Survey of Seasonal Trematode Infections in Helisoma trivolvis (Gastropoda) from Lentic Ecosystems in New Jersey, U.S.A

Abstract

Helisoma trivolvis (Gastropoda) from 10 lentic ecosystems in New Jersey, U.S.A., was investigated on a seasonal basis from Fall 2003 to Fall 2004. A total of 6,766 H. trivolvis (5.7-22.9 mm shell diameter) was examined by isolation, and 8 different types of cercariae were recovered. Prevalence data from the 10 study sites showed cercariae of Echinostoma trivolvis from 9 sites (0.9–27.8%), cercariae of Zygocotyle lunata from 6 sites (0.1–7.7%), armatae cercariae from 4 sites (0.4–6.8%), brevifurcate apharyngeate cercariae from 4 sites (0.4–3.3%), longifurcate pharyngeate cercariae from 4 sites (0.002–3.6%), vivax cercariae from 2 sites (0.9–1.0%), brevifurcate pharyngeate cercariae from 1 site (0.6–1.1%), and gymnocephalous cercariae from 1 site (0.001%). The study showed that H. trivolvis is host to various different larval trematodes in New Jersey, and prevalence of digenean infections is affected by seasonality.