Domestication and behaviour in fish

Abstract

One of the major objective of domestication is the selection of lines with low aggressiveness and a high growth potential. Analyses of domesticated animals traits often illustrate numerous changes in behaviour due to rearing environment. However there are few reports of these changes in fish. In the present paper, we first describe how behaviour is affected by rearing and then discuss how sensory organs and behavioural abilities are modified during development under breeding conditions.

Rearing conditions modify feeding behaviour particularly because food distribution do not necessary follow biological rhythm and food is often available in larger amount compared to wild-type situations. In particular food distribution mode may favour aggressiveness. Rearing conditions (stream, fish density…) are also susceptible to modify spatial distribution of fish and relationship between fish in their closed environment. In particular, fish often reduce their inter-individual distances which may also have detrimental influences on their aggressiveness.

Several behavioural abilities seem to be affected by development in breeding conditions and this appears to be related to modification of sensory organs. This includes modification of the lateral line system, eye and smell. These modifications are often associated to a lowering of watchfulness threshold which in turn modifies behaviour and particularly escape responses from potential predators. A modification of chromatic adaptation has also been shown for flat fishes.

In conclusion, the analysis of behavioural modifications is of utmost importance to identify indicators of domestication progress which must be taken into account to guarantee cultured fish welfare and thus rearing sustainability.