Channeled applesnail (Pomacea canaliculata-complex) population dynamics, current distribution and reproductive potential on the Texas Gulf Coast.

摘要

The exotic invasive channeled applesnail (Pomacea canaliculata ) has been a severe pest for agricultural crops and native macrophytes in many countries throughout the world, especially in Southeast Asia. Pomacea canaliculata-complex snails are present in the United States in Texas and six other continental states. Pomacea canaliculata occurs in Hawaii. The first reproducing population of P. canaliculata-complex snails in Texas was found in the "Rice Belt" region of the Gulf Coast in 1989. Others were confirmed in 2000. Because of their location in this sensitive region, there exists a high potential for damage to rice crops and possibly to native wetlands vegetation. Studies were conducted in several lentic and lotic ecosystems in Southeast Texas for a one-year period, including: applesnail population dynamics (changes in size structure, densities and biomass). Average snail densities varied greatly among sampling sites, with a maximum recorded density of 44 snails/m2 and biomass of 3.024 kg/m 2 found in lentic systems. 314 sites on the Upper Texas Gulf Coast were surveyed for presence of snails during the summer of 2005; 44 of these sites were found to have reproducing snail populations. Snails were found in 17 waterways and their tributaries, including the American Canal, Buffalo Bayou, Oyster Creek, Armand Bayou, Dickinson Bayou, Mustang Bayou, New Bayou, Bear Creek and Clear Creek. Densities of snails were studied in selected survey locations. Data of abiotic and biotic parameters of sampled sites were collected and were used to assess limiting factors and current distribution.