THE ANOSTRACAN GENUS BRANCHINELLA (CRUSTACEA, BRANCHIOPODA), IN NEED OF A TAXONOMIC REVISION - EVIDENCE FROM PENILE MORPHOLOGY

Three morphologically different penile types discovered in branchinell ids from Botswana are compared with literature information on congener s. The striking differences among penile structures in Branchinella on donguae, B. ornata and the halobiontic B. spinosa raise doubts about t heir congeneric status. Penis morphology in B. ondonguae corresponds w ith the most common configuration in branchinellids, but it is largely deviant in the other two. Branchinella ornata shares penile structure s with Dendrocephalus, while basal parts in B. spinosa reflect affinit y with chirocephalids. A considerable general morphological variabilit y in Branchinella, not met in any other anostracan genus, may reflect the antiquity of the group, or else poor taxonomy. Large intra-branchi nellid variability and vague generic boundaries, even when considering the usually conservative penile structures, stress the need of a thor ough revision of the entire family of the Thamnocephalidae. (C) 1997 T he Linnean Society of London.