SENSORY ABILITY AND FORAGING BEHAVIOUR OF ELECTROSENSITIVE FISH

Elasmobranchs (sharks, skates and rays) rely on electroreception as a near-distance sense for detecting bioelectric fields emitted by their prey. The physiology of this sense has been studied extensively, however its associated behaviour has been largely neglected. There is an urgent need for more information to assess adequately the possible effects of growing numbers of artificial electric fields around coasts associated with offshore renewable energy developments.

This research investigated the electro-receptive foraging behaviour of the small spotted catshark (Scyliorhinus canicula) using artificial prey-type electric fields under laboratory conditions. The research tackled three areas: 1. Comparison of male and female electro-receptive foraging behaviour given that the sexes of S. canicula have different behavioural strategies resulting in sexual segregation (see Sexual Segregation project). Are such differences reflected in electro-receptive behaviour? 2. Investigation of whether catsharks are able to alter their behaviour towards electric fields dependent on whether they are rewarded for responding to the fields or not. This should give an idea of whether elasmobranchs would waste valuable time ‘hunting’ electric cables rather than focusing their efforts on natural prey. 3. Whether catsharks show preferences for certain electric fields by presenting them with two fields at once. This includes different DC currents, DC and AC fields, and artificial and natural fields. A related question is whether  catsharks simply detect whether an electric field is present or not (on-off switch) or whether they are able to differentiate between electric fields.

People involved: Joel Kimber (PhD Student, MBA & Cranfield University), Professor David Sims (MBA), Dr Andrew Gill (Cranfield University).

Funding: Fisheries Society of the British Isles Ph.D Studentship.