Figure 1
Fauveliopsis adriatica Katzmann & Laubier, 1974: 531–534, Fig. 2.
Fauveliopsis cf. adriatica: Katzmann & Laubier 1974: 535–537, Fig. 3.
Fauveliopsis glabra: López 2011: 2–4, Figs. 1–2 (non Hartman in Hartman & Barnard, 1960).
TL: Adriatic Sea. D: Only known from the Adriatic Sea in two localities, 54–62 m; probably reaching 400 m. Deeper records might belong to a different species.
Type material: Mediterranean Sea, Adriatic Sea, Holotype (NHMW 13224), S off Prvić Luka (43°42.6’ N, 15°47.7’ E), 54–62 m, no date provided (not seen; specimens 3–4 mm long, 0.7 mm wide, 21–26 chaetigers).
Additional material. Western North Atlantic. One specimen (LACM 7523) from scaphopod, R/V Atlantis, Sta. A72 (38°16’ N, 71°47’ W), epibenthic sled, 2864 m, 24 Aug. 1964, H.L. Sanders, coll. (body wall slightly broken in a posterior chaetiger, 12 mm long, 1 mm wide, 30 chaetigers; GP between chaetigers 11 and 12). 13 specimens (LACM 7525), R/ V Atlantis, Sta. A 87, Jul. 1963, H.L. Sanders, coll. (five straight, others bent, straight ones 1.4–9.0 mm long, 0.2–0.9 mm wide, 17–36 chaetigers; GP seen in largest specimen, on the right side, before chaetiger 11; one mature female with oocytes about 100 µm). Seven specimens (LACM 7527), off Surinam, N off Amazon River mouth, R/ V Chain, Sta. Dr 33 (07°52’ N, 54°31.5’ W to 07°55’ N, 54°35’ W), 520–550 m, anchor dredge, 25 Apr. 1963, H.L. Sanders, coll. (in gastropod and scaphopod shells; two out of shells, 1.3–6.1 mm long, 0.3–0.7 mm wide, 28–29 chaetigers; GP not seen). 27 specimens (LACM 7529), from gastropod shells, twisted, broken, R/ V Chain. Sta. Dr. 76 (39°38.3’ N, 67°57.8’ W), 2862 m, 29 Jun. 1965, H.L. Sanders, coll.
Diagnosis. Fauveliopsis with 17–36 chaetigers. First three chaetigers with two aciculars per ramus. Median parapodia with 1–2 aciculars and 1–2 capillaries per ramus. Posterior chaetigers with aciculars and capillaries; 3–4 notochaetae and 3–8 neurochaetae. Pygidium with spherical papillae. GP in posterior margin of chaetiger 10 in largest specimens (over 6 mm long). In gastropod and scaphopod shells.
Additional observations. Specimens living inside gastropod (Olivella Swainson, 1831, Seguenzia Jeffreys, 1876, vitrinellids) or scaphopod (Cadulus Philippi, 1844) shells (Fig. 1A). They accumulate fine particles inside gastropod shells and apparently promote cementation, or precipitation of some mineral particles over both gastropod or scaphopod shells. Anterior end truncate (Fig. 1C), posterior region blunt; anterior region segments twice wider than long, medial and posterior regions with segments three times wider than long (Fig. 1B). GP small round structure very close to the border of chaetiger 11 (Fig. 1B, inset). Oocytes visible in the posterior region, especially ventrally, each about 100 µm in diameter (Fig. 1D).
Remarks. Fauveliopsis adriatica resembles F. magna by having genital papillae (GP) on the right side, and body surface papillated; they differ in the chaetiger where GP are present, and on the relative number of chaetae along posterior chaetigers. In F. adriatica the GP are present before chaetiger 11, and 3–8 capillaries in posterior chaetigers, whereas F. magna has GP before the chaetal lobe of chaetigers 13 or 14, and only 2–3 capillaries in posterior chaetigers.
Katzmann & Laubier (1974:535–537, Fig. 3) found another specimen living in a gastropod shell, from a nearby locality, and with similar number of neurochaetae in posterior chaetigers, but with more papillose integument and with less chaetae in posterior chaetigers. It must be noted that these specimens were identified as F. cf. adriatica (NHMW 13223), and they probably belong to the same species because they have about the same number of chaetigers, although they were larger (6 mm long, 0.2–0.3 mm wide, 26 chaetigers); from deeper water (400 m), and one of them was a mature female (oocytes 250 µm). Several specimens found in deeper waters in the Northwestern Atlantic, previously identified as F. glabra, are herein regarded, with hesitation, as conspecific with F. adriatica. The main difference between these two species relies on the number of acicular chaetae along anterior chaetigers; in F. adriatica there are only aciculars whereas in F. glabra there are aciculars and capillaries. The type materials were not available but because of their number of chaetigers, they are probably juveniles. The clarification of the affinities between these shallow water species with the deeper water forms requires the study of type material.