FishFish are cold blooded, live in water and
are covered in scales. They breathe through gills located on the sides
of their heads. Their gills take oxygen out of the water around them so
they can breathe. Their limbs, if they have any, are in the shape of
fins and do not have digits. They exhibit greater species diversity than
any other group of vertebrates, with over 32,000 known species.Fish
live in oceans and freshwater ecosystems. Well adapted to their water
world, fish secrete a special type of mucus from their skin. The slime
coating helps them move through water faster, protects them against
parasites and diseases and covers wounds to prevent infection.
Fish orient themselves using landmarks and mental maps based on multiple landmarks or symbols. They possess spatial memory and visual discrimination.