To celebrate Halloween, we’re bringing you some ghostly critters from the deep!
Ghostshark and ratfish are common names used for a chimaera, a group of unusual fishes which, despite the common name, isn’t really a shark at all! Their skeletons are made of cartilage, not bone.
The males have prominent reproductive features called claspers, and the females lay eggs in leathery cases. These characteristics make sharks and rays their closest living relatives, but about 400 million years ago they branched off the evolutionary tree from those groups, remaining isolated ever since.
Most species have a venomous spine in front of their dorsal fin. One of the oldest and yet least known groups of fishes alive today, ghost sharks are deep-dwelling and rarely seen alive. They can be found at depths to 2,600 meters (8,500 feet).