Cannibalism in teleost fish

1.	Cannibalistic behaviour in fish is reviewed here for the first time.
2.	Cannibalism has been recorded in 36 out of 410 teleost families according to the published literature, but is considered to be more widespread than this. Finding examples of cannibalism is not difficult, and it may be more interesting to look for taxa in which the behaviour does not take place.
3.	The families that have provided the most information include the Engraulididae, Esocidae, Poeciliidae, Gasterosteidae, Percidae and Cichlidae.
4.	Cannibalism has been classified into seven types, depending on life-history stage, age difference between cannibal and prey, and whether or not they are related.
5.	Although in captive populations, cannibalism tends to increase with increasing density and decreasing food availability, its role in population regulation has not been unequivocally demonstrated in any wild population, and obtaining the necessary data presents a formidable challenge to fish ecologists.
6.	Cannibalism is of some economic importance in aquaculture, but its impact can be reduced relatively easily, by frequent grading to reduce size variability.
7.	The main proximate advantage conferred by cannibalism is assumed to be nutritional. In an ultimate sense the behaviour may have evolved as a particularly effective competitive strategy.
8.	Finally, it is considered that cannibalism deserves more attention from fish biologists. Investigations, however, should recognize the different types of cannibalistic interaction, and, in particular, should explore the different implications of kin and nonkin cannibalism