Lamprophaea cornuta, 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 : 31-32

Lamprophaea cornuta n. sp.

Figs 14 , 15

urn:lsid:zoobank.org:act:1734A20C-A4D3-4E74-90E5-B0DCFD81D61C

Type material. Western Pacific, French Polynesia. Holotype ( UF 882 ), Society Islands , Moorea, E side of Cook’s Bay, opposite to Gump, fringing reef in bay (17°29’17.88” S, 149°49’09.12” W), coral, 1–3 m, 1 Nov. 2008, V. Ivanenko & J. Moore, coll.

Additional material. Western Pacific, Mariana Islands. One specimen ( UF 51 ), Guam, Urunao Reef (13°30’00.00” N, 144°48’00.00” E), reef flat, under ruble, 1 Jun. 2000, C.P. Meyer & G. Paulay, coll. [24.5 mm long, 3 mm wide] .

Description. Holotype (UF 882) complete, mature female, bent dorsally. Body obconic, blunt anteriorly, tapered posteriorly, most cirri missing; 30 mm long, 4 mm wide (without parapodia); left parapodium of chaetiger 7 removed for observing parapodial features. Body blackish, from chaetiger 6 brownish because of abundant tubular ovaries in coelom ( Fig. 14A ); parapodia pale, midventral depression pale, with blackish margins, along chaetigers 1–5.

Prostomium wider than long, widest posteriorly, with angular corners, posterior prostomial margins expanded as small horns ( Fig. 14B ); anterior margin blackish, pigmentation continued posteriorly from bases of pale lateral antennae. Lateral antennae bent ventrally, longer than prostomium and palps; palpophores three times longer than palpostyles (left one missing). Median antennae blackish, directed posteriorly, short (not reaching prostomial anterior margin), inserted between posterior eyes.

Eyes dark brown, anterior ones emarginate anterolaterally, twice larger and slightly more separated than posterior, round eyes; in lateral view, eyes distinct.

Nuchal organs lobes L-shaped, lateral projections barely expanded subdistally, with black ridge, anterior and posterior surfaces paler, projected beyond lateral prostomial margins; lateral ciliated bands wide, visible dorsally. Tentacular cirri mostly missing, one ventral remaining pale, barely surpassing chaetiger 1. Lateral cushions project- ed laterally along middle and posterior chaetigers, smooth, entire, longitudinal striae visible, unless too expanded by gonads.

Pharynx not exposed, mouth wide open ( Fig. 14C ). Lateral vesicles not seen; anterior margin with regular constrictions but not counted. Middorsal jaw single, hyaline, larger than ventral one, inserted below pharynx margin.

Dorsal cirri homogeneously blackish, or banded, most missing, a few remaining without tips, shorter than body width. Chaetigers 1–4 without notochaetae; notochaetae present along chaetigers 5–16, about 60 per bundle, delicate, arranged in transverse fans along most chaetigers, notochaetae subdistally denticulate, denticles coarse. Notacicular lobes long, tapered, three times longer than wide ( Fig. 14D ); aciculae black, tapered; ventral cirri tapered, surpassing neuracicular blunt lobes. Neurochaetae about 30 per bundle, blades or similar size ( Fig. 14E ), shortest ones missing, bidentate, 5–7 times longer than wide, guards approaching subdistal tooth.

Posterior end tapered. Prepygidial segment with cirri barely pigmented, dorsal cirri about 4 times longer than ventral ones. Anus terminal, anal cirri reaching chaetiger 13.

Oocytes about 100 µm. Spermatids not seen.

Variation. A living juvenile specimen from Guam was dark purple ( Fig. 15A ), darker medially, paler posteriorly. Upon preservation most cirri were missing, and after almost 20 years in ethanol, most of its pigmentation has disappeared ( Fig. 15B ). Remarkably, the prostomial margins as well as the lateral branches of nuchal organs lobes are darker than surrounding areas ( Fig. 15C ), and the emarginate, anterior eyes are twice larger than posterior ones. Regarding parapodial features, the notacicular lobes are tapered, and the neuracicular ones are round but about twice wider than long ( Fig. 15D ). Neurochaetal blades are 3–8 times longer than wide.

Etymology. The specific epithet is made after the Latin adjective cornutus (- a, - um) meaning horned, or provided with horns. The name indicates the posterolateral prostomial squarish projections resembling small horns, and it is in feminine for matching the genus gender ( ICZN 1999, Art. 31.2).

Remarks. Lamprophaea cornuta n. sp. belongs in the group of species having notochaetae from chaetiger 5, and resembles L. pleijeli n. sp. from the Western Indian Ocean by having palpophores three or more times longer than palpostyles, prostomial margins angular, and dorsum blackish. These two species especially differ in the relative size of eyes, and in the length of posterior projections of nuchal organs. In L. cornuta anterior eyes are twice larger than posterior ones, and posterior projections of nuchal organs are 3–4 times longer than wide, whereas in L. pleijeli eyes are of similar size, and posterior projections of nuchal organs are about as long as wide.

Distribution. Western Pacific, from Guam to Moorea, in intertidal to shallow subtidal coralline substrates.

Figures

FIGURE 14. Lamprophaea cornuta n. sp., holotype (UF 882). A. Anterior region, dorsal view (interior irregular pale masses are gonads), B.Anterior end, dorsal view. C.Anterior region, ventral view. D. Chaetiger 7, left parapodium, anterior view, MGS. E. Same, neurochaetae and notochaetal tips (*: enlarged blades in F). F. Upper neurochaetal blade and lower neurochaetal blades (different magnification). Scale bars: A: 1.5 mm, B: 0.6 mm, C: 1.2 mm, D: 0.4 mm, E: 0.3 mm, F: thinner blade 200 µm, wider blade 150 µm.

FIGURE 15. Lamprophaea cornuta n. sp., non-type specimen (UF 51). A. Living specimen, dorsal view. B. Preserved specimen, dorsal view. C. Anterior end, dorsal view. D. Chaetiger 8, right parapodium, anterior view (*: enlarged blades in E). E. Superior (left) and inferior (right) neurochaetal blades. Scale bars: A: 3.8 mm, B: 3.3 mm, C: 0.6 mm, D: 0.2 mm, E (left): 30 µm, E (right): 25 µm (photo A: Gustav Paulay).