J. Fish Biol. 73, 728–731 (2008)

When mothers warn their daughters that boys are after only one thing, a meal probably isn't what they have in mind. However, male fish of one species have been observed enticing females of a closely related species to spawn so that they can consume their eggs.

Suzanne Gray of Simon Fraser University in Burnaby, Canada, and her colleagues report four instances in which a male Telmatherina sarasinorum was seen courting a female T. antoniae. The females were seen quivering, which is normally indicative of egg release. When each female finished quivering, the male immediately turned around and tried to eat her eggs.

Gray terms this behaviour 'sneaky egg-eating' and suggests it may have arisen in part because of a paucity of rich nutritional sources in Lake Matano, the Indonesian waterway where the fish live.