Lamprophaea pleijeli, Salazar-Vallejo, 2020

Salazar-Vallejo, Sergio I., 2020, Revision of Leocrates Kinberg, 1866 and Leocratides Ehlers, 1908 (Annelida, Errantia, Hesionidae), Zootaxa 4739 (1), pp. 1-114 : 43-45

Lamprophaea pleijeli n. sp.

Fig. 23

urn:lsid:zoobank.org:act:20AA6D5F-EF54-4FC9-A590-E52645074137

Type material. Western Indian Ocean, La Réunion Island. Holotype ( UF 659 ), Saint-Leu,Sec Jaune(21°09’11.88” S, 55°16’51.96” E), rocky slope, basalt blocks, 6–15 m, H. Bruggemann & N. Hubert, coll.

Description. Holotype (UF 659) complete, mature, bent ventrally, and laterally, distorted by dissection of some posterior parapodia. Body obconic, blunt anteriorly, tapered posteriorly, 22 mm long, 3 mm wide (without parapodia); right parapodia of chaetigers 9–12 removed for molecular analysis; left parapodium of chaetiger 8 removed for observing parapodial features. Body blackish along anterior four chaetigers ( Fig. 23A ) and posterior three ones, middle region brownish; parapodia pale, midventral depression blackish, with abundant transverse oval, whitish points.

Prostomium slightly wider than long, tapered posteriorly, anterior margin blackish, posterior margin brownish ( Fig. 23B ). Lateral antennae with ceratophores distinct, longer than prostomium and palps; palpophores 2–3 times longer than palpostyles. Median antenna long, slightly surpassing anterior prostomial margin, inserted centrally on prostomium, between eyes.

Eyes dark brown, anterior ones emarginate anterolaterally, about as large as and slightly more distant to each other than posterior round eyes, in lateral view eyes distinct.

Nuchal organs lobes L-shaped, lateral projections slightly progressively expanded, with black ridge, anterior and posterior surfaces paler, projected beyond lateral prostomial margins; lateral ciliated bands narrow, barely visible dorsally. Tentacular cirri banded, blackish, pigmentation fading out, longest ones reaching chaetiger 8. Lateral cushions low, variably projected, smooth, entire, longitudinal striae visible.

Pharynx exposed, jaws single, inserted subdistally ( Fig. 23C ). Lateral vesicles not seen. Anterior margin with about 20 regular ridges, slightly darker than surrounding pharynx wall, dorsal ones tapered. Middorsal jaw yellowish, larger than ventral one, inserted below pharynx margin.

Dorsal cirri with tips eroded, complete ones smaller than body width (including parapodia). Chaetigers 1–4 without notochaetae; notochaetae present along chaetigers 5–16, about 50 per bundle, delicate, in fascicles along chaetigers 1–9, thereafter in longitudinal fans, notochaetae subdistally denticulate, denticles coarse. Notacicular lobes long, tapered, three times longer than wide; neuracicular lobes slightly longer than wide, blunt ( Fig. 23D ); aciculae black, tapered; ventral cirri tapered, missing in some chaetigers, surpass neurochaetal lobes. Neurochaetae about 30 per bundle, blades decreasing in size ventrally, bidentate, 4–9 times longer than wide, guards approaching subdistal tooth.

Posterior region tapered, venter blackish ( Fig. 2F ). Prepygidial segment with cirri broken, dorsal one twice wider than ventral one. Anal cirri broken.

Oocytes in ovaries, about 100 µm in diameter; spermatids not seen.

Etymology. The specific name is a modest homage to Dr. Fredrik Pleijel, in recognition of his series of publications dealing with taxonomy and phylogeny of hesionids, which have made things easier for anyone interested in the group (including myself), and to provide thanks for his kind support of my research activities during the last 20 years. The species-group name is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Remarks. Lamprophaea pleijeli n. sp. belongs in the group of species with notochaetae from chaetiger 5, and resembles L. cornuta n. sp., from Moorea, by having a blackish pigmentation, palpophores three or more times longer than wide, and peristomial middorsal tubercle truncate. These two species differ, however, especially in the relative size of eyes, and in ventral pigmentation pattern. In L. pleijeli eyes are of similar size, and its midventral depression is blackish, whereas in L. cornuta anterior eyes are twice larger, and midventral depression is paler.

Distribution. Only known from the Western Indian Ocean, in basalt rocky bottoms in La Réunión Island, in water depths of 6– 15 m.

Figures

FIGURE 2. A. Leocrates claparedii (Costa in Claparède, 1868), non-type specimens (USNM 5131), anterior end, dorsal view, pharynx everted. B. Another specimen, anterior end, dorsal view, pharynx fully everted. C. Same, pharynx and jaws, left lateral view (1: Pharynx ring I, 2: Pharynx ring II, AM: anterior margin, DT: dorsolateral tubercle, LJ: lower jaw, LV: lateral vesicle, Pe: peristomium, TB: tentacular belt, UJ: upper jaw). D. Lamprophaea poupini n. sp., holotype (UF 858), anterior end, right lateral view, after SAS (1–8: tentacular cirri, Ch: chaetiger, LA: lateral antenna, NO: nuchal organ lobe, Pa: palp, TB: tentacular belt). Scale bars: A, C: 0.5 mm, B: 0.7 mm, D: 0.3 mm.

FIGURE 23. Lamprophaea pleijeli n. sp., holotype (UF 659). A. Anterior region, dorsal view, depressed by glass slide fragment. B. Anterior end, dorsal view. C. Pharynx, everted, frontal view, MGS. D. Chaetiger 8, left parapodium, anterior view, MGS. E. Same, chaetae (insets: longer and shorter neurochaetal blades). F. Posterior region, ventral view. Scale bars:A: 1.5 mm, B, C, E: 0.5 mm, D: 0.4 mm, F: 2 mm.