Decline in conspecific aggression of invasive Procambarus clarkii as a result of swimmeret and androgenic gland removal

The Louisiana red swamp crayfish, Procambarus clarkii, is an invasive species that inhabits the Santa Monica mountains. The species which is native to Louisiana, Texas, and Mexico, has been detected in the streams of the Santa Monica mountains since the 1960s. Since then, the stream ecosystem and biodiversity of Southern California has been threatened due to the fact that these red swamp crayfish have no native predators to keep populations of these invasive species at a sustainable level. P. clarkii are also extremely aggressive and will consume almost all living organisms they encounter thus compounding their negative impact on biodiversity and local ecosystems. This aggression is more prevalent in males than females because the male red swamp crayfish have androgenic glands which are housed in their swimmerets. The androgenic gland contains androgenswhich control “the so-called masculinization of the body” which includes growth, development of the body in male proportions, and aggressive behaviors. The data showed a trend in a decrease of aggression as a response to the removal of swimmerets, however these data were not significant