Helminths of Bullfrogs, Rana catesbeiana, Green frogs, R. clamitans, and Leopard Frogs, R. pipiens in New Brunswick

Abstract

Twenty-three species of helminths were identified from Bullfrogs (Rana catesbeiana) (n = 268), Green Frogs (R. clamitans) (n = 234) and Leopard Frogs (R. pipiens) (n = 280) collected at seven sites in New Brunswick. Twelve species were common to the three hosts while only three were restricted to a single host. Eighteen species are newly reported from New Brunswick. Of these, six species are also new for Canada. The Bullfrog, the more aquatic of the three hosts, harboured the greatest number of helminth species overall. Most of the helminths of New Brunswick Bullfrogs, Green Frogs, and Leopard Frogs have been recorded parasitizing a variety of amphibians and are widely distributed in North America. Encysted larval Echinostoma trivolvis was the most widely occurring helminth in all three frogs. Digeneans with complex life-cycles dependant on aquatic intermediate hosts predominate in terms of species diversity and abundance in Bullfrogs and Green Frogs. In the more terrestrial Leopard Frog, nematodes with direct life-cycle are the most abundant and widespread adult helminths infecting this host. Cestodes are relatively uncommon and acanthocephala are rare or accidental.