Leocrates mooreae, 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 : 63-65

Leocrates mooreae n. sp.

Figs 34 , 35

urn:lsid:zoobank.org:act:430BA70F-6820-4E50-B512-F8ECEC81A074

Type material. Western Pacific. New Caledonia. Holotype ( UF 5619 ) , Province Sud, Noumea, Baie de Citron , south part (22°18’14.40” S, 166°26’02.40” E), fringing reef, 2 m, under rocks, 31 Oct. 2017, G. Paulay & M. Hoban, coll. Paratype ( UF 5021 ) , Province Sud, Baie de Prony, Embouchure Carénage (22°19’22.80” S, 166°50’24.00” E), 0–8 m, mangroves and lagoon reef, 6 Dec. 2016, G. Paulay & L. Moroz, coll. (used for variation, 24 mm long, 2 mm wide) .

Description. Holotype (UF 5619) complete ( Fig. 34A ), bent laterally because of previous left dissection along chaetigers 8–10, exposing tubular gonads; anterolateral dissection made for observing pharynx jaws; left parapodium of chaetiger 11 and right parapodia of chaetigers 8 and 15 removed for observing parapodial features. Body pale, finely maculated with brownish transverse thin spots, larger brownish basal spots along posterior parapodial surfaces, 33 mm long, 3 mm wide, 16 chaetigers.

Prostomium rectangular, longer than wide ( Fig. 34B ). Lateral antennae with ceratophores distinct, as long as prostomium, slightly longer than palps; palpophores 2–3 times longer than palpostyles. Median antennae reaching anterior prostomial margin, inserted between posterior eyes.

Eyes dark brown; anterior eyes each 1 / 5 – 1 / 6 prostomial width, reniform, twice larger than posterior ones, slightly more distant to each other than posterior round eyes; in lateral view anterior and posterior eyes distinct.

Nuchal organs U-shaped, posterior prostomial projections darker than nuchal organs areas. Tentacular cirri faintly annulated, without tips, longest ones surpassing chaetiger 3. Lateral cushions low, barely projected entire, longitudinal striae visible.

Pharynx invaginated; anterior margin with about 22 marginal constrictions; upper jaw single, brownish, blunt; lower jaw not seen, probably damaged by dissection.

Dorsal cirri broken, shorter than body width. Chaetigers 1–4 without notochaetae. Notochaetae present along chaetigers 5–16, about 40 per bundle, subdistally denticulate, denticles fine. Notacicular lobes tapered, digitate, with three ( Fig. 34C ) or two distal projections ( Fig. 34D ). Neurochaetal lobes conical; aciculae black. Neurochaetae about 30 per bundle, blades decreasing in size ventrally, 3–10 times longer than wide; blades bidentate with longer basal spines, guards smooth, approaching subdistal tooth ( Fig. 34E, F ).

Posterior region tapered ( Fig. 34G ). Prepygidial segment with dorsal cirri three times longer than ventral ones. Pygidium tubular, anus terminal, anal cirri without tips, reaching chaetiger 14.

Gonad tubes exposed by dissection, invading parapodial coelom. Oocytes about 100 µm; spermatids not seen.

Variation. Paratype (UF 5021), complete, slightly dehydrated. Body twisted, blunt anteriorly, tapered posteriorly, dorsum paler along first 6 chaetigers, creamy in following ones ( Fig. 35A ); right parapodium of chaetiger 9 removed for observing parapodial features. Tentacular and dorsal cirri complete. Body pale, eyes blackish. Prostomium twice wider than long, slightly wider anteriorly ( Fig. 35B ). Lateral antennae with ceratophores distinct, antennae longer than prostomium, slightly longer than palps; palpophores 2–3 times longer than palpostyles. Median antenna tapered, barely reaching anterior prostomial margin, inserted between posterior eyes. Eyes blackish, anterior ones about 1 / 10 as wide as prostomial width, twice larger than posterior ones, almost round anteriorly, more distant to each other than posterior round eyes. Nuchal organs lobes horizontal C-shaped, concealed by posterior projection of prostomium; lateral ciliated bands narrow, barely visible dorsally. Tentacular cirri almost complete, longest ones reaching chaetiger 8. Lateral cushions low, entire, longitudinal striae not visible (probably after dehydration). Pharynx almost fully exposed ( Fig. 35C ); lateral vesicles not seen; anterior margin with about 30 irregular constrictions. Jaws single, yellowish, upper jaw twice longer than lower one, tapered in lateral view, inserted slightly ahead of lower jaw. Dorsal cirri longer than body width (including parapodia). Chaetigers 1–4 without notochaetae; notochaetae present along chaetigers 5–16, about 20 per bundle, arranged as bundles, subdistally denticulate, denticles fine. Notacicular lobes tapered, with a small, digitate projection along its upper part; neuracicular lobes blunt, conical slightly longer than wide; ventral cirri surpassing neurochaetal lobe ( Fig. 35D ). Neurochaetae about 15 per bundle, blades bidentate, decreasing in size ventrally, 5–30 times longer than wide, guards approaching subdistal tooth ( Fig. 35E ). Posterior region tapered. Preanal segment with dorsal cirri 2–3 times longer than ventral ones. Pygidium with anus terminal, anal cirri reaching chaetiger 13. Oocytes not seen; gonads visible by transparency in posterior region, but not dissected to avoid further damage.

Etymology. The specific name is to honor Dr. Jenna Moore, from the University of Florida, Gainesville, as an appreciation for her many efforts to support my research, and for her help in many important details regarding molecular analyses. The species-group name is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Remarks. Leocrates mooreae n. sp. belongs in the group of species provided with large eyes, anterior ones often twice larger than posterior ones. However, L. mooreae is the only species having notacicular lobes provided with terminal digitate projections, making it unique among all other species in the genus, although the number of projections vary, being onely one in smaller specimens (paratype), and up to three in larger specimens (holotype).

Distribution. New Caledonia, in mixed bottoms with mangroves and coral reefs, in 0–8 m depth.

Figures

FIGURE 34. Leocrates mooreae n. sp., holotype (UF 5619). A. Anterior region, dorsal view. B. Anterior end, dorsal view. C. Chaetiger 8, right parapodium, anterior view, MGS (inset: notacicular lobe). D. Chaetiger 11, left parapodium, anterior view, MGS (inset: notacicular lobe). E. Same, upper and lower neurochaetal blades. F. Same, lower neurochaetal blades. G. Posterior region, dorsal view. Scale bars: A, G: 2 mm, B: 0.6 mm, C: 0.3 mm, D: 0.4 mm, E: 120 μm, F: 100 μm.

FIGURE 35. Leocrates mooreae n. sp., paratype (UF 5021).A. Anterior region, dorsal view, depressed by glass slide. B. Anterior end, dorsal view. C. Anterior end, oblique, right lateral view, MGS. D. Chaetiger 9, right parapodium, anterior view, MGS (inset: notacicular lobe). E. Same, neurochaetal tips (insets: tips of neurochaetal blades). Scale bars: A: 1.5 mm, B: 0.3 mm, C: 0.5 mm, D: 0.2 mm, E: 0.1 mm.