| Siamese Fighting Fish | ||||||||||||||
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| Scientific classification | ||||||||||||||
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| Binomial name | ||||||||||||||
| Betta splendens |
The Siamese Fighting Fish (Betta splendens) is currently regarded as a member of the Osphronemidae family of fish. It was previously placed in the family Anabantidae, and it possesses the labyrinth organ characteristic of that family. This is located just behind the head and it is a small chamber with many folds covered in tissue with many blood vessels that allow it to breath atmospheric air.
This is useful in the oxygen poor waters where it lives, and it is so dependant upon it that a Betta splendens will die if it cannot reach the water surface to breathe. The males build small bubble nests for their fry. The defend nest sites from other males extremely aggressively.
The natural coloration of B. splendens is a dull green and brown. However, in Asian countries they have long been used in a sport similar to cockfighting, and as a side effect they have been bred to have bright colours. Since the males readily engage in display responses which exhibit these colours, they are very attractive aquarium fish.
Both instinctive and learned behaviours of B. splendens have been studied in considerable detail. Its characteristic aggressive responses are readily elicited by its own reflection in a mirror placed outside an aquarium. The capacity to turn aggressive behaviour on and off in this way, without putting the subject at the risk of physical damage inherent in staging an actual aggressive conflict, made the fish a popular subject of study by ethologists and comparative psychologists interested in studying aggression. There was a stream of research on the fish's aggressive behaviour from the 1970s, though this has reduced lately, partly because of new approaches to studying aggression arising out of sociobiology, and partly because it was realised that, even if no tissue damage was done, repeatedly eliciting aggressive responses in the fish might be a source of stress. Interesting results were obtained, however; for example was shown that the presentation of such an aggression-eliciting stimulus will act as an unconditional stimulus in classical conditioning, and as a reinforcer in operant conditioning. It is as if the fish finds the opportunity to attack another fish rewarding.
See also