Effects of the Parasite Loxothylacus texanus on the Agonistic Behavior of the Crab Callinectes rathbunae

Abstract

This study presents the changes in the agonistic behavior of the crab Callinectes rathbunae parasitized by Loxothylacus texanus, collected in Alvarado Lagoon, Mexico. Alive parasitized crabs were observed in the laboratory for their behavior. Hepatopancreas of the parasitized crabs were fixed for examination. Both crabs with virgin and mature externa were monitored, and their degree of aggressiveness compared. The aggressiveness of the parasitized crabs decreases according to the parasite development. A possible relation with behavior and hepatopancreas infestation is given. In this study it is observed that the crabs with virgin externa are more aggressive than organisms with mature externa. Also, the agonistic behavior of the host decreases according to the development of the parasite. This is the first report where behavioral changes of parasitized crabs caused by a rhizocephalan, degree of development of the parasite and hepatopancreas atrophy are described.