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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #356376
Title: Effect of pond-or strip-spawning on growth and carcas yield of channel catfish (Ictalurus punctatus) progeny

Author
item Bosworth, Brian
item Waldbieser, Geoffrey - Geoff
item GARCIA, ANDRE - University Of Georgia
item LOURENCO, DANIELA - University Of Georgia

Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/7/2019
Publication Date: 10/7/2019
Citation: Bosworth, B.G., Waldbieser, G.C., Garcia, A., Lourenco, D. 2019. Effect of pond-or strip-spawning on growth and carcas yield of channel catfish (Ictalurus punctatus) progeny. Aquaculture. 51:407-417.

Interpretive Summary: Genetic selection to improve important traits has played a critical role in improving production efficiency in most crop and livestock species. Researchers at the Warmwater Aquaculture Research Unit, USDA-ARS, are using genetic selection to improve growth rate and carcass yield (the amount of edible meat) in channel catfish with the goal of releasing improved catfish to U.S. farmers. Genetic selection works by choosing parents that have higher genetic merit for important traits, which means they possess genes for superior performance, and these genes and the associated superior performance are passed on to their offspring. Genetic merit is estimated by a statistical process which measures the similarity among the phenotypic performance (the physical measurement for a trait) of an animal and the phenotypes of related individuals in the population. Adjusting phenotypes for non-genetic factors that influence them is critical to obtaining accurate genetic merit estimates. Catfish can be produced by either voluntary spawning in ponds (pond-spawning) or use of natural hormones to induce ovulation and manual collection of eggs (strip-spawning). Researchers compared effects of spawning-type (pond-spawning vs. strip-spawning) on offspring performance to determine if spawning-type needed to be accounted for in genetic merit estimations. The results showed that catfish offspring produced by strip-spawning had considerably lower growth rates and carcass yield than catfish produced by pond-spawning; and therefore, the spawning method used to produced catfish needs to be accounted for in genetic merit estimation. The results will lead to more accurate estimation of genetic merit for important traits of catfish, which will result in more accurate and efficient development of genetically improved catfish for use by U.S. catfish farmers and processors.

Technical Abstract: Phenotypic performance of progeny is used to estimate genetic variance, breeding values and response to selection in fish breeding programs, and accounting for environmental effects on phenotypes is an important aspect of accurate genetic analysis. Catfish progeny can be produced either by natural pond-spawning, where fish spawn voluntarily in ponds; or by hormone induced strip-spawning. We examined the effects of spawning-type (pond-spawning vs. strip-spawning) on fingerling weight, harvest weight and carcass yield of channel catfish progeny. Progeny from 65 pond-spawned full-sib families and 29 strip-spawned full-sib families were reared in separate family tanks, then tagged as fingerlings and stocked communally in replicated earthen ponds, and harvested at 16 to 18 months post-hatch. A sample of fish from each full-sib family was measured for carcass yield. Fingerling weight was not affected by sex or spawning-type. Harvest weight was higher for males than for females and higher for pond-spawned fish than for strip-spawned fish. Carcass yield was higher for females than for males and higher for pond spawned fish than for strip spawned fish. Results indicate strip-spawning had substantial negative effects on harvest weight and carcass yield of progeny. Other factors such as rearing environment (feed and water quality) and genetic composition of broodfish, age of progeny etc. were similar for strip-spawned and pond-spawned progeny. Accounting for the effect of strip-spawning in breeding programs and reducing the negative effect of strip-spawning in commercial production is important.