Pelogenia capitata sp. nov.

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Figs 2Q–R, 19–20

? Pelogenia anoculata – Pettibone 1997: 62 (non Hartman, 1939).

Diagnosis

A species of Pelogenia with short palps reaching segments 3–5; middorsal lobe of segment II absent, surface papillate; neurochaetae from segment II with dentate basal surface; neurochaetae from posterior segment with short thick blades; papillate medial process in posterior elytra with capitate papillae.

Etymology

The specific name of the species is a Latin singular adjective ‘ capitata (-us, -um)’, meaning ‘capitate’. The name indicates the presence of capitate papillae on the elytral surface, and it is feminine for matching the generic gender (ICZN 1999, Art. 31.2).

Material examined

Holotype MEXICO • complete spec.; Quintana Roo, Isla Contoy, in front of CONANP station; 21°28′21.09″ N, 86°47′23.87″ W; 1 Mar. 2001; ECOSUR 291.

Paratype MEXICO • 1 incomplete spec., 47 segments, 0.9 cm long, 0.6 cm to segment 30, 0.2 cm wide; Quintana Roo, Isla Contoy; approximately 21°27′37.06″ N, 86°47′19.34″ W; 12 May 1983; ECOSUR 292 .

Other material

MEXICO • 1 complete spec., 69 segments, 1.8 cm long, 0.8 cm to segment 30, 0.3 cm wide; Quintana Roo, Mahahual Sur; approximately 18°42′44.74″ N, 87°42′32.01″ W; 4 Jun. 1998; depth 40 cm; on Thalassia testudinum; S.I. Salazar-Vallejo and L.F. Carrera-Parra leg.; ECOSUR-P3226 • 1 complete spec., 80 segments, 1.9 cm long, 0.7 cm to segment 30, 0.3 cm wide; Quintana Roo, Mahahual Norte; 18°43′28″ N, 87°42′05″ W 19 Jan. 2001; ECOSUR-P3227 • 1 incomplete spec., 33 segments, 3.5 cm long, 3.2 cm at segment 30, 0.1 cm wide; Quintana Roo, Mahahual; 18 Mar. 2001; Kristian Fauchald leg.; ECOSUR-P3228 • 1 complete spec., 56 segments, 1.4 cm long, 0.8 cm to segment 30, 0.25 cm wide; Quintana Roo, Xcalac; 29 Aug. 2002; ECOSUR-P3229 • 2 specs, 78–86 segments, 1.5–2 cm long, 0.6–0.7 cm to segment 30, 0.4–0.6 cm wide; Quintana Roo, Banco Chinchorro, Cayo Norte; 18°45′46″ N, 87°15′84″ W; Edwin Link Submersible; depth 60 m; Elva Escobar and Luis Soto leg.; ECOSUR-P3230 .

Description (holotype)

BODY. Pale yellow, short, broad (Fig. 19A); 59 segments, 1.7 cm long, 0.8 cm to segment 30, 0.3 cm wide. Middorsal line covered with white foreign particles attached to adhesive papillae (Fig. 19B). Venter covered with long papillae and short globular papillae (Fig. 19C).

PROSTOMIUM. Retracted, oval, wider than long. Two pairs of eyes, anterior eyes larger. Lateral antennae long, ceratophores short, as long as styles, dorsally fused with tentacular segment and partially covered by median antennal ceratophore. Median antennal ceratophore bulbous, slightly longer than prostomium, with a longitudinal ridge; style slender, long, twice as long as ceratophore (Fig. 19D). Middorsal lobe of segment II absent, surface papillate. First segment directed anteriorly; fused with tentacular segment; biramous, chaetae simple verticillate. Dorsal tentacular cirrus longer than neuropodia including chaetae, ventral tentacular cirrus slightly shorter than dorsal tentacular cirrus, but longer than neuropodia; palps short, barely reaching segment three, with inner palpal sheaths (Fig. 19C).

ELYTRA. First right elytron subtriangular without perceptible processes, instead, an expanded rounded lobe on anterior margin, covered with coarse sand and four kinds of papillae (Fig. 20I); elytral surface with pedunculate papillae with puffed tips; elytral margin with pedunculate capitate papillae (Fig. 20L). Second right elytron pear-shaped with one medial process (Fig. 20J); four types of papillae, elytral surface with wide pedunculate papillae with puffed tips, scattered on the elytron; on the margin, short dendritic papillae and pedunculate capitate papillae, some of them bifurcated. Posterior elytron oval with one large medial process (Fig. 20K), elytral surface with pedunculate papillae with puffed tips (Fig. 20M–O).

RIGHT PARAPODIUM FROM SEGMENT II (Fig. 19F). Notopodia rounded, papillate, short, half as long as neuropodia. With up to 30 simple verticillate notochaetae, tip hooked, shortest ones as long as notopodia, longest ones 4 × as long (Fig. 19G). Neuropodia conical, papillate, larger than notopodia. Neurochaetae only falcigers; all blades unidentate, falcate: unit A, one falciger with handles thick, whorled with 17–13 transverse rows of spines, blades long, 15–16 × as long as wide, basally dentate with several rows of denticles randomly distributed (Figs 19H, 20F–H); unit C, five falcigers with handles slender, whorled with 12–14 transverse rows of spines, blades medium-sized, 8× as long as wide (Fig. 19I); unit D, two falcigers with handles slender, whorled with 8–9 transverse rows of spines, blades long, 9× as long as wide (Fig. 19J). Unit B, apparently absent.

RIGHT PARAPODIUM FROM SEGMENT III (Fig. 19K). Dorsal cirrus with cirrophore short, style long, 3× as long as cirrophore (Fig. 19E). Notopodia truncated, smooth (non-papillate) and short, slightly shorter than neuropodia. With up to 30 simple verticillate notochaetae, tips hooked, shortest ones slightly shorter than notopodia, longest ones 3× as long (Fig. 19L). Neuropodia conical, papillate, larger than notopodia. Neurochaetae only falcigers; units A and D with blades unidentate, falcate; units C and subunit 1 with blades bifid, most of the blades with subdistal tooth broken: unit A, four falcigers with handles thick, whorled with 15–17 transverse rows of spines, blades medium-sized, 6× as long as wide (Fig. 19M); unit B, two neurochaetae with handles thick, whorled with 10 transverse rows of spines, blades lost (Fig. 19N); unit C, two falcigers with handles thick, whorled with 6 transverse rows of spines, blades medium-sized, 6–7 × as long as wide (Fig. 19O); subunit 1, one falciger with handles thick with 4 transverse rows of spines, blades medium-sized, 5× as long as wide (Fig. 19P); unit D, four falcigers with handles slender, whorled with 8– 9 transverse rows of spines, blades long, 9– 10 × as long as wide (Fig. 19Q).

RIGHT PARAPODIA FROM SEGMENT 25 (MIDDLE SEGMENT) (Figs 19R, 20A). Notopodia conical, smooth (nonpapillate), short, half as long as neuropodia. With up to 50 simple verticillate notochaetae, tips hooked, shortest ones as long as notopodia, longest ones 2× as long as notopodia (Figs 19S, 20B–C). Neuropodia conical, papillate, larger than notopodia. Neurochaetae only falcigers; all blades unidentate, falcate: unit A, four falcigers with handles thick with subdistal transverse rows of denticles, blades short, 2 × as long as wide (Figs 19T, 20D); unit B, two falcigers with handles thick with barely perceptible subdistal transverse rows of denticles, blades short, less than 2× as long as wide (Figs 19U, 20D); unit C, four falcigers with handles slender with transverse subdistal rows of denticles, blades short, 2× as long as wide (Fig. 19V); unit D, three falcigers with handles slender with subdistal transverse rows of denticles, blades medium-sized, 5–7 × as long as wide (Figs 19W, 20E).

PYGIDIUM. Rounded with two anal cirri (Fig. 20P).

Remarks

Pelogenia capitata sp. nov. resembles P. anoculata Hartman, 1939 from the Pacific coast of Costa Rica, in having neurochaetae with short blades, and elytra with only one process. However, both species show morphological discrepancies. Specimens of P. capitata sp. nov. have neurochaetae with very short

blades, handles with grooves, and posterior elytra with pedunculate capitate papillae on their surface and margins. On the contrary, specimens of P. anoculata have neurochaetae with short blades, handles with transverse rows of spines (Hartman 1939: 142, pl. 22 figs 271–272), and posterior elytra with pedunculate papillae with puffed tips on their surface and margins (Hartman 1939: 142, pl. 22 figs 269– 270). However, P. capitata sp. nov. resembles P. anoculata sensu Pettibone (1997: 62); she redescribed the species by combining the type material from the Pacific Ocean with other from the Caribbean Sea (Turks and Caicos, Venezuela, Panama) and Florida, and her illustrations were based on specimens from the Caribbean coast of Panama (with material previously identified by Fauchald (1977) as P. spinosa Hartman, 1939). It is possible that specimens from the Caribbean Sea, described and illustrated by Pettibone (1997), belong to this novel species.

Distribution

Caribbean Sea. Quintana Roo to Panama.