Manuscaris, Komai & Tsuchida, 2015

Komai, Tomoyuki & Tsuchida, Shinji, 2015, New records of Alvinocarididae (Crustacea: Decapoda: Caridea) from the southwestern Pacific hydrothermal vents, with descriptions of one new genus and three new species, Journal of Natural History (J. Nat. Hist.) 49, pp. 1-36 : 22-23

Manuscaris gen. nov.

Type species

Manuscaris acuminatus sp. nov.

Composition

Monotypic

Diagnosis

Rostrum narrowly triangular in dorsal view, slightly overreaching distal margin of first segment of antennular peduncle; dorsal margin sharply carinate, armed with row of conspicuous teeth, posteriormost tooth located just posterior to rostral base; ventral margin nearly flat, with minute denticle subterminally. Carapace with low, blunt postrostral carina not extending to midlength; antennal tooth acuminate, with small lobe ventromesial to its base; pterygostomial tooth strong, acuminate; anterior part of branchial region not inflated. Third to fifth pleonal pleura at least with posteroventral tooth. Telson with dorsolateral spines in linear row; posterior margin convex, with row of plumose setae flanked by two pairs of lateral spines. Eyes fused, though shallow median notch evident; anterior surface of each eye flat, unarmed. Antennular stylocerite well separated from first peduncular segment. Antenna not forming operculate structure (see Martin and Hessler 1990); antennal scale with sharp distolateral tooth clearly separated from lamella; no transverse suture extending mesially from base of distolateral tooth. First maxilliped with rudimentary bud of exopodal flagellum. First pereopod with well-developed grooming apparatus on carpus consisting of patch of setae and one small spine. Second pereopod with spine on ischium. Third pereopod shorter than fifth pereopod; dactyli with accessory spinules on flexor margins arranged in two rows; meri of third and fifth pereopods unarmed; ischia of third pereopods with two spines. No strap-like epipods on third maxilliped to fourth pereopods. Appendix interna of fourth pleopod without terminal cluster of coupling hooks. Uropodal exopod with one spine just mesial to sharp posterolateral tooth; protopod terminating posterolaterally in sharp tooth.

Remarks

Manuscaris gen. nov. appears to be close to a group of genera that includes Alvinocaridinides , Shinkaicaris , Opaepele , Chorocaris and Rimicaris based on sharing the following apparently apomorphic characters: rostrum more or less reduced in length with reduced ventral limb; eyes broadly fused with shallow median notch, each anterior surface rather flat and unarmed; dactyli of third to fifth pereopods each with accessory spinules arranged in two or more rows; and meri of third to fifth pereopods devoid of spines. Nevertheless, the new genus is excluded from this group by the dorsolateral spines on the telson arranged in a linear row and the presence of spines on the ischia on the third and fourth pereopods, which are presumably plesiomorphic characters (cf. Komai and Segonzac, 2005).

Etymology

A combination of the name of the type locality (Manus Basin) and the Greek caris (= shrimp). Gender : masculine .