Action: Procambarus crayfish control: Sterilization of males
Key messagesRead our guidance on Key messages before continuing
- One replicated laboratory study in Italy found that exposing male red swamp crayfish to X-rays reduced the number of offspring they produced by 43%.
Sterilisation of males which are allowed to remain in wild populations can help to reduce the rate of population increase. For example, a review study from the UK (Stebbing et al. 2012) reported that removal of pleopods used by males to deposit spermatophores onto the females led to a population decrease over a three year period.
Stebbing P.D., Longshaw M., Taylor N., Norman R., Lintott R., Pearce F. & Scott A. (2012) Review of methods for the control of invasive crayfish in Great Britain. CEFAS. Contract C5471 final report. pp 105.
Supporting evidence from individual studies
A replicated laboratory study conducted between 2005 and 2006 in Italy (Aquiloni et al. 2009) found that male red swamp crayfish Procambarus clarkii, exposed to X-rays had a reduced reproductive ability. The number of offspring they successfully produced was reduced by 43% compared to a control group (no x-ray exposure). X-ray exposure did not affect the males’ survival and mating abilities. Irradiated males had smaller testes and altered sperm production that lasted for at least a year. A total of 122 males were tested, half in a control group with no irradiation. Male crayfish were placed individually inside a plastic tube and exposed to a 6 MeV electron beam for five minutes. Testes and sperm production were measured, as were the number of viable offspring produced post-mating.