Evaluation of the influence of American eel (Anguilla rostrata) trophic interactions on Anguillicola crassus infection and new methods for stable isotope analysis of eels
University of New Brunswick
The American eel, Anguilla rostrata, is a culturally, commercially, and ecologically important species in eastern North American river systems. They are currently facing several threats, one of which is the parasitic nematode Anguillicola crassus. My research sought to improve understanding on how A. crassus is transmitted in a river system using stable isotope analysis, as well as improve methods for isotope analysis of both eels and A. crassus nematodes. I found that trophic position in conjunction with condition factor is associated with higher A. crassus infection intensity in yellow eels. Additionally, I discovered that δ 15N of A. crassus nematodes is significantly affected by the presence of host material in the digestive tract. I also devised a lipid estimation model for eel muscle tissue which can be used to lipid correct muscle samples, as well as demonstrated the viability of eel caudal fins as a nonlethal surrogate tissue for isotope analysis.