Fish
Interaction
The fish have protective scales
They are ectothermic (the body temperature depends on the environment)
The fish dectect the presence of others living things through the vibration of the water.
Nutrition
Most fish are carnivores: some are predators and others are scavengers (eat dead animals) Also there are some herbivores omnivores.
Reproduction
Fish are sexual (two parents and the offsprings are not identical). Most are oviparous and lay eggs without an impermeable shell, like frogs.
Bony fish
They have a bone skeleton, the gills are protected by the operculum. And they have and homocercal tail fin (a tail divided into two equal parts. These fish have flat, round scale and a swim bladder.
Cartilaginous fish
Have a skeleton of cartilage, they don't have an operculum to protect the gills. They have an heterocercal tail fin (tail divided into two parts of different sizes) No swim bladder.
