Neocallichirus jousseaumei ( Nobili, 1904 )

Poore, Gary C. B., 2023, New records and one new species of Callichiridae (Crustacea, Axiidea) from the Indo-West Pacific, with keys to species of Corallianassa, Lepidophthalmus and Neocallichirus, Memoirs of Museum Victoria (Mem. Mus. Vic.) 82, pp. 71-95 : 86-87

Neocallichirus jousseaumei ( Nobili, 1904)

Callianassa (Cheramus) jousseaumei Nobili, 1904: 236–237 .

Callianassa (Cheramus) indica De Man, 1905: 605 (type locality, Indonesia, Bay of Kankmaralin , S coast of Kangean).

Neocallichirus indicus . — Sakai, 1999: 99, fig. 23a, b, d, e (lectotype, not fig. 23c). — Sakai, 2005: 178–179.— Sakai, 2011: 458.

Neocallichirus jousseaumei .— Sakai, 1999: 100–101, fig. 22e– g.— Sakai, 2011: 458–459 (synonymy).— Dworschak, 2011b: 2–9 , figs 1–4, 6F–H (lectotype designation, redescription, synonymy).— Dworschak, 2014: 232–233, fig. 10b.— Dworschak, 2018: 25–27 (synonymy).— Poore et al., 2019: 145.— Robles et al., 2020.— Padate et al., 2022: 198 (list).

Material examined. Saudi Arabia. Red Sea, Al Lith , 20.167155° N, 40.223307° E (stn SAFA-039), UF 37166 (female, 7 mm) . Oman. Muscat, UF 5439 (female, 6.5 mm) . Papua New Guinea, Madang lagoon, 05° 11.5' S, 145° 49.5' E (stn PR58), MNHN IU-2013- 7044 (male, 8.9 mm). Riwo , 05° 09' S, 145° 48.2' E, 1–2 m (stn PR235), MNHN IU-2013-7039 * (female, 9.3 mm); MNHN IU-2013- 7122 * (male, 4.3 mm) .

Diagnosis. Antenna peduncle exceeding antennule peduncle by half of article 5. Cornea prominent, hemispherical (sometimes with extracorneal pigment); eyestalk distal lobes tapered, often truncate, with denticulate distal margin. Major cheliped merus lower margin with asymmetrically curved blade, widest and denticulate over proximal half, more prominent in adult; gape with molar-like tooth in male; fixed finger cutting edge smooth, or with low proximal tubercles; dactylus cutting edge with molar-like tooth near midpoint, deep notch, concave blade over distal half, or entire. Uropodal endopod posterior margin almost transverse, angle with anterior margin squarish. Telson clearly tapering from subproximal width to rounded corner between well-defined posterolateral margin and convex-straight posterior margin. Maximum cl. 25.6 mm.

Distribution. Western and Central Indo-Pacific ( Saudi Arabia; Oman; Yemen; Red Sea [type locality: Djibouti, Périm]; Persian Gulf; India; Australia, Cocos (Keeling) Is; Indonesia; Papua New Guinea; Japan, Ryuku Is; Thailand; Philippines).

Remarks. The species has a long and complicated synonymy, but its identity was well established by Dworschak (2011b), who described and illustrated several specimens, including type material from Djibouti. The species is notable for the denticulate lobe on the eyestalk, and the major cheliped merus with an almost evenly convex denticulate blade widest about one-third way along.

Sakai (1999, 2005, 2011) listed N. indicus as a valid species, but Dworschak (2011b, 2018) treated C. (Cheramus) indica De Man, 1905 as a junior synonym of N. jousseaumei . He recorded the species from the Red Sea, Persian Gulf, Indonesia, Philippines, Thailand and Cocos (Keeling) Is ( Australia). He also recorded the species from French Polynesia as junior synonym Callianassa taiaro Ngoc-Ho, 1995, following Sakai’s (1999) synonymy of this species with N. indicus (De Man, 1905) . Padate et al. (2022) added India to the distribution.

Dworschak (2011b) argued that Callianassa natalensis Barnard, 1947 , C. manningi Kazmi and Kazmi, 1992 , and C. variabilis Edmondson, 1944 , also synonymised with N. indicus by Sakai (1999), are valid species.

Neocallichirus taiaro Ngoc-Ho, 1995 has been treated as a synonym of N. indicus or N. jousseaumei ( Sakai, 1999; Dworschak, 2011b) but the shape of the eyestalk, chelipeds, female pleopod 2, uropod and telson fall outside the variability of the latter. None of the specimens of Neocallichirus from French Polynesia seen during this study could be identified as N. taiaro or N. jousseaumei .

Molecular data does not distinguish Papua New Guinea and Philippines representatives ( Robles et al., 2020). The juvenile male (MNHN IU-2013-7122) has swollen eyestalks terminating in a typical truncate lobe but lacks pleopod 1, and has a biramous but simple pleopod 2. The uropodal endopod is narrower than in typical N. jousseaumei . Molecular data suggest it is very close to this species ( Robles et al., 2020), but is too small to characterise.