Each vertebrate group has characteristics which help to identify its members. Characteristics of Fish Fish have backbones. Fish are cold-blooded. Fish breathe with gills. Fish lay eggs.
Fish have scales.
Fish have fins. Characteristics of Amphibians Amphibians have backbones. Amphibians are cold-blooded. Amphibians first breathe with gills, and then they breathe with lungs. They go through metamorphosis.