Meeting Abstract

S7.1-1  Monday, Jan. 6 08:00  Euhaplorchis californiensis, a brain-infecting trematode parasite, is associated with changes in physiology and behavior in its killifish second intermediate host WEINERSMITH, K.L.*; HANNINEN, A.F.; SIH, A.; EARLEY, R.L.; University of California Davis; University of Virginia; University of California Davis; University of Alabama

The trematode parasites Euhaplorchis californiensis (EUHA) and Renicola buchanani (RENB) infect California killifish (Fundulus parvipinnis) as second intermediate host. Infected killifish exhibit conspicuous behaviors, and infection is associated with a 10-30 times increase in predation rates by birds, the parasites’ shared definitive host. EUHA is also associated with changes in neurotransmitter activity, which could result in downstream changes in steroid hormone release rates. In this study we explore associations between stress hormones (cortisol) and sex hormones (11-ketotestosterone and estradiol) and EUHA and RENB density in wild-caught California killifish. We find that the interaction between duration of handling stress and the density of EUHA influences release rates of cortisol and 11-ketotestosterone. We discuss the implications of these findings, and plans to further explore these relationships using controlled infections.