 The actual number is labelled with some uncertainty because of the many undescribed species and the extreme variation among some species, making the task of delimiting them very complex.Except for four species ("Astatotilapia calliptera", "Coptodon rendalli", "Oreochromis shiranus" and "Serranochromis robustus"), all cichlids in the lake are endemic to the Malawi system, which also includes nearby smaller Lake Malombe and the upper Shire River.Many of these have become popular among aquarium owners due to their bright colors.