The Greenland shark (Somniosus microcephalus), also called the northern shark, is a shark belonging to the genus Somniosus, a group made up of several species known as sleeper sharks. This animal, despite its name, also inhabits other marine areas other than the Kingdom of Denmark. Currently, there are several backup plans to conserve this species due to its declining population. In addition, this animal has a very particular characteristic, since it is one of the vertebrates with the longest life span that exists on earth.Discover all the endangered sharks!
Keep reading this AnimalPlanet page and find out what the lifespan of the Greenland shark is, as well as many of its absolutely incredible characteristics!
Origin
- America
- Europe
- Germany
- Canada
- Cuba
- Denmark
- Spain
- United States
- Faroe Islands
- France
- Greenland
- Ireland
- Iceland
- Norway
- Portugal
- United Kingdom
- Russia
- Saint Pierre and Miquelon
Characteristic of the Greenland shark
The Greenland shark is a large shark that can measure about 6 meters in length, and it has the particularity of only growing about one centimeter per year.Although heavier specimens have been seen before, it weighs about a ton. It may be of a light gray or brown tint, possibly it could present stripes or stains which vary in intensity on the background color. As for his skin, it is quite rough due to the presence of dermal denticles.
The Greenland shark is robust, cylindrical in shape; its muzzle is short and has a rounded tip. Its two jaws have several rows of teeth, but they are of different shapes. The upper ones are sharp, while the lower ones have a cutting function. The precaudal fins are small. On the other hand, the dorsals are symmetrical and although the caudal is present, this shark does not have an anal fin.
How many years can the Greenland shark live? The particularity of this shark is its longevity. According to a recently published study, the life expectancy is 272 years for this species.However, one of the studied specimens was 392 ± 120 years old, which allowed us to conclude that the Greenland shark is the vertebrate with the longest lifespan within animal biodiversity. Some researchers claim to be more conservative in this regard, opting for an average longevity of around 150 years. However, there is no doubt that it is an animal with a very high life expectancy.
On the other hand, this shark develops partial blindness due to its parasitic relationship with a species of copepod, which feeds on corneal tissue and causes it to go blind. But sharks have several sensory mechanisms to navigate the oceans.
Greenland Shark Habitat
The habitat of this species is located in the maritime ecosystems of the North Atlantic, the United States, Canada and Greenland. Also from Portugal to an area of the Arctic Ocean and the East Siberian Sea. Its depth range varies from the surface down to about 2,600 meters.However, in some areas it prefers to live between 300 and 500 m deep.
The water temperatures in which the Greenland shark is usually found are between 1 and 12° C in coastal ecosystems, pelagic and demersal zones. It also moves to intertidal areas and estuaries. It is undoubtedly a species that moves in northern polar ecosystems.
Habits of the Greenland Shark
The Greenland shark usually swims quite slowly. It has a solitary behavior, except during mating or informal encounters that occur in areas where food is concentrated. It spends most of its time looking for food, so it is an active hunter despite its slowness.
There are no reports of attacks on people, so it is generally not considered an aggressive species for humans.However, this could also be due to the fact that in the waters where it usually transits, it is very rare for it to coincide with humans, so caution is always advised.
Regarding their mobility, in summer they tend to move towards coastal areas, while in winter they go offshore.
Greenland shark diet
As mentioned above, the Greenland shark actively searches for its food, which is mainly composed of various types of fish, marine mammals (seals, walruses and small whales), molluscs, crustaceans, echinoderms and cnidarians. It is also a necrophagous species, which concentrates in places of accumulation where the fishing industry leaves traces of its activity. Similarly, it has been known to feed on large animals that have died from injury or have been trapped in the ice.
What aroused curiosity is that this animal, being quite slow, is able to feed on fast-swimming species.Given this, the copepod that settles in their eyes is luminescent, which serves to attract and capture their prey. However, studies are lacking to confirm these data. On the other hand, it is known that these sharks have an excellent sense of smell, a general characteristic of these fish, an advantage that makes them effective when hunting.
Reproduction of the Greenland shark
Males mature at around 2.5 meters, while females mature at around 4 meters, which is just over 150 years old. It is an ovoviviparous species, it is also called viviparous lecithotroph, since the offspring, although it develops within the mother, feeds on the egg in which it is.
Females carry between 2 and 10 young, which at birth measure between 40 cm and 1 m. Due to the lack of specific studies, there are only estimates about this. For example, young people become independent from birth.Reproduction takes place every two years, as with other sleeper sharks.
Conservation status of the Greenland shark
It is a species hunted for centuries to make liver oil, for its skin and the commercialization of meat despite its slight toxicity to humans if not treated properly beforehand . Currently, the main threat is its accidental capture in the fishing nets of other species.
The International Union for Conservation of Nature (IUCN) has declared the Greenland shark vulnerable, with a declining population trend. Among the main conservation actions, hunting has been limited in various regions, as well as mandatory release with the least possible damage in the event of accidental catches.
Photos of Greenland Shark
