Influence of Temperature, Size and Sex on Aerial Respiration of Pomacea canaliculata (Gastropoda: Ampullariidae) from Southern Pampas, Argentina

Pomacea canaliculata (Lamarck 1822) is a freshwater snail belonging to the family Ampullariidae, whose natural distribution comprises most of the Plata river Basin and extends southwards to Tandilia and Ventania mountains in southern Pampas, Buenos Aires Province, Argentina (Martin et al., 2001). International concern about this voracious macrophytophagous snail rose when it, and other related species, became established as a serious pest of aquatic crops, including rice and taro, in South and East Asia (Cowie et al., 2006). In addition, the role of invading ampullariids as promoters of ecosystemic changes in invaded natural wetlands has been recently highlighted (Carlsson et al., 2004). Nowadays, P. canaliculata is listed among the top 100 worst invasive alien species of the world (Lowe et al., 2000), being the only freshwater snail included and probably the species with the greater potential for spread in North America (Rawlings et al., 2007). Ampullariids or apple snails have both a welldeveloped gill and a pulmonary sac or lung, and are commonly considered as “amphibious” snails (Andrews, 1965; Berthold, 1991). Water