1 mm wide, 22chaetigers; GP or oocytes not seen) . 12 specimens (LACM 0000), damaged, three complete, with tube remains, R/ V Chain, Sta. 105 (39°56.6’ N, 71°03.6’ W), 530 m, 5 May 1965, H. Sanders, coll. (complete specimens 5.6–10.3 mm long, 0.7–1.1 mm wide, 21–27 chaetigers; GP in chaetiger 9; oocytes not seen) .

Diagnosis. Fauveliopsis with 26–29 chaetigers (Fig. 21A, D). Integument rugose, anterior chaetigers with 5–8 larger dorsal papillae. Anterior and median parapodia with 1–2 aciculars and 1–2 capillaries per rami, and in posterior chaetigers with 1–3 aciculars and 1–3 capillaries (Fig. 21B, E, F). Chaetal formula: 1A1c/1c1A (ant.), 1–2A1c/1c1–2A (med.), 1–2A1–3c/1–3c1A (post.). GP on the right posterior margin of chaetiger 9 (Fig. 22E, inset). In fibrous tubes.

Remarks. Fauveliopsis scabra resembles F. olgae because they have rugose integument, and three or more chaetae per rami along median and posterior regions. As indicated in the key above, their main differences are the chaetiger where genital papillae (GP) ocurr, and the number of chaetae in posterior chaetigers. In F. scabra GP are in chaetiger 8, and there are up to three aciculars and up to three capillaries per bundle in posterior chaetigers, whereas in F. olgae . GP are present in chaetiger 10 (in a non-type specimen), and posterior chaetigers have 3–4 capillaries and the same number of aciculars per bundle.

The original illustration was based upon the holotype, a very relaxed or distorted specimen probably preserved outside of its mollusk shell shelter, because the posterior region is markedly wider than the rest of body (Fig. 21A, C); it is well preserved but the multiple rings shown in the original figures cannot be appreciated as such, but rather as slightly darker rings along anterior chaetigers (Fig. 21B). The paratypes have bodies progressively wider posteriorly, with 16–28 chaetigers (Fig. 21D). Genital papilla is visible towards the posterior margin of chaetiger 8 (Fig. 21E). Posterior end as a blunt cone with long marginal papillae (Fig. 21F), not modified into an anal plate like in the holotype; the parapodia have mostly one acicular and one capillary per rami, and rarely two aciculars can be seen in first or in a few posterior neuropodia (Fig. 21F). Consequently, the species is being restricted to this body pattern.

Other specimens remaining within gastropod shells were examined with SEM (Fig. 22A); their body shape reflects the inner available space of the shells. The prostomium is smooth (Fig. 22B, C) whereas the mouth is surrounded by a ciliated field truncate above, and marginally continued into a thick ciliated belt surrounding the prostomium. Aciculars are finely pubescent along its outer surface (Fig. 22B, inset), whereas the capillary is basally smooth. The posterior end has transverse discontinuous series of low papillae (Fig. 22D); the pygidium has abundant ventral papillae, larger than dorsal ones, with anus transverse, without anal cirri.

The earlier records of F. glabra for the Northwestern Atlantic can be explained because there is another species in the same samples, being quite abundant (Sta. A72, 118; Chain 35, 76, 103), and with 4–6 neurochaetae in posterior chaetigers. However, unlike true F. glabra, whose adult specimens have about 30 chaetigers, these specimens have 15–24 chaetigers and despite their fragmentary condition, at least one mature male was found. As such, they resemble F. adriatica (and F. cf adriatica Katzmann & Laubier, 1974), because both were found in gastropod shells and have many neurochaetae in posterior chaetigers, although the NW Atlantic specimens have less chaetigers. Because these two Mediterranean species were briefly described and their type specimens were not available, describing these specimens as a distinct species must be postponed.