The sexual regime of deep-water shrimps (Decapoda, Pandalidae) in the Southern Tyrrhenian Sea (Central Mediterranean)

The sexuality of four species of deep-water pandalid shrimps, collected in the southern Tyrrhenian Sea during an experimental trawl survey, was studied. Sex was determined by the presence or absence of an appendix masculina on the second pair of pleopods. The relationship between shrimp size (carapace length) and the relative length of the appendix masculina was used to establish that the four species are dioecious. Moreover, descriptive statistics of the size (CL) in each species studied were calculated separately for males and females.