This very primitive fish has the form of an eel. Its skin is smooth and without scales. Its dorsal, caudal, and anal fins are interwoven; it has no other fins. Its skeleton is cartilaginous like a shark's, and this makes it very flexible. These fish can reach 60 to 70 cm in length.Their mouth has no jaws and is surrounded by six to eight short tentacles, called barbels. Their eggs are heavy, large, and few in number. Hagfish are a marine fish and often live on or near the muddy ocean bottom. One species is found on the Atlantic coast; two on the Pacific. When they feel disturbed or threatened, hagfish produce a great quantity of mucus as a protective device. They are scavengers, that is, they feed mostly on dead or dying animals. Commercial fishermen dislike them because they eat the fish caught in fishing nets.