Leocrates ahlfeldae, 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 : 48-50

Leocrates ahlfeldae n. sp.

Fig. 25

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Type material. Indian Ocean. India. Holotype ( USNM 48942 ), and paratype ( USNM 1548294 ), Mirkae Wada, Ratnagiri (16°59’40” N, 73°18’00” E), Maharashtra, Mumbai (Bombay) Province , intertidal, mixed shore, oyster and bivalve shells, rocks and white sand, 28 Aug. 1969, U.D. Gaidwad, coll. [paratype releasing oocytes through dissections made for parapodia; right parapodia of chaetigers 7 and 8 previously removed, left parapodium of chaetiger 10 dissected (all kept with specimen). Body slightly dehydrated, 23 mm long, 2.5 mm wide, 16 chaetigers; some body appendages damaged. Antennae without tips, palps twisted. Eyes brownish, reniform, anterior ones slightly larger than posterior ones, directed anterolaterally, posterior eyes directed posterolaterally; a small anterolateral dissection previously made for observation of jaws. First dorsal cirri complete, longer than body width including parapodia (reaching chaetiger 5), others broken; notacicular lobes tapered, neuracicular lobes round, truncate, slightly directed upward. Neurochaetal blades 1–8 times longer than wide; oocytes abundant by chaetigers 7 and 8, rare by chaetiger 10, each about 100 µm].

Description. Holotype (USNM 48942) complete, slightly dehydrated medially and posteriorly, bent laterally ( Fig. 25A ). Body with parallel sides, blunt anteriorly, tapered posteriorly, 18 mm long, 2 mm wide, 16 chaetigers; left parapodium of chaetiger 7 dissected (kept in container). Tentacular and anterior dorsal cirri almost complete, others broken partially or missing. Body pale, eyes brown.

Prostomium wider than long, lateral margins curved, wider medially ( Fig. 25B ). Lateral antennae with ceratophores distinct, antennae 1.5 times longer than prostomium, barely longer than palps. Palpophores three times longer than palpostyles. Median antenna missing, inserted between posterior eyes.

Eyes dark brown, reniform, anterior eyes each 1 / 12 prostomial width, twice larger than posterior ones, slightly emarginate anterolaterally, more distant to each other than posterior eyes, posterior eyes emarginate posterolaterally.

Nuchal organs lobes horizontal C-shaped, completely concealed by anterior margin of tentacular belt; lateral ciliated bands narrow, barely visible. Tentacular cirri without tips, longer ones reaching chaetigers 6/7. Lateral cushions low, entire, collapsed by partial dehydration. Longitudinal striae visible along middle and posterior chaetigers.

Pharynx fully exposed, slightly expanded distally. Lateral vesicles present on both sides, collapsed, tapered. Anterior margin with 22 regular constrictions, ventrally smaller, a larger one middorsally, three smaller ones midventrally ( Fig. 25C ). Dorsal and ventral jaws brownish, exposed, tapered, ventral jaw smaller than dorsal one.

Dorsal cirri at least as long as body width (including parapodia). Chaetigers 1–4 without notochaetae; notochaetae present along chaetigers 5–16, about 50 per bundle, delicate, arranged as transverse or oblique fans, notochaetae subdistally denticulate, denticles fine. Notacicular lobes tapered, neuracicular lobes projected, blunt, slightly longer than wide ( Fig. 23 ); aciculae black, tapered; ventral cirri surpassing neurochaetal lobes. Neurochaetae about 30 per bundle, blades decreasing in size ventrally, bidentate, 2–10 times longer than wide, guards approaching subdistal tooth ( Fig. 23E, F ).

Posterior region tapered, almost without cirri. Preanal segment without cirri. Pygidium with anus terminal, anal cirri missing.

Oocytes in ovaries, each about 100–150 µm; sperm masses not seen.

Etymology. This species name is after Kathryn Ahlfeld, collection manager in the National Museum of Natural History, Smithsonian Institution, Washington, because she has been very helpful during my research visits there, and extremely collaborative in dealing with type materials. The species-group name is a noun in the genitive case ( ICZN 1999, Art. 31.1.2).

Remarks. Leocrates ahlfeldae n. sp. belongs in the group of species with small eyes, although anterior eyes twice larger than posterior ones, and with notacicular lobes tapered, together with L chinensis Kinberg, 1866 from Hong Kong, and L. giardi Gravier, 1900 from the Red Sea. However, L. ahlfeldae differs from the two other species by having lateral prostomial margins curved, expanded, and because the lateral pharynx vesicles are tapered, whereas in the two other species prostomial lateral margins are straight, and pharynx vesicles are blunt.

Distribution. The type specimens were collected in Maharashtra, Mumbai ( Bombay) Province, in intertidal environments. Some records of L. claparedii (Costa in Claparède, 1866) for the northern Indian Ocean might correspond to this species but specimens were not available for validation. There are records for the Persian Gulf ( Fauvel 1919: 371), the Arabian Sea ( Aziz 1938: 24, Mohammad 1972: 555), south of Bombay ( Day 1973: 344), the Gulf of Mannar ( Fauvel 1930: 12–13), the Bay of Bengal and Sri Lanka ( Fauvel 1932: 61; Fauvel 1953b: 106-107, Fig. 50 c–g).

Figures

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.

FIGURE 25. Leocrates ahlfeldae n. sp., holotype (USNM 48942).A.Anterior region, dorsal view. B. Anterior end, dorsal view. C. Pharynx, frontal view, MGS. D. Chaetiger 7, left parapodium, anterior view (insets: notacicular and neuracicular lobes). E. Upper neurochaetal blades. F. Lower neurochaetal blades. Scale bars: A: 1.1 mm, B: 0.3 mm, C, D: 0.5 mm, E: 100 μm, F: 150 μm.

FIGURE 50. Paradalhousia oculata (Treadwell, 1906), new combination, reinstated, non-type specimen (AMNH 476). A. Dorsal view. B. Anterior region, dorsal view (*: left dorsolateral tubercle). C. Anterior region, oblique left lateral view (*: left dorsolateral tubercles). Scale bars: A: 1.7 mm, B, C: 0.4 mm (photos: V.M. Conde-Vela).