Helminth Parasites of Juvenile Brook Trout (Salvelinus fontinalis) from Four Maryland Creeks

摘要

A total of 126 juvenile brook trout, Salvelinus fontinalis, were collected in 2005 and 2006 from 4 Maryland creeks (Little Bear Creek, Blue Lick Run, Little Fishing Creek, and Puzzley Run) and examined for parasites. The trematode, Crepidostomum cooperi, and nematode, Cystidi-coloides ephemeridarum, were found in trout in all creeks. A cestode, Eubothrium salvelini, and another nematode, Rhabdochona cotti, infrequently infected Little Bear Creek trout. No other parasites were found. Prevalences and mean intensities of C. cooperi in trout from Little Bear Creek and Blue Lick Run (main study locations) were 96%, 68%, 20.5, and 7.2; and those values for C. ephemeridarum in Little Bear Creek and Blue Lick Run were 88%, 70%, 22.5, and 6.6, respectively. One-year-old trout had the same or higher prevalences and mean intensities of C. cooperi than young-of-the-year trout at both creeks. This was also true for C. ephemeridarum in trout from Little Bear Creek. The mean parasite species richness values in all examined trout for each location was Little Bear Creek (1.96), Blue Lick Run (1.38), Little Fishing Creek (2.0), and Puzzley Run (1.35). The low number of parasite species infecting juvenile trout in these Maryland creeks is similar to the low number of parasite species found in juvenile brook trout from Michigan creeks.