Laomenes A.H. Clark, 1919

Marin, Ivan, 2009, Crinoid-associated shrimps of the genus Laomenes A. H. Clark, 1919 (Caridea: Palaemonidae: Pontoniinae): new species and probable diversity, Zootaxa 1971, pp. 1-49 : 3

Genus Laomenes A.H. Clark, 1919

Corniger Borradaile, 1915: 207 [type species: Periclimenes (Corniger) ceratophthalmus Borradaile, 1915 ] [junior homonym of Corniger Agassiz, 1831 (Pisces) , and Corniger Boehm, 1879 (Pycnogonida) ; gender masculine]. Laomenes Clark, A.H., 1919: 199 [nom. nov. for Corniger Borradaile, 1915 ; gender masculine]. — Okuno & Fujita, 2007: 115.

Parapontonia Bruce, 1968: 1148 [type species: Parapontonia nudirostris Bruce, 1968 ].

Diagnosis. Commensal shrimps associated with crinoids. Body elongated, subcylindrical. Carapace with antennal and hepatic teeth. Rostrum well developed, long and deep, with or without dorsal and ventral teeth; wide proxilateral rostral margins form well developed triangular supraocular teeth. Eyes with rounded cornea and produced apical papillae. Epistome with a pair of well developed horn-like processes (“epistomial horns”). Mandible without palp. Maxilliped II with epipod and podobranch. Maxilliped III with exopod and small arthrobranch. Pereiopod II robust, similar in shape, sometimes dissimilar in size. Dactyli of pereiopods III–V biunguiculate, with accessory tooth at middle of ventral margin, without accessory spines on anterior margin.

Included species. Laomenes amboinensis ( De Man, 1888) , L. ceratophthalmus ( Borradaile, 1915) (type species), L. cornutus ( Borradaile, 1915) , L. nudirostris ( Bruce, 1968) , L. jackhintoni ( Bruce, 2006) , L. clarki sp. nov., L. pardus sp. nov., L. tigris sp. nov.

Remarks. The genus distinctly differs from the majority of pontoniine genera by the presence of well developed triangular supraocular teeth, triangular, pointed epistomial horns and produced apical papillae on cornea of eyes. The other crinoid-associated genera, Araiopontonia Fujino & Myiake, 1970 and Unguicaris Marin & Chan, 2006 , are similar but easily distinguished. Laomenes differs from Araiopontonia by the presence of antennal tooth (vs. completely reduced in Araiopontonia ) and the presence of apical papillae on the eyes (vs. rounded cornea in Araiopontonia ); from Unguicaris by the presence of produced central papillae of the eyes (vs. rounded in Unguicaris ) and the absence of accessory spines on the anterior margin of the dactyli of pereiopods III–V.

Genus distribution. Tropical Indo-West and Central Pacific, from east coast of Africa and the Red Sea to New Caledonia, Easter Island and north to Japan.

Structure of the genus. Three groups of species can be recognised within the genus: “ L. amboinensis ”, “ L. jackhintoni ” and “ L. ceratophthalmus . ”