Atydina, Cai, Yixiong, 2010

Cai, Yixiong, 2010, Atydina, a new genus for Caridina atyoides Nobili, 1900, from Indonesia (Crustacea: Decapoda: Atyidae) *, Zootaxa 2372, pp. 75-79 : 75-76

Atydina gen. nov.

Type species: Caridina atyoides Nobili, 1900 ; by monotypy; gender feminine.

Diagnosis. Body robust, pigmented, eyes well developed; rostrum rather abruptly narrowing to apex, strongly compressed laterally, without lateral lobes, median dorsal carina unarmed, ventral keel with 0–2 teeth; anterior margin of carapace armed with antennal spines, pterygostomial margin subrectangular; supraorbital spine absent; ventral margin of second through fifth abdominal pleura without sclerotized spinules; telson with posterolateral angle not reaching beyond setiferous posterior margin; third maxilliped ending in a spine; pereiopods without exopods; first and second pereiopods with chelae not dimorphic, palm well developed; fingers tipped with brushes of long setae, carpus of first pereiopod moderately excavated anteriorly, longer than wide, distinctly shorter than chela; second pereiopod with carpus slightly longer than chela; third pereiopod with a prominent meral spur in large males; branchial formula with 9 pairs of gills, 5 sets of mastigobranchs; epipods present on third maxilliped and first 4 pereiopods; endopod of first pleopod of male subtriangular, with appendix interna distinctly reaching beyond its anterior end; second pleopod of male with appendix masculina inflated, cylindrical, spinose over distal half of appendix interna.

Remarks. Although the type specimens of C. atyoides were not available for the present study, Bouvier (1925: fig. 587) figured the type material in detail. Using one pair of specimens from ZMA, a detailed comparison with Atya -like Indo-Pacific genera was carried out. It clearly demonstrates that C. atyoides is much more closely related to Atyopsis than other genera, especially when one considers the prominent spur on the merus of the third pereiopods of males. At the same time it also shares several characters with Caridina , i.e. the gill formula, the rostrum, the telson, and the first two pereiopods, thus representing an intermediate form between Atyopsis and Caridina . The new genus so far has only one species, Atydina atyoides , from Pulau Sipura, near Sumatra and Ceram Island, Moluccas, Indonesia.

Etymology. The name is combination of the first three letters of the genus Atya and the last four letters of the genus Caridina , alluding to its close relationship with these genera.