Researchers at Cranfield University have found that small spotted catsharks
Cognitive ability is important for animals inhabiting changing environments such as the oceans - it facilitates memory and learning which improves the ability of an animal to catch prey or search for mates. Whilst marine mammals have been shows to possess cognitive ability, less is known about the capacity of sharks for learning and memory.
To assess the cognitive ability of the small spotted catshark, the researchers focused on the electroreception sense of the shark. Electroreception is an important sensory tool for sharks and rays; it allows them to detect natural electric fields such as those which might be given off by prey items. An assessment of the ability of sharks and rays to distinguish between electric stimuli given off by prey and that of an artificial object - such as undersea electric cables - will be valuable when assessing the impact these artificial electric stimuli may have on marine fauna.
The researchers split the sharks into 4 groups - those which would undergo positive reinforcement and would receive a food reward upon showing interest in an electrical stimulus and those which would not. After each group had participated in the experiment, the groups were switched so that the ones who previously received positive reinforcement no longer would and vice versa.
The researchers found that sharks conditioned to receive a food reward upon investigation of the electric stimulus were far more likely to return and bite the probe than those which had not received any reward, demonstrating rapid learning ability of this species. However when examining the ability of the sharks to retain this information as memory, the researchers found that the sharks possessed a memory of 12 hours to 3 weeks. The small spotted catfish inhabits mainly coastal waters which are highly variable and a memory of longer than 3 weeks may not be a survival requirement of this species. Therefore investigation into other, preferably pelagic shark species, may yield different results and potentially a longer memory time.
Kimber, J., Sims, D, Belamy, P. and Gill, A. (2014) Elasmobranch cognitive ability: using electroreceptive foraging behaviour to demonstrate learning, habituation and memory in a benthic shark. Animal Cognition. 17(1): 55-65
Cognitive ability is important for animals inhabiting changing environments such as the oceans - it facilitates memory and learning which improves the ability of an animal to catch prey or search for mates. Whilst marine mammals have been shows to possess cognitive ability, less is known about the capacity of sharks for learning and memory.
To assess the cognitive ability of the small spotted catshark, the researchers focused on the electroreception sense of the shark. Electroreception is an important sensory tool for sharks and rays; it allows them to detect natural electric fields such as those which might be given off by prey items. An assessment of the ability of sharks and rays to distinguish between electric stimuli given off by prey and that of an artificial object - such as undersea electric cables - will be valuable when assessing the impact these artificial electric stimuli may have on marine fauna.
The researchers split the sharks into 4 groups - those which would undergo positive reinforcement and would receive a food reward upon showing interest in an electrical stimulus and those which would not. After each group had participated in the experiment, the groups were switched so that the ones who previously received positive reinforcement no longer would and vice versa.
The researchers found that sharks conditioned to receive a food reward upon investigation of the electric stimulus were far more likely to return and bite the probe than those which had not received any reward, demonstrating rapid learning ability of this species. However when examining the ability of the sharks to retain this information as memory, the researchers found that the sharks possessed a memory of 12 hours to 3 weeks. The small spotted catfish inhabits mainly coastal waters which are highly variable and a memory of longer than 3 weeks may not be a survival requirement of this species. Therefore investigation into other, preferably pelagic shark species, may yield different results and potentially a longer memory time.
Kimber, J., Sims, D, Belamy, P. and Gill, A. (2014) Elasmobranch cognitive ability: using electroreceptive foraging behaviour to demonstrate learning, habituation and memory in a benthic shark. Animal Cognition. 17(1): 55-65
