Distribution, prevalence and intensity of Anguillicoloides crassus in the American eel, Anguilla rostrata , in the Bras d’Or Lakes, Nova Scotia

摘要

In 2009 to 2010, 169 American eels, Anguilla rostrata, from the Bras d’Or Lakes, Nova Scotia, were examined for presence of the invasivenematode Anguillicoloides crassus. Prevalence and intensity in eels were determined to be higher than previously reported for the Bras d’OrLakes. Overall prevalence was determined to be 46% with mean intensity at 9 parasites/eel (±11). Higher prevalence of A. crassus (60 to67%), higher mean intensities (6.8–12.6 parasites/eel), and greater number of eels with more than 20 parasites per eel were found in semienclosedbasins with higher freshwater input and close proximity (13 to 20 km) to probable source(s). No significant differences were foundbetween mean intensity between riverine, estuarine or coastal lagoon habitats, however, prevalence was found to be higher in riverinehabitats. No significant differences were found between infected and non-infected eels for total length, total body weight, gonad weight, GSIor condition factor. The Bras d’Or Lakes form a semi-enclosed estuarine body with low flushing times, high summer water temperatures(>20°C) and an international shipping destination, that makes it an ideal environment for the establishment and spread of A. crassus. Theneed to preserve aquatic habitats and reduce environmental stressors is imperative in an A. crassus infected environment. Greater controlsand innovative solutions are needed to prevent further introduction of aquatic invasive species.