Pseudotropheus ater is a species of cichlid endemic to Lake Malawi where it is only known from around Chinyamwezi Island and Chinyankwazi Island. It prefers areas with rocky substrates at depths of from 3mto15mm (10feetto49feetm) where it grazes from the rock surfaces. This species can reach a length of 8.1cm (03.2inches) SL. It can also be found in the aquarium trade.