Lamelleulepethus biminiensis Pettibone 1986

Lamelleulepethus biminiensis

Grubeulepis sp. A.—Uebelacker, 1984:24–7, Figs. 24–3, 4a–m.

MATERIAL EXAMINED.—North Atlantic: Between South and East Bimini, sand and Thalassia, M.L. Jones, 20 Aug 1962, holotype (USNM 67470).

Off Georgia: 31°01′N, 80°17′W, 40 m, R/V Pierce sta 5F, 30 Aug 1977, 2 paratypes (USNM 61751-2).

Gulf of Mexico: SOFLA sta 20E, 5 Apr 1981, 25° 17′N, 82°09′W, 22 m, coarse sand, 1 specimen (USNM 74462). MAFLA sta 2421A, Nov 1977, 29°37′N, 84° 17′W, 19 m, silty fine sand, juvenile (USNM 97612); sta 2424A, Feb 1978, 29° 13′N, 85°00′W, 27 m, medium sand, juvenile (USNM 97613); sta 2856C, Sep 1977, 29°54′N, 87°24′W, 30 m, fine sand, 1 specimen (BVA); sta 2960C, D, Nov, Aug 1977, 25°40′N, 82°20′W, 27 m, fine sand, 1 specimen (USNM 97610), advanced juvenile (USNM 97611).

DESCRIPTION.—Length of holotype from Bimini 16 mm, width with setae 5 mm, segments 35. Length of 2 paratypes from waters off Georgia 18 and 16 mm, width 5 mm, segments 35. Length of 2 adults from Gulf of Mexico 18 and 15 mm, width 6 and 4 mm, segments 36 and 34 (USNM 74462, 97610); 2 advanced juveniles 11 mm long, 3–3.5 mm wide, segments 32–33 (USNM 97611-2); smallest juvenile 6 mm long, 2.5 mm wide, segments 26 (USNM 97612).

Elytra 12 pairs, delicate, transparent, fimbriated, becoming more elongate posteriorly; first pair oval, with 9–11 papillae on anterior border (Figures 11A, 15A); following few elytra reniform, with microtubercles on anterior part and 5–6 lateral digitiform processes, 2–4 jointed (Figures 11B,C, 15B,C); middle and posterior elytra squarish to rectangular, also with microtubercles, with entire lateral processes increasing in number: 7 on 6th and 7th elytra, 10 on 11th, 18–22 on 12th (Figure 11D–F). Advanced juveniles with fewer lateral processes (about 15) on 12th elytra and mostly with terminal buds (Figure 15E). Two pairs of dorsal cirri short, subulate, on posterior sides of notopodia of segments 3 and 6 (Figures 11J, 12A). Branchiae 12–13 pairs, beginning on segment 8 and continuing to segment 27 (holotype) or 28 (paratype), large, inflated, with distal papilla (Figure 12c). Dorsal posterior lamellae conical, beginning on segment 28 (small, holotype) or 29 (paratype) and continuing posteriorly (Figures 13A,B, 14D).

Prostomium withdrawn and attached middorsally to enlarged elytrophores of segment 2, rounded anteriorly, with short conical median antenna attached anteriorly and similar lateral antennae attached ventrally, with thick tapered smooth palps (Figure 11G); 4 pairs of small eyes on posterior half (holotype); nuchal organs lateral to prostomium, usually hidden from view. Tentaculophores of segment 1 directed anteriorly, lateral to prostomium, each with 2 acicula, pair of similar dorsal and ventral tentacular cirri, and 2 bundles of smooth and spinous capillary setae (Figure 11H). Elytrigerous parapodium of segment 2 (Figure 11I) with small rounded notopodium and bundle of spinous capillary notosetae; neuropodium similar to following parapodia; neurosetae non-limbate and limbate capillaries, with middle ones stouter; ventral buccal cirrus longer than following ventral cirri. Notopodia of cirrigerous segment 3 with bundle of long capillary notosetae emerging from posterior rounded lobe and notopodial hooks with tips tapered or slightly hooked, finely spinous along bend; neuropodium with single upper pectinate seta, slender limbate capillaries, some middle ones thicker, and single middle smooth acicular neuroseta; ventral cirrus short, tapered (Figure 11J–L). Acicular neurosetae absent on following parapodia.

Biramous parapodia supported by acicula, notoaciculum with hooked tip, neuroaciculum with distal hammer-shaped plate on anterior side (Figures 12B, 14A). Notopodium short, cylindrical, with bundle of numerous capillary notosetae emerging from posterior rounded lobe and extending far beyond neurosetae; dorsally with stout geniculate notopodial hooks with tips tapered or wide spatulate, spinous along bend and distal part (Figures 12B,C,D; 14A,B). Neuropodium thick, rounded, paddle-shaped, with fan-shaped bundle of neurosetae, upper one pectinate (Figure 12E), 4 upper stout limbate neurosetae abruptly narrowed and bent downward, with long slender tips; lower ones slender capillaries (Figures 12B,C,F, 14A,C). Most middle segments of young 26-segment juvenile with 3–4 middle stout acicular neurosetae, smooth, spinous or irregularly roughened, with tips slightly curved (Figure 15F,G; Uebelacker, 1984, fig. 24-4h). Ventral cirri from segment 7 on small, ovoid, papillate, with small cylindrical tips (Figures 12B,C, 13A,B, 14A,D). Ventral lamellae beginning on segments 7–9 as small projecting ridge, forming large flattened digitiform projections from segments 9–10, and continuing to segments 26–28 (Figures 12B,C, 14A).

Parapodia of posterior lamelligerous segments differing somewhat from more anterior parapodia: notopodial hooks all curved downward, with blunt tips and wider spinous regions (Figures 13A–C, 14D,E; Uebelacker, 1984, fig. 24-4e,f); supraacicular group of stout neurosetae (up to 8) curved downward, with tips blunt or with long whip-like capillary tips (Figures 13A,B,D, 14D,F; Uebelacker, 1984, fig. 24-4i). In posterior parapodia of juveniles, upper group of stout neurosetae denticulate, instead of smooth (Figure 15H,I; Uebelacker, 1984, fig. 24-4j).

Pygidium small, with single long papillate anal cirrus on right side and small lobe on left side. Pharynx not examined.

ETYMOLOGY.—The species is named for the place of collection of the holotype, Bimini Island.


Proeulepethus, new genus

TYPE-SPECIES.—Proeulepethus clarki, new species. Gender: masculine.

DIAGNOSIS.—Body short, segments up to 39. Elytra 12 pairs, on segments 2, 4, 5, 7, alternate segments to 21, 24; elytra with lateral borders entire, not notched or fimbriated. Dorsal cirri on segments 3 and 6. Branchiae 10–11 pairs, on segments 8, 10, alternate segments to 22, 23, 25, (26). Posterior dorsal lamellae beginning on segments 26–27, continuing posteriorly. Posterior upper neurosetae not enlarged and curved downward.

ETYMOLOGY.—From the Latin pro (before) plus the generic epithet Eulepethus, indicating its relationship to the eulepethid polychaetes.

Proeulepethus differs from the other genera of Eulepethidae in having elytra with entire borders, not notched or fimbriated.

COMPOSITION.—Proeulepethus includes P. clarki, new species, and P. challengeriae (McIntosh, 1885), new combination (species doubtful).