The nurseryfishes or forehead brooders are a family (Kurtidae) of fish that are notable for carrying their egg clusters on hooks protruding from the forehead (supraoccipital) of the males. The family consists of just two species in the single genus Kurtus.
In addition to the egg hook, the kurtid gas bladder is enclosed in a tubular bony structure evolved from the ribs. In both species the back is elevated into a hump shape.
The nurseryfish, Kurtus gulliveria (Castelnau, 1878), occurs in mangrove swamps, estuaries and slow-moving turbid rivers of Australia and New Guinea. It can grow to 63 cm.
The Indian hump head, Kurtus indicus (Bloch, 1786) is found in marine waters from the Coromandel coast of India to Borneo. It is known to reach only 12.6 cm in length.
Despite their unusual reproductive habits, little is known about these species; they do not survive long in aquaria. Tim Berra of Ohio State University has published several papers.