(By Albert Charles Lewis Gotthilf Guenther; John Graham Kerr (Encyclopædia Britannica, 11th ed., Vol. 24, p. 809) [Public domain], via Wikimedia Commons )
The Frilled Shark is one of the weirdest sharks in the world. It's one of the few sharks with a body in the shape of an Eel and a unique formed head, which no other shark or fish has. The Frilled Shark is one of the most primitive shark species that is still alive. It hasn't evolved for thousands of years and the reason for this is still unknown.
We have to make a difference between two kinds of frilled sharks. At one part of the world we have the Hexanchiformes frilled shark and at the other side we have the Southern African frilled shark, which only lives in the regions of South-Africa.
Frilled Sharks or Chlamydoselachus anguineus have a dark brown coloured skin with six gill slits, which makes them a shark and not an eel. They have little sharp teeth and with the information that the researchers possess they think that this shark can reach a size of about 2 meters. The Frilled Shark has also a very asymmetric tail fin and two big fins close to his head.
(By OpenCage (http://opencage.info/pics.e/large_13408.asp) [CC-BY-SA-2.5 (http://creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons)
Habitat & Eating Behaviour
Frilled sharks appear almost everywhere, but are mostly reported in South-Africa, Norway, New Zealand and some other countries. They live on shallow depths of around 50 meters to depths of even 1500 meters. Their diet mainly exist out of squids, several little species of sharks and other little deep sea fishes. Remember this is a living fossil and it's the only specie in his order who survived evolution.
The reproduction of the Frilled Shark happens oviparous (eggs hatch in the body of the mother and emerge as young Frilled Sharks), the eggs of the Frilled Sharks hatch after around one to two years. There isn't a lot of information available about the Frilled Shark, because the encounter with humans is extremely rare.