Depth
Hexanchus · Sharks & Rays

Bluntnose Sixgill Shark

Hexanchus griseus

0-2500m
Depth Range
4.8m
Max Size
Mediterranean
Distribution
0-2500m
Depth Range
4.8m
Max Size
Deep water
Habitat
Carnivore
Diet
Solitary
Social
NT
IUCN Status
Rare
Sighting Likelihood
Kingdom Animalia
Phylum Chordata
Class Elasmobranchii
Genus Hexanchus
Species griseus

Elasmobranch

Identification & Biology

  • IdentificationA massive, heavy-bodied shark with a broad, blunt snout and six gill slits on each side instead of the usual five. Small, fluorescent green eyes. A single dorsal fin set far back near the tail. Dark grey to brown body, sometimes with a lighter lateral line.
  • SizeCommonly 3 to 4 m. Maximum recorded length 4.8 m, possibly up to 5.5 m. Weight up to 590 kg.
  • Social HabitSolitary. A slow, powerful cruiser of deep water that occasionally rises to shallow depths at night to feed. One of the most primitive living shark species.
  • HabitatDeep continental and insular shelves and slopes. Comes into shallower water at night and in colder regions.
  • Depth0 to 2500 m. Typically found between 200 and 1100 m during the day. Night ascents to less than 30 m have been documented.
  • Feeds OnA wide range of prey including large bony fish, other sharks, rays, squid, crabs, and marine mammal carrion. An opportunistic apex predator.
  • DistributionWorldwide in tropical and temperate seas. Present throughout the Mediterranean, including deep waters around Malta.
  • DescriptionHexanchus griseus is a living relic, belonging to one of the oldest shark lineages on Earth. Its six gill slits (most sharks have five) are a primitive feature shared with fossil species dating back over 200 million years. In Malta, it inhabits the deep waters offshore and is occasionally caught by deep-water fishers. Listed as Near Threatened by the IUCN.

Range

Habitat & Distribution

Primarily a deep-water species found along continental and insular slopes throughout the Mediterranean. Adults typically inhabit depths beyond 200m during daylight, moving into shallower water at night to feed.

Where Malta divers have spotted this species

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Sightings are logged by divers using our What Did You See? dive-log tool. View the full live sightings map.

Detail

Preferred Environment

Favours deep benthic and benthopelagic zones near steep drop-offs and submarine canyons. Juveniles may be encountered in relatively shallow coastal waters, while adults remain in deep water during the day.

Encounter Tips

Best approached slowly and calmly. Avoid casting shadows directly over the animal. Neutral buoyancy and patience increase encounter success significantly.

Bluntnose Sixgill Shark species card

Biology

Behaviour & Diet

Feeding Strategy

A slow but powerful opportunistic predator that feeds on a wide range of prey including bony fish, other sharks, rays, squid, and crustaceans. Hunts primarily at night in shallower water.

Opportunistic predator

Reproduction

Ovoviviparous with large litters of up to 100 pups per brood. Gestation period is unknown but believed to be lengthy. Pups measure around 65-70cm at birth.

Ovoviviparous

Behaviour & Defence

Its large size and deep-water habitat provide natural protection. Generally docile and slow-moving, posing little threat to divers on the rare occasions they are encountered.

Size advantage

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Where to Encounter in Malta

Dive sites where Hexanchus griseus may be encountered will be added as sighting data is collected.

IUCN Red List Near Threatened

Conservation Status

This species is assessed as Near Threatened on the IUCN Red List. Mediterranean populations face ongoing pressure from fishing activity, habitat degradation, and climate-driven changes.

Source: IUCN Red List
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