Despite the utility of gastropod models for the study of evolutionary processes of great generality and importance, their effective population size has rarely been estimated in the field. Here, we report allele frequency variance at three allozyme-encoding loci monitored over 7 years in a population of the invasive freshwater pulmonate snail Physa acuta (Draparnaud 1805), estimating effective p...

We explored how functional diversity among predators of the freshwater snail Physa creates an adaptive trade-off for the snail’s shell morphology. Physid shells range continuously between elongate and rotund in overall shape. The protection conferred by alternative shell shapes depends on the mode of attack employed by predators. Predators attack Physa primarily through shell entry (by crayfish...

Overall 10389 snails were collected from four study areas of Punjab from November 2005 to October2006. The highest prevalence (38%) was found for Indoplanorbis followed by Physa (17%), Bellamaya(10.3%), Gyraulus (10%), Lymnaea (9.2%), Oncomelania (9%) and the lowest was found for Bulinus (6.7%).Only Indoplanorbis snails were found to be positive for Schistosoma bovis cercaria. Correlation betwe...