![]() ![]() Since then, a range of different studies have followed, mostly focusing on visual discrimination abilities (for reviews see 1, 2, 6). In this study, sharks were successfully trained to acquire food by pressing a submerged bell, clearly showing that sharks are able to perform a simple cognitive task. One of the first studies looking at the ability of sharks to learn involved an operant conditioning regime 5. It is an important mechanism of adaptation to environmental unpredictability 3 and can increase an individual’s chances of maximizing its fitness 4. Learning is most simply defined as a change in behaviour as a result of experience 3. These abilities likely aid sharks in predator avoidance, social interactions, foraging and/or habitat selection 2. Examples of cognitive abilities are recognition, discrimination and social learning functions. Sharks have a wide range of cognitive abilities, which are comparable to teleosts and other vertebrates 1. New insights into shark sound recognition, detection and use are therefore of the utmost importance and will aid in management and conservation efforts of sharks. Currently, there is still a substantial lack of knowledge concerning the acoustic abilities and sound induced behaviours of sharks while anthropogenic noise is constantly on the rise. Within the tested range of 90–210 Hz, a frequency difference of 20–30 Hz is sufficient to discriminate the two sounds, which is comparable to results previously collected for sharks and teleosts. Transfer tests elucidated that, when both stimulus types were presented, both were used. ![]() Our results show that grey bamboo sharks can learn a Go/No-Go task using both visual and acoustic stimuli. After this, the smallest frequency difference leading to a change in behaviour in the sharks was studied using a series of transfer tests. This study explored the acoustic discrimination abilities of seven juvenile grey bamboo sharks ( Chiloscyllium griseum) using a Go/No-Go method, which so far had never been tested in sharks before. Some studies using acoustic stimuli in a cognitive context have been conducted, but a basic understanding of sound induced behavioural changes and the underlying mechanisms involved are still lacking. Most studies exploring elasmobranch cognitive abilities have used visual stimuli, assessing a wide range of discrimination tasks, memory retention and spatial learning abilities. Cognitive abilities of sharks are well developed and comparable to teleosts and other vertebrates. ![]()
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