Publication Abstract

Artificial dietary regime may impair subsequent foraging behaviour of hatchery-reared turbot released in to the natural environment

Artificial dietary regime may inpair subsequent foraging behaviour of hatchery-reared turbot released in to the natural environment

T. Ellis, B.R. Howell and R. N. Hughes

When offered a size range of shrimp Crangon Cangon, fewer naive reared turbot Scophthalmus maximus fed than did wild fish, and those that fed took smaller prey. Analysis of feeding behaviour indicated differences between wild and naive reared fish in the motivation to feed on novel prey and in prey recognition and capture efficiency. Feeding efficiency and motivation increased with experience and reared fish achieved the feeding rate of wild fish within the 9 days of the experiment. The 'creep' style of approach to shrimp was innate to naive reared turbot. A comparative feeding experiment confirmed that experienced reared fish ate more prey than naive reared fish. Naive reared turbot selected pellets and attacked stones preferentially to shrimp, in contrast to wild and experienced reared fish, which selected shrimp. Stones were attacked due to the memory of pellet-like visual characteristics and this behaviour persisted in some reared fish for at least 6 weeks, illustrating a cost of memory in which changing environmental conditions cause previously learnt information to become misleading. The experimental data also demonstrated that differences may arise in the prey and feeding behaviour of wild and naive reared fish, but that such differences diminish with experience.

Reference:

T. Ellis, B.R. Howell and R. N. Hughes, 2002. Artificial dietary regime may inpair subsequent foraging behaviour of hatchery-reared turbot released in to the natural environment. Journal of Fish Biology, 61: 252-264.

T. Ellis*, B.R. Howell* and R. N. Hughes

Journal of Fish Biology, 61: 252-264