Taxonomic revision of the Amphilius uranoscopus group (Teleostei: Siluriformes) in Kenya, with the description of a new species from the Athi River

Abstract

The taxonomy of the Amphilius uranoscopus group in Kenya is revised. Amphilius athiensis n. sp. is described from the Galana River basin, and Amphilius grandis and Amphilius krefftii are removed from synonymy with A. uranoscopus and redescribed. All three species are assigned to the Amphilius uranoscopus group, which is distinguished from other species of Amphilius by the absence of a crenellated epidermal fold at the base of the caudal fin, having 8+9 (i,7,8,i) principal caudal-fin rays, usually having 36 to 42 total vertebrae, and by having the leading pterygiophore of the dorsal fin intercepting the vertebral column at the first, second or third post-Weberian vertebra. Six species are recognized in the A. uranoscopus group (A. athiensis n. sp., Amphilius chalei, Amphilius cryptobullatus, A. grandis, A. krefftii, and A. uranoscopus). They are distinguished from each other by coloration, barbel length, caudal fin shape, body and caudal peduncle depth, number of vertebrae, and by the development of their bilateral bony swimbladder capsules.