| Abstract |
Descritpions are given of some zoeal stages (I-V) of Stenopus spinosus Risso 1826 (Crustacea, Decapoda: Stenopodidea) from plankton collected off the Algerian coast.These larvae are compared to the same species but from other localities.They show great diversity in general appearance: in the same genus there is a wide range of detailed structure in almost all species.The genus Stenopus Latreille has a circumtropical distribution and the Atlantic Mediterranean species, Stenopus spinosus, and the Indopacific one, Stenopus hispidus, are vicariant, relicts from the Mesogean sea.From a TAXONOMY point of view, the Stenopodidea constitute a group with doubtful affinity.From a larval point of view the form and the structure of the telson is considered very important particularly the second spine reduced to a fine hair.This hair-like second telson process is not present in any Dendrobranchiata, Caridea, Astacidea and Palinura, but it is common in Stenopodidea, Thalassinidea and Anomura; there appears to be some larval affinities with reptant groups.The Stenopodidea should be considered as an independent group branching off the line which later gave rise to the Thalassinidea and Anomura.It seems likely that the origin and affinities of Stenopodidea should be found among reptant groups |
