Reproductive dynamics and potential annual fecundity of South Pacific albacore tuna (Thunnus alalunga)
Farley, Jessica H., Williams, Ashley J., Hoyle, Simon D., Davies, Campbell R., and Nicol, Simon J. (2013) Reproductive dynamics and potential annual fecundity of South Pacific albacore tuna (Thunnus alalunga). PLoS ONE, 8 (4). e60577. pp. 1-16.
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Abstract
The reproductive biology of albacore tuna, Thunnus alalunga, in the South Pacific Ocean was investigated with samples collected during broad-scale sampling between 2006 and 2011. Histology was done in a single laboratory according to standard protocols and the data analysed using generalized linear mixed-effects models. The sex ratio of albacore was female biased for fish smaller than approximately 60 cm FL and between 85 and 95 cm, and progressively more male biased above 95 cm FL. Spawning activity was synchronised across the region between 10°S and 25°S during the austral spring and summer where sea surface temperatures were ≥24 °C. The average gonad index varied among regions, with fish in easterly longitudes having heavier gonads for their size than fish in westerly longitudes. Albacore, while capable of spawning daily, on average spawn every 1.3 days during the peak spawning months of October to December. Spawning occurs around midnight and the early hours of the morning. Regional variation in spawning frequency and batch fecundity were not significant. The proportion of active females and the spawning fraction increased with length and age, and mature small and young fish were less active at either end of the spawning season than larger, older fish. Batch fecundity estimates ranged from 0.26 to 2.83 million oocytes with a mean relative batch fecundity of 64.4 oocytes per gram of body weight. Predicted batch fecundity and potential annual fecundity increased with both length and age. This extensive set of reproductive parameter estimates provides many of the first quantitative estimates for this population and will substantially improve the quality of biological inputs to the stock assessment for South Pacific albacore.
| Item ID: | 31856 |
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| Item Type: | Article (Research - C1) |
| ISSN: | 1932-6203 |
| Additional Information: | © 2013 Farley et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
| Funders: | CSIRO Wealth from Oceans Flagship, Australian Fisheries Research and Development Corporation, 9th European Union Development Fund, Western and Central Pacific Fisheries Commission |
| Projects and Grants: | Australian Fisheries Research and Development Corporation Project #2009/012, 9th European Union Development Fund SCIFISH project |
| Date Deposited: | 13 May 2014 23:48 |
| FoR Codes: | 07 AGRICULTURAL AND VETERINARY SCIENCES > 0704 Fisheries Sciences > 070402 Aquatic Ecosystem Studies and Stock Assessment @ 100% |
| SEO Codes: | 83 ANIMAL PRODUCTION AND ANIMAL PRIMARY PRODUCTS > 8302 Fisheries - Wild Caught > 830207 Wild Caught Tuna @ 100% |
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