Ptychochromis is a genus of cichlids endemic to rivers and lakes in Madagascar. One species, like Ptychochromis grandidieri can also be seen in brackish water. Most species in this genus are threatened, and Ptychochromis onilahy is probably extinct. Most reach a length of 12–15 cm (4.7–5.9 in), but Ptychochromis insolitus only reaches 5.5 cm (2.2 in), while Ptychochromis grandidieri and Ptychochromis oligacanthus reach 21–25 cm (8.3–9.8 in).