Some Observations on the Thalassinid Shrimp, Eutrichocheles Modestus (herbst, 1796) from South Vietnam (thalassinidea, Axiidae), with Remarks on Eutrichocheles Crosnieri Ngoc-Ho, 1998

The rare thalassinid shrimp, Eutrichocheles modestus (Herbst, 1796) is now recorded from South Vietnam. It was previously collected in Thailand and Malaysia, and was dealt with in Ngoc-Ho (1998) and Ngoc-Ho et al. (2005).The Vietnamese specimens are described in detail and variations are discussed. They are compared with specimens from Thailand and Malaysia, and with the female holotype of Eutrichocheles crosnieri Ngoc-Ho, 1998, also from Vietnam. Additional remarks, especially on the status of the latter species, are presented.A note on the habitat, fishery, and economic importance of E. modestus in Vietnam is provided. This study shows that the only female of E. modestus from Vietnam, as well as the one from Thailand, differ from the holotype of E. crosnieri by certain features, and no males examined can be assigned to this latter species. The two species are here kept separate, pending a future study of additional material, especially from the type locality of E. crosnieri.