Crinoid-associated shrimps of the genus Laomenes A.H. Clark, 1919 (Caridea: Palaemonidae: Pontoniinae): new species and probable diversity

Abstract

Three new species of the genus Laomenes A.H. Clark are described as symbionts of feather stars (Crinoidea: Comatulida) from shallow waters of Nhatrang Bay, Vietnam. Including these new species, the genus comprises 8 species and can be arranged into 3 suggested groups of species. The “L. amboinensis” species group with 4 species, L. amboinensis (De Man, 1888), L. cornutus (Borradaile, 1915), L. clarki sp. nov. and L. pardus sp. nov., characterized by the presence of ventral rostral teeth, distoventral spines on propodus of pereiopod III and a fixed tooth on distolateral margin of uropodal exopod. The “L. jackhintoni” species group includes 2 species, L. jackhintoni (Bruce, 2006) and Laomenes tigris sp. nov., characterized by the absence of ventral rostral teeth, extremely elongated apical papilla on cornea of eyes, the presence of fixed tooth on exopod of uropod, the absence of distoventral spines on propodus and the presence of large accessory tooth on dactylus of pereiopod III. The “L. ceratophthalmus” species group includes 2 species, L. ceratophthalmus (Borradaile, 1915) and L. nudirostris (Bruce, 1968), characterized by the absence of ventral rostral teeth and distoventral spines on propodus of pereiopod III, the presence of small accessory tooth on dactylus of pereiopod III, tiny marginal dorsal spines on telson and the absence of a fixed distolateral tooth on exopod of uropod. Remarks and a key for all species of the genus as well as a discussion of the undescribed diversity of the genus are given.