Host diet and parasitic helminth infections within native, established and introduced fish of Algonquin Park

Freshwater fish biodiversity loss has been attributed to many reasons, including invasive species infectious diseases. I examined 112 invasive Rock Bass (Ambloplites rupestris), 59 established Smallmouth Bass (Micropterus dolomieu), and 60 native Pumpkinseed sunfish (Lepomis gibbosus) from 8 different lakes in Algonquin Park, ON, Canada to evaluate their endohelminth parasites. My results indicate that established and native fish are not only more likely to be infected with trophically-transmitted parasites such as cestodes (tapeworms) and acanthocephalans (thorny-headed worms) than invasive Rock Bass, but they also have a higher infection intensity and greater diversity of endohelminths. There was also a significant difference between the three fish species with respect to non-trophically transmitted larval trematodes (flatworms), which reflect the habitat of fish. Along with host size, I examined fish diet and habitat use to demonstrate how the ecology of different species influences their probability of infection, parasite communities, and possible ease of establishment in novel environments.