Behaviour 2019
The Effects of Symbiote Ostracods on Invasive Crayfish Behaviour 
Audrey N Fontes 1, Gary M Bucciarelli2, Lee B Kats 1. 1Pepperdine University , Malibu , California , United States; 2University of California, Los Angeles, Los Angeles, California, United States

Invasive crayfish, Procambarus clarkii, are known to negatively impact the biodiversity of Santa Monica Mountain streams. Small symbiotes, ostracods, live on Procambarus clarkii in some local streams. However, their effect on the behaviour of invasive crayfish is unknown. We used an aqueous chlorobutanol solution to remove ostracods from crayfish. We paired control crayfish with those that had ostracods removed and scored aggressive interactions. Crayfish without ostracods were found to be significantly more aggressive towards crayfish with ostracods. When we compared feeding behaviour, we found that crayfish without ostracods consumed food more quickly than control crayfish. We again subjected crayfish to the ostracod removal process and confirmed that there were significantly fewer ostracods on the crayfish that had gone through the initial ostracod removal procedure. Given that the presence of ostracods seems to have moderated both aggressive and feeding behavior, we suggest that symbiote ostracods help reduce impacts of invasive crayfish on local streams.