Awesome Animal Fact - Frilled Shark - A Living Fossil

Did you know the frilled shark has hardly changed (as a species) in 80 million years? Therefore, it is called a "living fossil."

This primitive shark, which is extremely rare, lives in deep water, usually 50–200 meters (160–660 ft) below the surface, and much deeper during warmer months of the year. They are long and eel-like, with characteristics of some of the most ancient fossilized sharks. They grow to about 6 feet (2 m) long and live about 25 years. Because they are rarely seen alive, little is known about their behavior.

They get the name frilled from the numerous tips of their gills that stick out beyond the edges of their gill covers.

Frilled sharks have about 300 teeth, arranged in clusters and pointing backward to help prevent their prey from escaping. They eat fish, squid, octopus, cuttlefish, and sea slugs (nudibranchs). Squid make up about 60% of their diet. This information is based on stomach contents and structural features observed in dead frilled sharks, because live frilled sharks have rarely been observed in the wild, and they are extremely difficult to keep alive in captivity.

No one knows how many frilled sharks remain, but because they are sometimes accidentally caught in fishing nets (resulting in their death), and because they reproduce very slowly, they have been classified as "near-threat of extinction."

Photo Credit:
Frilled shark - Citron / CC-BY-SA-3.0 via Wikimedia Commons