The effects of behavioural development on search tactics of predatory marine fish.

Joshua Filer

University of Leicester
(based at the Marine Biological Association of the United Kingdom)

Supervisors: Dr David Sims (Marine Biological Association of the United Kingdom)
Prof Paul Hart (University of Leicester)

Given the complexity and dynamic nature of ecosystems and particularly the marine environment, a key problem facing predators is that of locating sufficient resources (e.g. prey, mates, and shelter). So how do marine predators lacking complete knowledge of their environment locate resources? As locating food is an important factor that determines the evolutionary fitness of an animal, various theoretically optimal models of movements of predators whilst searching for food have been postulated. However, despite considerable attention, empirical tests of such models are few and incomplete for marine predatory fish. Generally, little is known about the search tactics employed by marine predators and even less is known about their development. Therefore, my research aims to shed some light on the search tactics used by marine fish and how they develop with age and experience. To do this I have been conducting laboratory experiments to investigate the foraging behaviour of the small spotted catshark (Scyliorhinus canicula) at various life stages. These laboratory experiments have been supplemented by field tracking of free-ranging adults in the wild using various acoustic telemetry techniques. In addition to these empirical elements appropriate simulations of predator movements whilst foraging in different situations will be undertaken. Understanding fish movements and how they change with time and under different conditions is directly relevant to conservation and sustainable fisheries management initiatives.

Analysing the movements of a small spotted catshark