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Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only Publication Acceptance Date: 7/20/2011 Publication Date: 8/2/2011 Citation: Weber, G.M. 2011. Use of technologies to control reproduction in finfish aquaculture. Society for the Study of Reproduction Annual Meeting. Paper No. 101-200. Interpretive Summary: Technical Abstract: The proportion of food fish derived from aquaculture has increased dramatically over the past several decades and currently accounts for nearly 50% of the world's consumption. Since production from capture fisheries has stagnated, increased supplies of food fish will need to come from aquaculture. Controlling reproduction is central to increasing aquaculture capacity and efficiency. Controlling reproduction of fishes is in its infancy, with the lifecycle of most cultured species having been closed in captivity only within the last few decades. The phylogenetic diversity of fish is far greater than that of all other vertebrates combined, and as a result the diversity of modes of reproduction and reproductive strategies in food fish species are astounding. As such, the reproductive technologies used to optimize reproduction related events and attributes among these species is also diverse. A first step for food fish industries as with other forms of agriculture is development of a reliable supply of seedstock. As a start, technologies have been developed for assessing sex and reproductive condition, and inducing spawning. In most ways cultured fish are very similar if not identical to their wild counterparts. For some species broodstock are still captured from the wild, or are only a few generations removed. The extent to which reproductive development is disrupted in captivity often changes with early generations of domestication, resulting in continuous revision of reproductive control protocols, often with decreasing dependence on exogenous hormones. Technologies involving environmental manipulations or hormone therapies are also employed to induce fish to spawn at times of the year when they usually don't. Sexually dimorphic growth is common in fish so often means of controlling the sex of the animals is critical for efficient production. In addition, gonads can be very large in many species, over 20% of body weight in salmonids, negatively impacting growth rates, feed conversion efficiencies, and flesh quality. In such cases sterilization procedures, or sex control in those where one sex matures earlier than the other, are practiced. The extent and means of controlling reproduction even within a species is dependent on many factors. Often practices change as industries mature. As an example, greater control is required for a selective breeding program than simple seedstock production. In addition, societal preferences such as those regarding the use of hormones or transgenics impact the technologies that might be applied to control reproduction. Most important is access of technologies to the farmer, as aquaculture is practiced throughout the developed and developing world. In summary, aquaculture of food fish is greatly expanding and increasing in diversity, as are technologies to control reproduction of the many species being grown. |
