Stonemover Cichlid Retroculus lapidifer

The Stonemover Cichlid is native to fast-flowing rivers and rapids of southeastern Brazil. It can grow to 20cm long.

A little like a cross between a goby and an eartheater, it sits propped up on its fins on the sandy riverbed taking in substrate with insect larvae and expelling sand from its gills. When nesting, the fish carry small stones in their mouths to build a gravel nest - hence the name stonemover.