Leocrates seidae, 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 : 72-73

Leocrates seidae n. sp.

Figure 41

urn:lsid:zoobank.org:act:1FF93A83-5079-436E-8B8A-0636C2B6BA42

Type material. French Polynesia, Moorea. Holotype ( SIO A4237 ), W side of Opunohu Pinnacle (17°29’38.76” S, 149°51’43.20” W), 10 m, 11 Nov. 2010. C. Meyer, coll.

Additional material. Papua New Guinea. One juvenile ( SIO A5947), Rosemarie’s Reef, Kilu-Tamare reefs, Kimbe Bay, Bismarck Sea (05°25’05.4000” S, 150°05’30.6600” E), 10–20 m, coral rubble, 18 Apr. 2008, F. Pleijel, coll. [4.8 mm long, 0.5 mm wide]. Two juveniles ( SIO A5962), Rest Orff Island, Kimbe Bay, Bismarck Sea (05°17’35.5800” S, 150°06’15.4202” E), 3–10 m, dead Acropora with brittle stars, Breviturma (olim Ophiocoma) pica ( Müller & Troschel, 1842), 25 Apr. 2008, F. Pleijel, coll. [3.2–4.8 mm long, 0.4–0.7 mm wide]. Australia. One specimen ( AM W29575), Queensland, Lizard Island, west end of Palfrey Island (14°40’ S, 145°30’ E), 3–9 m, rotenone, Acropora head, 3 Nov. 1975, D. Hoese, coll. [15 mm long, 2 mm wide]. One specimen ( AM W43793), Queensland, Lizard Island, Big Vicki’s reef (14°41’10” S, 145°26’32” E), 9 m, coral rubble, 13 Aug. 2013, M. Capa & M.T. Aguado, coll. [13 mm long, 2 mm wide]. One specimen ( AM W43826), Queensland, Lizard Island, front of reef between Bird and South Islands (14°41’52” S, 145°27’50” E), 12–18 m, coral rubble and brown flat algae, 14 Aug. 2013, J. Zanol, coll. [10.5 mm long, 1.5 mm wide]. Two specimens ( AM 43841b), Queensland, Lizard Island, Vicki’s Reef (14°41’17” S, 145°26’35” E), 9 m, calcareous algae, 13 Aug. 2013, M. Capa & J. Zanol, coll. [12–17 mm long, 2–3 mm wide]. One specimen ( AM W44503), Queensland, Lizard Island, North Point, Mermaid Cove (14°38’46” S, 145°27’13” E), 10 m, dead coral, 20 Aug. 2013, J. Zanol et al., coll. [12.5 mm long, 1 mm wide]. Two specimens ( AM W44504), Queensland, Lizard Island, North Point, Mermaid Cove (14°38’46” S, 145°27’13” E), 8–12 m, coral rubble in sand, 20 Aug. 2013, M. Capa et al., coll. [Complete 11 mm long, 1.5 mm wide].

Description. Holotype (SIO A4237), complete, straight ( Fig. 41A ). Body blunt anteriorly, slightly wider medially, tapered posteriorly, 14 mm long, 1.8 mm wide; right body wall and parapodia of chaetigers 11–15 removed for molecular studies; right parapodium of chaetiger 8 removed for observing parapodial features. Tentacular and dorsal cirri mostly broken. Body pale.

Prostomium slightly longer than wide, slightly wider in anterior eyes region ( Fig. 41B ). Lateral antennae with ceratophores distinct, slightly shorter than prostomium, slightly longer than palps; palpophores slightly longer than palpostyles. Median antenna broken, not reaching anterior prostomial margin, inserted centrally, among eyes.

Eyes dark brown, anterior eyes each 1 / 5 prostomial width, twice larger than posterior ones, slightly emarginate anteriorly, more distant to each other than posterior round eyes.

Nuchal organs lobes C-shaped, completely exposed, pale; lateral ciliated bands narrow, not visible dorsally. Tentacular cirri without tips, longer ones reaching chaetiger 6. Lateral cushions low, entire along anterior chaetigers, bipartite in following ones; longitudinal striae barely visible.

Pharynx not exposed, jaws observed through dissection. Lateral vesicles not seen. Anterior margin smooth. Dorsal and ventral jaws single, hyaline, ventral jaw smaller than dorsal one.

Dorsal cirri as long as body width, including parapodia (one in right chaetiger 6 reaches prostomium). Chaetigers 1–4 without notochaetae; notochaetae present along chaetigers 5–16, about 30 per bundle, delicate, arranged as transverse fans or bundles, notochaetae subdistally denticulate, denticles coarse. Notacicular lobes tapered, twice longer than wide; neuracicular lobes blunt, about as long as wide ( Fig. 41C ); ventral cirri markedly longer than neurochaetal lobes. Neurochaetae about 20 per bundle, blades bidentate, decreasing in size ventrally, 5–11 times longer than wide, guards approaching subdistal tooth ( Fig. 41D ).

Posterior region tapered, bent laterally. Prepygidial segment with dorsal cirri three times longer than ventral ones. Pygidium with anus terminal, anal cirri missing.

Gonads without oocytes; either testis or unmature.

Etymology. This species is being named after Dr. Charlotte A. Seid, Collection Manager of the Benthic Invertebrate Collection, Scripps Institution of Oceanography, University of California, San Diego, as a means of appreciation of her careful work and by supporting my research activities. The species-group name is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Variation. The Papua New Guinea specimens (SIO A5947, A5962) are regarded as juveniles because palpophores and palposytles are of the same length and width, whereas in adults they are usually of different width. These juvenile specimens match the adult one from the French Polynesia.

Remarks. Leocrates seidae n. sp. belongs in the group provided with large brown to black eyes, anterior eyes larger than posterior ones, notacicular lobes without terminal projections. However, L. seidae separates from all other species in the group by having short palpophores (up to twice longer than palpostyles), notacicular lobes twice longer than wide, and neuracicular lobes as long as wide.

Distribution. Papua New Guinea, French Polynesia and Australia, in coralline substrates in 3–20 m depth.

Figures

FIGURE 41. Leocrates seidae n. sp., holotype (SIO A4237). A. Dorsal view, posterior right parapodia previously removed, SAS. B. Anterior end, dorsal view. C. Chaetiger 8, right parapodium, anterior view (inset: notacicular lobe and dorsal cirrophore). D. Same, neurochaetae (notochaetae deleted). Scale bars: A: 1 mm, B: 0.4 mm, C: 0.2 mm, D: 100 µm.