The male of <i>Dinemoleus indeprensus</i> Cressey & Boyle, 1978 with a brief overview of sexual dimorphism in the family Pandaridae (Copepoda: Siphonostomatoida)

The male of Dinemoleus indeprensus reported, to date, only on the megamouth shark, Megachasma pelagios, is described in detail. It has a 2-segmented abdomen, the outer margin of the distal endopodal segment of leg 3 is unmodified, and leg 4 has a 1-segmented exopod but the endopod is indistinctly 2-segmented. This combination of character states is unique in the family. Males are now known for 20 of the 22 genera currently accepted as valid within the Pandaridae, so a brief overview of sexual dimorphism within the family is presented and a key to genera, based on males, is provided to facilitate identification in the future.