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Factors affecting the feeding response of larval southern bluefin tuna, Thunnus maccoyii (Castelnau, 1872)

Citation

Hilder, PE and Cobcroft, JM and Battaglene, SC, Factors affecting the feeding response of larval southern bluefin tuna, Thunnus maccoyii (Castelnau, 1872), Aquaculture Research, 48, (6) pp. 2752-2766. ISSN 1355-557X (2017) [Refereed Article]

Copyright Statement

Copyright 2016 John Wiley & Sons Ltd

DOI: doi:10.1111/are.13108

Abstract

Southern bluefin tuna, Thunnus maccoyii, are cultured in Australia following collection of wild juveniles. Hatchery culture from egg is in the experimental stage. High early mortality has hindered the production of quality juveniles in the hatchery. This study investigated the visual capacity of T. maccoyii during early larval ontogeny in order to describe the best larval rearing conditions to produce high-quality seed stock. Functional visual ability, determined through behavioural experimentation, identified the effect of light intensity, prey density, turbidity, tank colour and turbulence on the feeding response. Larvae were visually challenged to feed under a range of conditions in short-duration (4 h) feeding experiments. Feeding performance was measured as the proportion of larvae feeding and the intensity of feeding. First-feeding performance was positively affected by increasing prey density and lower turbidities and unaffected by light intensity, tank colour, turbulence, prey size and larval density. The key findings from feeding experiments on 6 and 9 dph larvae was that as T. maccoyii aged, lower light intensities and higher prey densities significantly increased feeding performance. In addition, the study has identified that high light intensity and high air-driven turbulence induced significant mortality. The proficient first-feeding response indicated that early mortality common in culture is unlikely to be associated with a failure to initiate feeding. Our findings show the use of low light intensity has the potential to significantly improve survival and feeding response during the first two critical weeks of culture, when the major bottleneck in hatchery production is currently experienced.

Item Details

Item Type:Refereed Article
Keywords:marine fish larvae, light intensity, turbulence, prey density, larval mortaliy, first-feeding
Research Division:Agricultural and Veterinary Sciences
Research Group:Fisheries Sciences
Research Field:Aquaculture
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - Aquaculture
Objective Field:Aquaculture Tuna
Author:Hilder, PE (Mrs Polly Hilder)
Author:Cobcroft, JM (Dr Jennifer Cobcroft)
Author:Battaglene, SC (Associate Professor Stephen Battaglene)
ID Code:118117
Year Published:2017
Deposited By:Fisheries and Aquaculture
Deposited On:2017-07-04
Last Modified:2017-12-13
Downloads:0

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