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Behaviour of rainbow trout (Oncorhynchus mykiss) under defensible and indefensible patterns of food delivery


Saeed Heydarnejad, M and Purser, GJ, Behaviour of rainbow trout (Oncorhynchus mykiss) under defensible and indefensible patterns of food delivery, Chinese Journal of Oceanology and Limnology, 28, (4) pp. 749-755. ISSN 0254-4059 (2010) [Refereed Article]

Copyright Statement

Copyright 2010 Chinese Society for Oceanology and Limnology, Science Press, and Springer-Verlag Berlin Heidelberg

DOI: doi:10.1007/s00343-010-9935-z


The 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.

Item Details

Item Type:Refereed Article
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Aquaculture
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - aquaculture
Objective Field:Aquaculture fin fish (excl. tuna)
UTAS Author:Saeed Heydarnejad, M (Mr M. Heydarnejad)
UTAS Author:Purser, GJ (Associate Professor John Purser)
ID Code:64407
Year Published:2010
Deposited By:NC Marine Conservation and Resource Sustainability
Deposited On:2010-07-27
Last Modified:2015-11-04

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