They are fearsome predators that grow up to 3m long and feed on small fish and shrimps. Coelacanths are often described as living fossils, and were once thought to have been extinct for 70 million years. Fossils of lungfish like them date back nearly 400 million years. Lampreys and hagfish The first animals with backbones were fish with neither jaws nor scales. Fish like these first appeared over 450 million years ago.
Lampreys are long, thin fish that live in the sea, but swim up rivers to lay their eggs.
They are parasites, latching on to other fish with a ring of horny teeth. A lamprey's mouth is like a sanding disc with sharp teeth that it uses to rasp into its victim's skin to suck its blood. Parrot fish have a sharp 'beak' for grazing on coral. The warm waters of the tropics are rich in fish life, especially in shallows around coral reefs. Beautiful, brilliantly coloured fish like angelfish and butterfly fish teem among the coral reefs of the Indian and Pacific oceans and the Caribbean.