PHYLOGENETIC-RELATIONSHIPS AMONG GAMMARIDEAN FAMILIES AND AMPHIPOD SUBORDERS

The phylogenies of gammaridean families and amphipod suborders have been investigated by cladistic methods. Sixteen morphological characters were used in this analysis. Five independent lineages identified from this analysis were Gammaridae, Crangonyctidae, Pontogeneiidae, Synopiidae plus Stegocephalidae, and one comprising the other groups considered in this study. The Talitroidea, consisting of Hyalidae and Talitridae, was monophyletic. Three families (Podoceridae, Caprogammaridae and Caprellidae), which all have a reduced abdomen, proved to be monophyletic, and this result suggests that the combination of the Corophioidea with Caprellidea would be monophyletic. The Hyperiidea showed a close affinity with leucothoid members such as Amphilochidae and Stenothoidae. The present phylogenetic scheme is compared with previous hypothetical schemes.