Removal and transfer of symbiotic ostracods and the impact of feeding behavior and conspecific aggression in host crayfish, Procambarus clarkii

The invasive crayfish, Procambarus clarkii, is one of the species responsible for causing major changes to the Santa Monica Mountain streams. Small symbiotes, ostracods, live on Procambarus clarkii. Their effect on the invasive crayfish is unknown. An understanding of the effect of ostracods on the crayfish feeding and aggression behavior would provide information on what makes the crayfish such an effective invader. An aqueous 0.5% chlorobutanol solution was developed to allow for the removal of ostracods from crayfish without killing the ostracods or crayfish. Crayfish with ostracods and crayfish that have had ostracods removed with this treatment were studied. There were statistically significant fewer ostracods on the crayfish that had gone through the ostracod removal procedure. Also, crayfish without ostracods were found to be statistically significantly more aggressive towards crayfish with ostracods. In regard to feeding, the results show that presence of ostracods significantly affected whether crayfish consumed food. When ostracods were present, these crayfish were less likely to consume prey, whereas all crayfish without ostracods consumed prey