Two new species of Metabranchipus Masi, 1925 (Anostraca: Branchipodidae)

Abstract

Two new species of fairy shrimp, Metabranchipus rubra and Metabranchipus prodigiosus, are described from KwaZulu-Natal in South Africa. Both species are separated from M. patrizii by the form of the male second antennae. Metabranchipus prodigiosus is readily separable from all other fairy shrimp by the presence of a large, bifurcated, prehensile appendage that originates between the gonopod bases in the males, and an armored gonopore in the females. The male exhibits the most elaborate amplexial morphology ever observed within Anostraca, whereas the female has no complimentary amplexial specialization, combined with an armored gonopore. We suggest that M. prodigiosus is engaged in a sexual arms race, wherein the females are under selection to avoid mating. The history of Branchipodidae is discussed. The seven branchiopodid genera are reviewed and a key is provided, with a checklist of the described species. © 2012, The Crustacean Society.