Abstract
The geographic distribution and abundance of five metazoan parasites differed between the blacknose dace, Rhinichthys atratulus, and the mummichog, Fundulus heteroclitus, and differed between sites in the Darby Creek, PA watershed. Parasitism appears to be negatively affected by urban development in that definitive (bird) hosts were less available for white grub (Posthodiplostomum minimum), black-spot (Uvulifer ambloplites), yellow grub (Clinostomum complanatum), acanthocephalans (Pomphorhynchus bulbocolli), and the nematode Eustrongylides sp. to complete their life cycles at one highly developed lower watershed site. High levels of parasitism were observed at two sites that are highly polluted and urbanized with eutrophic stream conditions, but near or within a wildlife refuge where there are abundant bird hosts. Therefore, a combination of issues appears to be increasing parasitism in the area. The parasites in the lower watershed are part of a complex aquatic community supported by the unique presence of the urban wildlife refuge.
