Sur un Mysidace pelagique peu connu: Euchaetomeropsis merolepis Illig, 1908

The capture of a mysid, an adult female, of the genus Euchaetomeropsis in the center of the western Mediterranean made a re-description of Euchaetomeropsis merolepsis, species to which we have provisionally referred our specimen, necessary. We have described the whole animal and different organs or appendages (eye; labrum; cephalic, thoracic and abdominal appendages; telson) insisting more especially on the following characters: on the one hand, the structure of the pars molaris of the mandible which distinguishes Euchaetomeropsis pacifica, second species of the genus, from E. merolepis; on the other hand, the morphology of the endopod of the uropod and its proportions to the telson, about which contradictory statements occur in the literature. Our specimen does not correspond perfectly to any of the earlier descriptions, but additional observations are necessary in order to decide whether it belongs to a third species. This new record proves that the genus Euchaetomeropsis, bathypelagic in habit, occurs in the three oceans and in the Mediterranean.