Vertebrates are animals with a spine or vertebral column. All vertebrates are build according to a general body plan where the mouth is found at the anterior end of the animal and the anus is positioned before the end of the body. The end of the spine is often shaped into a tale.
Of the approximately 58000 species of vertebrates, only All marine vertebrates are members of one of the following three superclasses:
- Agnatha is a superclass of jawless fish.
- Pisces includes fish with a jaw like ray-finned fish (class Actinopterygii), sharks and rays (class Elasmobranchii) and other cartilaginous fish (class Holocephali).
- Other vertebrates like amphibians, reptiles, birds and mammals are all members of the superclass Tetrapoda.