Leptalpheus denticulatus Anker & Marin, 2009

Scioli, Justin A., Robles, Rafael & Felder, Darryl L., 2024, New species and records of the symbiotic shrimp genus Leptalpheus Williams, 1965, with notes on Fenneralpheus Felder & Manning, 1986, and preliminary molecular analysis of phylogenetic relationships (Crustacea: Decapoda: Alpheidae), Zootaxa 5466 (1), pp. 1-72 : 45-46

Leptalpheus denticulatus Anker & Marin, 2009 sensu lato

Leptalpheus denticulatus Anker & Marin, 2009: 92 , figs. 1–6, 7a, b, 8.— Anker, 2010: 38 , fig. 10.—Anker et al., 2015: 320, fig. 14.

Leptalpheus cf. pacificus B.— Anker et al., 2006b: table 1.

Leptalpheus cf. pacificus C.— Anker et al., 2006b: table 1.

Material examined. French Polynesia: 1 ovigerous female (cl 8.9 mm), UF 16463 , Society Islands, Moorea, lagoon near Nihimaru River estuary, near-shore sand flat, 0.5–1 m, coll. A. Anker, 17.11.2008; 1 female (cl 6.6 mm), UF 16527 , Society Islands, Moorea, between Papetoai and hotel, sandflat mounds, rubble and under coral, 0–1 m, coll. A.Anker, 23.11.2008; 1 female (cl 2.7 mm), UF 16525 , same locality as previous, coll. A. Anker, 23.11.2008; 1 male (cl 5.6 mm), UF 16526 , same locality as previous, coll. A. Anker, 23.11.2008; 1 female (cl 4.3 mm), UF UF 16528 , same locality as previous, coll. A. Anker, 23.11.2008; 1 ovigerous female (cl 5.4 mm), UF 16532 , same locality as previous, coll. A. Anker, 23.11.2008; 1 female (cl 5.6 mm), UF 23315 , Society Islands , Moorea, Pihaena, 0.3–1 m, coll. A. Anker, 21.10.2009; 1 female (cl 3.7 mm), UF 23542 , same locality as previous, coll. A. Anker, 21.10.2009 . Mariana Islands: 1 female (cl 6.3 mm), UF 28129 , Guam, south coast, near Aga Point, adjacent to mangrove flats, sand flat, seagrass, 0–1 m, coll. A. Anker, 15.06.2010; 1 male (cl 5.2), UF 28148 , Guam, near Fish Eye Marine Park, seagrass bed and sand flat with rubble, from burrow among seagrass, 0.2–0.5 m, 14.06.2010 . Fiji: 1 male (cl 6.7 mm), LACM CR 2005 - 007.1 (genetic tissue deposited as ULLZ 11842 ) , Viti Levu, Yaqara Bay , 2 km north of Yaqara Pastoral Community, Nasilau Point, sand beach, 0.5–1.0 m, coll. A. Anker & A. Bunouf, 27.01.2005 .

Description. See Anker & Marin (2009).

Color in life. Semitransparent with red chromatophores throughout body; chromatophores densest on antennal and antennular peduncles, uropods, telson, dorsal surface of carapace, and anterior margins of abdominal somites where they are organized into transverse bands; walking legs semitransparent, without chromatophores; major chela hyaline-white; ovaries and eggs yellow-orange (see Anker & Marin 2009: fig. 8; Anker 2010: fig. 10; Anker et al. 2015: fig. 14).

Type locality. Nhatrang Bay , Vietnam .

Distribution. Throughout the central and eastern Indo-Pacific region: Vietnam ( Anker & Marin 2009), the Philippines ( Anker & Marin 2009), Indonesia (Anker et al. 2015), Fiji ( Anker & Marin 2009; present study), French Polynesia ( Anker 2010; present study), and the Mariana Islands (present study).

Ecology. Obligate burrow cohabitant of callichirid ghost shrimps in the genera Glypturus and Neocallichirus : associated with Glypturus armatus (A. Milne-Edwards, 1870) in Vietnam and Indonesia ( Anker & Marin 2009; Anker et al. 2015) and Neocallichirus calmani ( Nobili, 1904) in the Philippines ( Anker & Marin 2009).

Remarks. The genetic analysis by Chow et al. (2021) included two specimens of L. denticulatus , one from New Caledonia and one from Indonesia, and found sequence data from these two specimens to be highly divergent. As discussed above, our phylogenetic analyses strongly supported the hypothesis of L. denticulatus as presently defined to be a species complex containing two species. Sequences published herein from French Polynesian material matched the New Caledonian specimen ( L. denticulatus A) and sequences from the Fijian specimen matched the sequences from the Indonesian specimen ( L. denticulatus B). Preliminary morphological comparisons have yielded no distinguishing morphological characters between these two putative species. It is difficult to speculate which, if any, of these two lineages represent L. denticulatus sensu stricto, which was described from Vietnam. We suggest that a detailed morphometric analysis of all extant material of L. denticulatus sensu lato as well as sequence data from specimens throughout its range, ideally including material from the type locality, will be necessary to properly revise this species complex.