The eumedonid file: A case study of systematic compatibility using larval and adult characters (Crustacea: Decapoda: Brachyura)

Abstract

Eumedonid crabs have an unusual ecology. They are a specialized group of brachyurans, which are wholly symbiotic with echinoderms. Consequently, this taxon has received much attention from carcinologists, but consensus on the familial status of these crabs has not been reached. Eumedonids have been variously regarded as a subfamily of the Parthenopidae, as pilumnids and as a distinct family. The taxonomic position of the Eumedonidae is appraised using available first zoeal and adult characters. The validity of this family status is challenged, and the present study shows that this group of crabs cannot be distinguished from the pilumnids and therefore supports the view that the eumedonids are a subfamily of the Pilumnidae.