A new species of Nebalia (Crustacea, Leptostraca) from Unguja Island (Zanzibar), Tanzania, East Africa, with a phylogenetic analysis of leptostracan genera

Nebalia brucei sp. nov, is described from specimens taken in traps from Unguja Island (Zanzibar), Tanzania, East Africa. The species is characterized by the following unique combination of characters: a short and broad rostrum; a carapace that is large compared to overall body size and that covers pleonite 4; a basally narrow compound eye; and acutely pointed denticles at the dorsal margin of pleon segments 6 and 7. Cladistic analyses of the relationships of the seven recognized leptostracan genera resulted in two hypotheses. One tree has Nebaliopsis as sister group to the remaining leptostracans and supports the monophyly of Nebaliidae. The other tree has Paranebalia as sister group to the remaining leptostracans and Nebaliidae as paraphyletic with respect to Nebaliopsis. Both trees contain a Nebalia/Dahlella/Sarsinebalia clade.