Time to learn about the ultimate deep sea shark that prefers to eat and run. Dive in to meet the small, but mighty Cookiecutter shark!
FAMILY: Dalatiidae
SCIENTIFIC NAME: Isistius brasiliensis
COMMON NAMES: Cigar shark, Cookie-cutter shark, Luminous shark
This species is named after the cookie-shaped wounds that it leaves behind on their prey.
TYPE: Fish
IUCN Red List Status: Least Concern (assessed 2017)
SIZE:
This little shark species maxes out around 1.6ft in length with females growing larger than the males. Male cookiecutters reach a maximum size of 16.5 inches while females can reach 22 inches in total length.
DID YOU KNOW:
The Cookie-cutter Shark is a facultative ectoparasite on large marine species, feeding on plugs of flesh from its temporary hosts, although it also feeds on other prey.
AVERAGE LIFE SPAN:
As with other sharks and deep water species there is much to be discovered about this shark, like their lifespan- which for now, is uncertain.
Researchers do know that these sharks are ovoviviparous- meaning they give birth to live pups after developing inside egg cases within the uterus of the mother. Their gestation period is not known but litter size is believed to be 6-12pups born measuring 5-6in (14-15cm).
DISTRIBUTION:
Cookiecutters are wide ranging tropical oceanic sharks- found in epipelagic to bathypelagic zones. These sharks are known to occur in deep water at depths more than 11482.9 ft [3500 m] deep, but are usually found from 278.9 - 11482.9 ft [85-3500 m]. Like other deep sea animals, these sharks spend the day in deeper waters then migrate toward the surface at night to feed.
Cookiecutters are often found near islands, which may indicate pupping grounds or correlate to where prey concentrations are higher.
DID YOU KNOW:
Cookiecutters are small with large green eyes and are counterilluminated (ventral light organs makes them appear darker above and lighter below), which helps them attract their prey. When in range, this cigar-shaped shark takes small circular or "cookie cutter", bites of flesh using their specialized teeth and jaws.
DIET:
Cookiecutter sharks have one of the most unique feeding methods, especially when compared to more widely known or 'classic shark' species.
As mentioned above, cookiecutters are perfectly adapted for life in the deep sea and have unique adaptations that help them find prey. Thanks to their coloration and light given off by glowing photophores, prey animals are attracted within striking range for the shark.
Using their sharp point upper teeth and suctorial lips, the shark attaches itself to its prey then spins its body removing a cookie-shaped plug of the flesh with its larger serrated bottom teeth.
Common prey items include: large fishes such as marlin, wahoo, tuna, as well as other sharks, rays, seals, whales, and dolphins; there are also reports of this shark leaving marks on submarines! In addition to these 'to-go' style meals, these sharks also feed on whole squid, crustaceans and other smaller deepwater fish species.
CONSERVATION:
This shark species is occasionally caught as bycatch in oceanic trawl and longline fisheries during the nighttime hours as they migrate vertically to hunt.
Due to its size and deep-water habitat these sharks are not considered harmful to humans. However, there is a case (GSAF 2009.03.17) in which a long-distance swimmer was bitten by a Cookiecutter shark. In fact, according to the International Shark Attack File, the cookiecutter has been involved in four confirmed, unprovoked bites, all of which occurred in Hawaii. They are reported to be very active and can bite if caught.
Check out more in-depth information about
this species with below source links and organizations!
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