Food and Feeding in Pomacea canaliculata (Gastropoda: Ampullariidae)
ALEJANDRA L. ESTEBENET
Departamento de Biologia y Bioquimica, Universidad Nacional del Sur, San Juan 670-8000 Bahia Blanca, Argentina
Food preferences, growth rates on different aquatic plant diets, and the ability to detect distant food sources were studied in the ampullariid snail Pomacea canaliculata. The snails actively select their food. No ontogenetic differences were detected in feeding preferences. The most preferred macrophyte was Zannichellia palustris, followed by Myriophyllum elatinoides, and Chara contraria. The snails showed a low preference for Rorippa nasturtium-aquaticum and Potamogeton striatus, whereas Elodea canadensis was not selected. The growth experiments reflected this behavior; snails reared on Zannichellia reached the largest sizes, followed by those fed on Myriophyllum. No statistical differences were detected in the size of snails reared on Rorippa and Potamogeton. The results obtained in distant chemoreception experiments support the hypothesis that P. canaliculata is able to detect chemical signals from some distance. This ability remains unaffected whether the stimulus source was positioned on the left- or on the right-hand side of the Y-chamber.
The Veliger 38(4): 277-283 (October 2, 1995)