Mechanical male sterilisation in invasive signal crayfish <i>Pacifastacus leniusculus</i>: persistence and functionality in captive and wild conditions

Management control methods for invasive crayfish remain of limited effectiveness, resulting in ongoing invasions high ecological impact. As management programmes integrating to limit juvenile recruitment could reduce population abundances, the efficacy a sterile male release technique (SMRT) based on manual removal gonopods was tested here captive and wild conditions by comparing survival, gonopod regeneration rates range reproductive metrics sterilised versus non-sterilised males. Sterilised survival high, with their removed regenerating at sizes that were always smaller than those In trials, while males showed significantly lower areas spermatophore cover non-sterilised, less accuracy placement, subsequent female brood size did not differ between two groups. The number females retaining clutches also these Over seven-year period wild, there no evidence suggesting SMRT reduced clutch retention rates. Although mechanical altered delivery gonopods, success unaffected. Several potential reasons this failure identified require further research.