Goblin shark
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The goblin shark (Mitsukurina owstoni) is a rarely seen species of shark. It is notable for its long beak-like rostrum projecting forward of the jaws, its long, protruding jaws, and its pink color. When the jaws are retracted, the shark resembles a pink grey nurse shark (Carcharias taurus) with an unusually long nose. The goblin shark is the sole known living member of the family Mitsukurinidae; the relatively plentiful fossil record includes another two dozen or so species in two (extinct) genera, Scapanorhynchus and Anomotodon.
Distribution and habitat
Only about 45 specimens have been described in the scientific literature. They generally live at a depth of up to 1200 m, at the sea bottom. Half have been found off Japan, including the first one described (David Starr Jordan, 1898). TThey have been found in the western Atlantic off French Guiana; in the eastern Atlantic in the Bay of Biscay and off Madeira and Portugal; in the waters off South Africa, and in the western Pacific Ocean off Japan and Australia.
Anatomy and appearance
Goblin sharks lack a nictitating membrane. They have small dorsal fins, low and rounded. The anal fin is larger than dorsal fins, the pectoral fins are small, the pelvic fins are large, bigger than the dorsal fins. They ave no precaudal pit, and no keels.
The pink coloration, unique among sharks, is due to blood vessels underneath a semi-transparent skin, which bruises easily, thereby causing the coloring. The fins have a bluish appearance. As with thresher sharks and other members of the order Lamniformes, the upper lobe of the tail is much longer than the lower lobe.Typical specimens are 200–300 cm (6.6–9.8 ft) in the length; the largest seen so far was 385 cm (12.6 ft) in length. Several are preserved at the Australian Museum. The front teeth are long and smooth-edged, while the rear teeth are adapted for crushing.
Diet
Goblin sharks feed on deep-sea rockfish (Helicolenus dactylopterus, the jacopever, was found in one specimen), octopuses and crabs, most likely by sensing the presence of prey with electro-sensitive organs in the beak, suddenly protruding the jaws, creating a sucking motion with a tongue-like muscle, and using the teeth to hold onto the victim.References
- Duffy et al (2004). [Mitsukurina owstoni]. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Database entry includes justification for why this species is of least concern
- [Mitsukurina owstoni (TSN 159895)]. Integrated Taxonomic Information System. Accessed on 23 January 2006.
- "[Mitsukurina owstoni]." FishBase. Ed. Ranier Froese and Daniel Pauly. 10 2005 version. N.p.: FishBase, 2005.
External links
- [Elasmo Research page on goblin sharks]
- [Mikko's phylogeny page, listing fossil Mitsukurinidae]
- [Goblin shark in the Shark Database]
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