First zoeal stage of Processidae (Decapoda, Caridea): review and new descriptions of Emphasis Type="Italic"Ambidexter symmetricus/Emphasis Manning and Chace 1971 and Emphasis Type="Italic"Processa fimbriata/Emphasis Manning and Chace 1971

摘要

This study reviews the morphology of the first zoeal stage of the pantropical and subtropical marine shrimps of the family Processidae. We present the first descriptions of the zoea I of Ambidexter symmetricus and Processa fimbriata and compare them with available published descriptions, in order to detect patterns to differentiate the genera. Among the species of Processidae, the zoea I of Ambidexter can be differentiated by the presence of a rostrum, and the resemblance to Nikoides and Processa, previously reported for adults, is now confirmed for the larval morphology. Based on the new descriptions, A. symmetricus and A. panamensis can be easily separated by four independent larval characters: anterior tubercle on the carapace (present in A. panamensis and absent in A. symmetricus), the antennal scale (segmented distally in A. panamensis and unsegmented in A. symmetricus), and the anal spine and second pereiopod (absent in A. panamensis and present in A. symmetricus). P. fimbriata can be separated from the other 11 species of Processa by means of two larval characters: 4 aesthetascs on the exopod of the antennules, and the presence of an anal spine.