by Chimaeras are cartilaginous fish in the order Chimaeriformes /kɪˈmɛrɪfɔːrmiːz/, known informally as ghost sharks, rat fish, spookfish, or rabbit fish.
At one time a "diverse and abundant" group (based on the fossil record), their closest living relatives are sharks and rays, though their last common ancestor with them lived nearly 400 million years ago.
Today, they are largely confined to deep water.
For defense, most chimaeras have a venomous spine in front of the dorsal fin. They use these fins to "fly" through water.
Source
At one time a "diverse and abundant" group (based on the fossil record), their closest living relatives are sharks and rays, though their last common ancestor with them lived nearly 400 million years ago.
Today, they are largely confined to deep water.
For defense, most chimaeras have a venomous spine in front of the dorsal fin. They use these fins to "fly" through water.
Source
