Phylogenetic and systematic position of the Penaeus subgenus Litopenaeus (Decapoda: Penaeidae)

Abstract

Ten synapororphies are demonstrated to separate Ihe closed thelyca Penaeus subgenera Litopenaeus Fenneropenaeus. Marsupenaeus. Melicerlus. and Penaeus s.s) from the open thelycum subgcnus Litopenaeus. Thephylogenelic psilion of Litopenaeus was investigated within the context of Ihe tribe Penaeae (genera Funchalia. Heteropenaeus. Pelagopenaeus and Penaeus: Burkenroad 1936). A cladistic analysis using general genital characters positioned Litoperanaeus basal within the tribe; cladistic analysis based upon genital and key somatic characters allowed several hypotheses of relationships to be developed. The first of these hypotheses one compatible with the current classification, juxtaposed Litoperanaeus and the closed thelyca Penaeus subgenera as sister laxa, proposing that the Stem Litopenaeus species underwent reversals to ancestral character Stales (atavisms). The other hypotheses were congruent wilh the hypotheses based upon genital characters.