The effects of X-ray irradiation on male reproductive potential in the invasive crayfish, Procambarus clarkii: preliminary results.

Since the 1950s, the Sterile Male Release Technique (SMRT) has been successfully used to control populations of nuisance insects. In some invasive aquatic species, male sterility has been attained by the use of genetic manipulation (ploidy and lethal genes), hormone and or chemical treatments, and irradiation. This latter method seems to be the most feasible to control wild populations of crayfish, since it allows for the quick treatment of several individuals together at relatively low cost. On the other hand, sexual attractiveness or competitive ability of irradiated males could be affected and their survival decreased. The present study analyzes whether a mild dose of X-ray irradiation might affect the reproductive potential of the invasive crayfish Procambarus clarkii. We found that a treatment of 20 Gy X-rays did not alter the survival and the behavior of sexually competent males (n = 40), but affected their reproductive success by significantly reducing (by 43 %) the total number of offspring in comparison with non-treated males (n = 40). These results, although preliminary, are encouraging in showing the potential of X-ray irradiation for controlling population sizes of invasive crayfish.