Phylogenetic analysis of the Pinnotheridae (Crustacea, Brachyura) based on larval morphology, with emphasis on the Dissodactylus species complex

Abstract

Comparative larval morphology was used to elucidate phylogenetic relationships within the Pinnotheridae and the Dissodactylus species complex. Within the family, seven zoeal and six megalopal characters suggested two equally parsimonious phylogenetic hypotheses for pinnotherid larvae, both with Ostracotheres tridacnae representing the sister group for the Dissodactylus complex. Results indicated that the genus Pinnotheres is a polyphyletic taxon, and that the traditional subfamilial arrangement comprises paraphyletic taxa within the subfamilies Pinnotherinae and Pinnothereliinae. Certain evidence has suggested that Fabia and Juxtafubia should be excluded from the Pinnotherinae and placed into the Pinnothereliinae. Larval and adult morphology suggested that Pinnotheres politus should be included within Tumidotheres. The phylogenetic analysis within the Dissodactylus complex involved one zoeal and 16 megalopal characters. Results suggested a single phylogenetic hypothesis based on larval morphology. Combining adult morphology with larval evidence resulted in two equally parsimonious phylogenetic hypotheses, one of which agreed with a previously suggested hypothesis based only on adult characters.