Biological data are presented for the poorly known bristly catshark Bythaelurus hispidus based on specimens collected from the by-catch of the commercial deep-sea shrimp trawl fishery operating in the Arabian Sea at depths of 200-500 m off the south-west

Bythaelurus naylori sp. n. is described based on 41 specimens collected from seamounts in the southwestern Indian Ocean. The new species can be separated from all other Bythaelurus species by a combination of distinctly enlarged dermal denticles on

A new deep-water catshark, Bythaelurus bachi, is described based on 44 specimens caught on the southern Madagascar Ridge in the southwestern Indian Ocean. The new species is the only stout-bodied Bythaelurus with oral papillae in the region and is distinguished