Two rare species of shark have surfaced off the coast of Japan in recent weeks.
In late January, a frilled shark was caught and in early February, a goblin shark was captured. Both species are rarely seen and were captured alive.
'The appearance of two of the strangest-looking sharks in the world within a short space of each other is very exciting,' says Patrick Campbell, fish expert at the Natural History Museum.
'They are not often found. We have only nine specimens of frilled shark in our collection and four goblin sharks dating back to 1903.'
Frilled sharks are sometimes caught in the nets of trawlers but are rarely seen alive. This 1.6 metre female specimen was seen by a Japanese fisherman who alerted the Awashima Marine Park in Shizuoka. They captured it and got video footage of the shark but it later died.
, usually live at ocean depths of between 600 and 1,300 metres and they are occasionally seen at the surface. They feed on small deep water fishes and squid.
Frilled sharks are odd-looking eel-like creatures. They have six gills that have frilly margins, giving them their name. Most sharks have only five gills.
A mouthful of sharp pitchfork-like teeth are in an odd arrangement, when compared with other shark species, having broad bases with three sharp cusps (the point of a tooth) separated by two small intermediate cusps.
The 1.3-metres-long goblin shark was caught as it swam in Tokyo Bay. It was transferred to an aquarium but later died.
Goblin sharks, Mitsukurina owstoni , are strange looking pink sharks with long pointed, dorsally flattened snouts. It is a bottom dweller living at depths of around 1,200 metres and probably feeds on small fishes and crustaceans.
The snout is thought to be an electrosensory device used to detect prey for capture. The jaws are specialised for rapid forward projection from the head on the detection of prey.
Early specimens were preserved with the jaw in the extended position leading to mis-representation in early books of its form. But it is now common knowledge that this is not how the goblin shark looks in life.
Although the goblin shark is thought to live throughout the world, very few specimens have ever been caught and only about 45 specimens have been documented.
Because of its widespread distribution, it is not classed as an endangered species, although like many other species of shark, it is often caught and killed in deep-sea fishing nets and trawlers.