Consequences of sensory plasticity in fish

In a recent paper published in Proceedings of the Royal Society of London B (Chapman et al. 2010: http://rspb.royalsocietypublishing.org/content/early/2010/01/05/rspb.2009.2055.full.pdf+html) we report on the consequences of sensory plasticity in a species of freshwater fish, the guppy. Sensory plasticity is a widely documented phenomenon where animals compensate for sensory deprivation in one sense (e.g. vision) by an improvement in the performance of an alternative sense (e.g. smell). Surprisingly the consequences of sensory plasticity for important survival-related behaviours such as locating food have not been tested. In our experiments we show that fish that experience poor visual conditions (low light) in early life make a sensory ‘switch’ to a reliance on ‘smelling’ chemical cues to find food. These fish effectively compensate for difficulty in seeing food by this switch, and we find that fish reared under visually poor conditions will continue to rely on smell even when tested under standard light conditions. Our research suggests that this switch from vision to smell may help individuals to carry out foraging behaviour that is essential to their survival in a visually poor environment. Given that many human activities can affect the sensory environment animals experience (such as increased turbidity in lakes and ponds and acoustic noise in urban environments) the ‘compensatory plasticity’ we find in our study may provide a buffer that allows animals to carry out fundamental behaviours such as finding food in the face of substantial change to the sensory environment.

Thanks to Lesley Morrell for the guppy photo! (http://www.personal.leeds.ac.uk/~bgyljm/)

/Ben