Urban ponds as a potential risk in the transmission of parasites

Abstract

We studied freshwater snails inhabiting an urban pond in an enclosed private community from the northern Province of Buenos Aires, Argentina for a year and monitored individuals in order to observe parasite emergence. Specimens of the predominant snail species were measured and analyzed histologically to examine possible larval effects on the gonadal tissue causing alterations in the developmental stages of the gonads and the degree of parasite prevalence per age, sex, and host size calculated. Four species of snails were registered: Pomacea canaliculata, Physa acuta, Biomphalaria peregrina and Heleobia parchappii. The last of these was the most abundant, whose breeding season was in the spring. The parasitized snails exhibited a greater average length than those free of parasites. The larval prevalence increased with host length, becoming the highest in post-reproductive stage, but was not different between the sexes. Among the emerged cercariae, we noted a marked predominance of the family Notocotylidae.