CONSUMPTION OF EGGS OF THE ENDANGERED FOUNTAIN DARTER (ETHEOSTOMA FONTICOLA) BY NATIVE AND NONNATIVE SNAILS

摘要

We examined the perecentage of consumption of eggs of the endangered fountain darter, Etheostoma fonticola, by native and nonnative snails from the San Marcos River, Hays County, Texas. Although all snails consumed eggs, non-native Marisa cornuarietis (Prosobrauchia: Ampullaridae) and native Helisoma anceps (Pulmonata: Planorbidae) consumed a significantly greater percentage of eggs than non-native Tarebia graniferea and Melanoides tuberculatus (Prosobranchia: Thiaridae) and the native Physella virgata (Pulmonata: Physidae). Dramatic increases in M. cornuarietis in the San Marcos and Comal springs may have an adverse affect on populations of fountain darters.