Production of Reproductively Limited Grass Carp for Biological Control of Aquatic Weeds

摘要

The need for a biological aquatic weed control is increasingly evident as the cost-effectiveness and environmental concerns make chemical treatment less desirable. The grass carp, a native fish of Southeast Asia is an effective consumer of aquatic macrophytes. However, potential adverse environmental impact must be considered when an exotic animal is proposed for introduction. Unwanted reproduction and subsequent naturalization is the greatest fear that biologists in the U.S. hold for grass carp. No reproduction would be possible if only a single sex were stocked but an efficient technique to monosex grass carp has not been available. This study applied experience gained with hormone sex reversing of tilapias and modified the method to suit specializations of grass carp. Functional sex reversal was the objective of the study but the ultimate goal was to use these fish as brood fish that would yield only single sex offspring. This approach depends on the stability of the sex determining mechanisms but if it is substantiated sufficient numbers of monosex fish can be inexpensively produced.