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HON 499 Professor Moon's Library Instruction: KNJ


Article in Journal (InterLibrary Loan): Malacologia [Worldcat Catalog Search: "apple snail" AND memory]


Learned Predator Recognition in a Freshwater Snail, Pomacea canaliculata
  • Malacologia v52 n1 (01 2010): 21-29
Publication year:
  • 0076-2997
  • The involvement of associative learning in predator recognition has not been clear in aquatic invertebrates, including molluscs, due to confounding effects of sensitization. The freshwater apple snail, Pomacea canaliculata , displays an alarm response (crawling above the waterline) when exposed to crushed conspecifics or some predators. We conducted two series of experiments to investigate whether the apple snail learns to avoid predators. In the first experiment, hatchlings were conditioned simultaneously to crushed conspecifics and either a live carp, Cyprinus carpio , or a turtle, Chinemys reevesii , and subsequently exposed to the same predator without crushed conspecifics. Irrespective of the predator species used, the alarm response was significantly higher in conditioned snails than in unconditioned snails. Thus, the snail is able to avoid predators by learning, in a broad sense. In the second experiment, designed to distinguish associative learning from sensitization, we conditioned hatchlings to crushed conspecifics and either a carp or a turtle. The hatchlings were subsequently exposed to one or other of the predators. Hatchlings that were conditioned to a predator displayed significantly higher alarm response when later exposed to the same predator than another predator, suggesting that the snail can recognize predators by associative learning.

Article in Journal (via InterLibrary Loan) : Behavioural Processes {Science Direct database: "apple snail" AND "learned behavior" AND pomacea)



Releaser-induced recognition learning by gastropod molluscs



The releaser-induced recognition learning model (Suboski, 1990) is briefly introduced and examined in the context of a review of the extensive literature on learning by gastropod molluscs. Substantial involvement of learning processes were found to occur in the acquisition of food and environmental hazard recognition. These findings are consistent with a learning model in which releasing stimuli activate a stimulus-substitution mechanism that induces recognition of otherwise biologically inert stimuli. According to this model, simple recognition learning by molluscs basically consists of the stimulus redirection of innately-organized released responses. A releasing stimulus activates transfer of control over release of responses from the releasing stimulus to an initially-neutral stimulus, typically a temporal predictor of the releasing stimulus. The model offers a simple, parsimonious, and comprehensive account of molluscan learning that integrates Pavlovian and at least simple instrumental conditioning as well as providing a potential explanatory mechanism if intriguing indicators of social communication of food recognition by gastropods were to be substantiated.