National Anti-vivisection Society


National Antivisection Society

Differences between fish and humans


Fish are used for all kinds of research, with the largest number in ‘safety’ testing of products. One contract testing company uses fish in toxicity studies. The chemical is dissolved in the water in their tanks, and any lethal effects are noted after four days. Fish are commonly used to test environmental pollutants. Using ‘aversive conditioning’ (ie training by punishment), the goldfish were made to respond to colours or patterns. Vision research on goldfish has also involved cutting the optic nerve, removing the lens from the eye to blur the image on the retina, and studying the repair of vision under different forms of lighting.

What a Waste

  • There is a basic difference in metabolism, fish being cold-blooded and humans warm-blooded.
  • Fish hearts have two chambers, human hearts have four.
  • Nerves of the fish central nervous system can regenerate following injury but this is not possible with human nerves.
  • If a fish spinal cord is cut, the fish will be able to swim again within weeks; humans would be permanently paralysed.
  • Sharks do not get cancer.
  • Fish metabolise antibiotics differently from humans.
  • Fish cell membranes contain different fatty acids from those of humans.

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