Fish
Chimaera
Chimaeriformes · also called ghost shark, ratfish
Trailing a long, thin tail behind a smooth, ghostly body, a chimaera represents one of the oldest surviving branches of cartilaginous fish, having split away from the ancestors of modern sharks some 400 million years ago.
Overview
The chimaera, order Chimaeriformes, is a cartilaginous deep-sea fish native to temperate and tropical ocean waters worldwide, typically found along continental slopes. Its ancient evolutionary split from sharks, fused tooth plates, and venomous defensive spine make it one of the most distinctive surviving lineages of cartilaginous fish found anywhere in the deep ocean.
A shark relative unlike any shark
Despite sharing a cartilaginous skeleton with sharks and rays, the chimaera has diverged so far in appearance and biology over 400 million years that it barely resembles its distant relatives, trading rough skin and replaceable teeth for smooth flesh and crushing plates.
Status
Least Concern for most species, though detailed population data remains limited by the difficulty of surveying deep ocean habitat.
Chimaera: common questions
How long ago did chimaeras split from sharks?
This species belongs to a lineage that split from the ancestors of modern sharks approximately 400 million years ago, making it one of the oldest surviving branches of cartilaginous fish.
Why is the chimaera also called a ghost shark?
This species has smooth skin lacking the rough denticles of true sharks, along with a pale, ghostly appearance in some species, contributing to its alternative common name.
Does the chimaera have teeth like a shark?
No, this species has flattened, fused tooth plates rather than the rows of individual, replaceable teeth found in true sharks, an adaptation suited to crushing hard-shelled prey such as molluscs and crustaceans.
How does the chimaera defend itself?
This species has a venomous spine positioned in front of the dorsal fin, used defensively against potential predators approaching from above.