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Effect of elevated winter-spring water temperature on sexual maturation in photoperiod manipulated stocks of rainbow trout (Oncorhynchus mykiss)

Citation

Wilkinson, RJ and Longland, R and Woolcott, H and Porter, MJR, Effect of elevated winter-spring water temperature on sexual maturation in photoperiod manipulated stocks of rainbow trout (Oncorhynchus mykiss), Aquaculture, 309, (1 - 4) pp. 236 - 244. ISSN 0044-8486 (2010) [Refereed Article]

DOI: doi:10.1016/j.aquaculture.2010.08.023

Abstract

The use of artificial lighting on salmonids has successfully reduced levels of early sexual maturation, however variable results between seasons have been observed. Therefore, this work investigated the impact of photoperiod and winter-spring water temperature on maturation in populations of female rainbow trout. Fish were maintained in tanks (from April 2006 to May 2007) under two photoperiod regimes-(1) simulated natural annual photoperiod cycle (41°S) and (2) approximately 5. week advanced annual photoperiod cycle. Two temperature treatments were also employed-(1) simulated natural annual temperature cycle (8-18 °C) and (2) simulated natural annual temperature cycle with elevated mean winter-spring water temperatures (maximum 5 °C elevation). In photoperiod advanced fish, elevated water temperature resulted in a significant increase in maturation rate (39.8 ± 3.3% and 17.5 ± 5.3% for the elevated temperature and natural temperature group, respectively). Maturation rates in fish held under natural photoperiod conditions were significantly higher irrespective of water temperature (79.4 ± 6.6% and 73.3 ± 0.1% for the elevated temperature and natural temperature group, respectively). In addition, gonadosomatic index was significantly higher in photoperiod advanced fish, irrespective of water temperature, at the conclusion of the experiment, with 32% of these fish undergoing ovulation and significantly reduced plasma levels of 17ß-estradiol just prior to ovulation. Significantly greater wet weight, condition factor, specific growth rate and plasma insulin-like growth factor-I were measured in PIT-tagged fish which went on to mature at the conclusion of the experiment compared to those which remained immature. This study demonstrates that elevated winter-spring water temperature results in increased rates of maturation in photoperiod-manipulated stocks of rainbow trout and has important implications for application of artificial lighting on commercial farms which may experience variation in water temperature from year to year. © 2010.

Item Details

Item Type:Refereed Article
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 Fin Fish (excl. Tuna)
Author:Wilkinson, RJ (Dr Ryan Wilkinson)
Author:Longland, R (Mr Ryan Longland)
Author:Woolcott, H (Ms Hannah Woolcott)
ID Code:65224
Year Published:2010
Web of Science® Times Cited:11
Deposited By:NC Marine Conservation and Resource Sustainability
Deposited On:2010-10-18
Last Modified:2011-03-24
Downloads:0

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