A new species of Slender Stonebasher within the Hippopotamyrus ansorgii complex from the Cunene River in southern Africa (Teleostei: Mormyriformes)

Abstract

Previous work has revealed that Hippopotamyrus ansorgii (Boulenger, 1905) is a
species complex, with specimens from the Upper Zambezi system (Caprivi Strip in
Namibia) that are well differentiated from the Angolan type specimens. Here, we
sampled the Cunene River, one of several possible type rivers for H. ansorgii, on
the border between Namibia and Angola. The specimens are morphologically
differentiated from the six other known morphs within the H. ansorgii species
complex, including the types and H. szaboi. The electric organ discharge of the
Cunene specimens has a different pulse waveform and associated amplitude spectra
to that of the three Upper Zambezi system morphs of the species complex. The
Cunene specimens are genetically distinct, but relatively closely related to other
taxa of the H. ansorgii complex, such as the Upper Zambezi system morphs.
We recognize the Lower Cunene morph as the new species, Hippopotamyrus
longilateralis sp. nov.