File(s) under permanent embargo
Behaviour of rainbow trout (Oncorhynchus mykiss) under defensible and indefensible patterns of food delivery
journal contribution
posted on 2023-05-17, 02:54 authored by Saeed Heydarnejad, M, Gary PurserGary PurserThe goal of this study was to investigate the behaviour of rainbow trout (n = 30), Oncorhynchus mykiss, in small raceways when either self-feeders (T2) or hand-feeding (t2) were used. The method of food delivery in T2 was defensible while that of t2 was indefensible. Fish in both raceways were subjected to restricted feeding (RF) for 25 days. Food was available in the morning (09:00-10:00) in the downstream area and in the afternoon (16:00-17:00) in the upstream area of the raceways. The results showed that the behaviour of rainbow trout was significantly different under interference competition (T2) for food compared with that under scramble competition (t2). RF in T2 fish limited food availability to meal times when feeding rewards were available while t2 fish only responded to the location of food delivery. The aggressive fish in T2 were dominant, and t2 fish at high densities showed intense social interactions under the indefensible pattern of food distribution; these interactions did not dampen to a minimum level to suppress the development of dominance hierarchies. Further, the stocking density did not break down the dominance hierarchies between the T2 fish. This suggests that decreased efficiency in the search for food or inefficient foraging, induced by interference competition at high densities, affected the behaviour of rainbow trout.
History
Publication title
Chinese Journal of Oceanology and LimnologyVolume
28Issue
4Pagination
749-755ISSN
0254-4059Department/School
Institute for Marine and Antarctic StudiesPublisher
Zhongguo Kexueyuan, Haiyang YanjiusuoPlace of publication
ChinaRights statement
Copyright 2010 Chinese Society for Oceanology and Limnology, Science Press, and Springer-Verlag Berlin HeidelbergRepository Status
- Restricted