Piromis wehei, Salazar-Vallejo, Sergio I., 2011

Salazar-Vallejo, Sergio I., 2011, Revision of Piromis Kinberg, 1867 and Pycnoderma Grube, 1877 (Polychaeta: Flabelligeridae), Zootaxa 2819, pp. 1-50 : 28-30

Piromis wehei n. sp.

Figure 12

Type material. Northwestern Indian Ocean, Sokotra Archipelago. Holotype (SMF-15408), Sokotra UNOPS Expedition, Gulf of Aden, Sta. 713 (12°09.89ʹ N, 52°22.28ʹ E), 10–20 m, 6 Apr. 2000, T. Wehe coll. Paratype (SMF-15339), MSGR 1993 Expedition, near PTL9, Persian Gulf, 7 Feb. 1993, M. Apel coll.

Additional material. Northeastern Indian Ocean, Bay of Bengal. One specimen (LACM-AHF-2514), International Indian Ocean Expedition, Sta. RH 33, mouth of Godavari estuary, Kakinada Bay, Andhra State, 1.6 km SSE of mouth in canal, brown mud with about 55% clay, 2.3 m, 22 Mar. 1964, H. Sanders, coll., anterior fragment, slightly twisted, many chaetae broken.

Description. Holotype (SMF-15408) complete, regenerating posterior end ( Fig. 12 A); body whitish, chaetose, completely covered by sediment particles, larger dorsally ( Fig. 12 B), slightly smaller ventrally ( Fig. 12 C); anterior region slightly bent over its ventral side; tunic papillated. Papillae arranged in longitudinal rows, two dorsal and four ventral. Holotype 29 mm long, 3 mm wide, cephalic cage 5 mm long, 72 chaetigers (regenerating the last 3–4 chaetigers).

Anterior end observed in paratype ( Fig. 12 D). Cephalic hood short, margin smooth. Prostomium brownish. Caruncle well developed, extending to branchial plate margin, lateral ridges and median keel pale, neighbor areas brownish. Branchiae cirriform, spotted, arising on a tongue-like protuberance, separated in two lateral groups, each with about ten concentric, more or less alternating rows; each group with about 130 filaments. Palps shorter than proximal branchiae, spotted; palp keels rounded, low. Lips pale; dorsal and lateral lips fused; ventral lip reduced. Nephridial lobes not seen.

Cephalic cage chaetae about 1/6 as long as body length, almost twice as long as body width. Anterior chaetigers with long papillae, chaetigers 2–11 with notopodial lobes. Chaetigers 1–3 progressively longer. Chaetal transition from cephalic cage to body chaetae abrupt; multiarticulate bidentate neurohooks start in chaetiger 6. Gonopodial lobes not visible (once the tunic is lifted in paratype, they are small, round, pale, in chaetigers 5–6).

Parapodia well developed, rounded dorsal lobes in anterior chaetigers (2–8). Parapodia lateral, median neuropodia ventrolateral. Noto- and neuropodia with long chaetal lobes and long capitate papillae; both with 1–2 shorter prechaetal and 4–5 longer postchaetal papillae per ramus; noto- and neuropodia distant to each other.

Median notochaetae arranged in a ∪-shaped row, transverse to body axis, six notochaetae per bundle, half as long as body width, slightly thinner than neurochaetae; all notochaetae multiarticulated capillaries ( Fig. 12 E), short articles basally, becoming longer medially, decreasing in size distally, distal article fragile, hooked, unidentate. Neurochaetae multiarticulated capillaries with medium-sized articles in chaetigers 1–3, articles become longer in chaetigers 4–5; from chaetiger 6 all neurochaetae shorter, multiarticulated hooks, arranged in a transverse row in anterior chaetigers ( Fig. 12 F); median and posterior chaetigers with neurohooks arranged in a J-pattern; 8–9 per bundle (10–11 in paratype), less abundant in far posterior chaetigers; each neurohook with short anchylosed articles basally, then very long articles, decreasing towards the tip ( Fig. 12 G). Distal article very long, especially in posterior chaetigers (8–14 times longer than wide). Tip hooked, bidentate, accessory tooth not passing the fang.

Posterior end conical (in regeneration); pygidium with anus dorsoterminal, without anal cirri. Paratype with body wall broken, exposing brownish oocytes, about 125 μm in diameter.

Etymology. This species is named after Dr. Thomas Wehe, in recognition of his publications on polychaetes, especially his compilation on Northeastern Indian Ocean polychaetes, and because he collected the holotype.

Type locality. Sokotra Archipelago, Yemen, in shallow water.

Variation. The paratype is a mature female, most sediment particles eroded, broken in three pieces. Paratype 43 (17+9+17) mm long, 4.5 mm wide, cephalic cage 7.5 mm long, and has 87 (31+15+41) chaetigers; oocytes about 150 µm in diameter.

Remarks. Piromis wehei n. sp. resembles P. brisegnoi n. sp. because both bodies with long, abundant chaetae. They differ because in the former notochaetae are thinner than neurochaetae, while in the latter the notochaetae are very thick, being as thick as neurochaetae, and P. w e h e i has a thick cover of sediment particles, which is not seen in P. brisegnoi . Further, P. w e h e i n. sp. differs from most other described species because most of the sediment particles are adhered on their smallest surface, giving them a very irregular profile.

Distribution. Only known from two localities in the Northwestern Indian Ocean, in shallow water.

Figures

FIGURE 12. Piromis wehei n. sp. A. Holotype (SMF- 15408) ,, complete, lateral view. B. Same, anterior end, dorsal view. C. Paratype, anterior end, ventral view. D. Same, head, frontal view; palps and branchiae removed (BS: branchial scars, LL: lateral lip, PS: palp scar). E. Holotype, notochaetae from chaetiger 19, basal, median and distal sections (insert: tip or notochaeta). F. Same, neurochaetae from chaetiger 10. G. Same, neurochaetae from chaetiger 71. Scale bars: A: 3 mm, B: 1 mm, C: 1.5 mm, D: 0.3 mm, E: 110 µm, F – G: 200 µm.