Effetto dei raggi X sul successo riproduttivo di Procambarus clarkii Girard.Effects of X ray irradiation on the reproductive potential of Procambarus clarkii Girard males.

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 other chemical treatments, and irradiation. This latter method seems to be the most feasible to control wild populations of crayfish, because it allows for the quick treatment of several individuals together and has a relatively low cost. On the other hand, the competitive ability of irradiated males might be affected and their survival decreased. The present study aims at analyzing the effects of a mild dose of X-ray irradiation on 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 with respect to the control males (n=40). These results, although preliminary, are encouraging in showing the potential that X-ray irradiation has to control the population size of invasive crayfish.