Sand Tiger Shark

Though the sand tiger prowls the oceans with cold, staring eyes and a mouthful of sharp teeth, and the most gruesome part of its life cycle happens before it’s even born, the shark is actually peaceable.

It also tolerates captivity, and those sharks one sees swimming round and round in aquariums are often sand tigers.

4 Incredible Sand Tiger Shark Facts

• The spotted ragged-tooth shark has an interesting life cycle. The first baby to reach 4 inches in length in the uterine horn eats its smaller brothers and sisters and any unhatched eggs.
• Because of the above, this shark’s reproduction rate is one of the lowest of all sharks.
• Recent studies suggest a slight male bias in grey nurse shark populations, with a sex ratio of approximately 1.4 males for every female, though some populations may be closer to an even ratio.
• Despite its name, the sand tiger shark isn’t a close relative of either the tiger shark, the nurse shark, or the bull shark.

Evolution and Origins

The lineage of the Sandtiger Shark dates back almost as far as that of the Goblin Shark, around 97 to 112 million years ago, and its earliest known ancestor, Carcharias striatula, had fang-like fossilized teeth that resemble those of the current species.

The sand tiger shark can be found in various regions across the globe, including the Eastern and Western Atlantic, the Pacific and Indian Oceans, as well as the Mediterranean and Adriatic Seas.

Furthermore, sand tiger sharks reproduce through internal fertilization and give birth to around two pups every other year, with one pup developing in each uterus; however, their reproductive rate is quite low compared to other sharks due to intrauterine cannibalism, where the largest embryo consumes other eggs and embryos until only one is left.

Classification and Scientific Name

The sand tiger belongs to a genus of sharks called Carcharias, and its scientific name is Carcharias taurus. Carcharias comes from the Greek karkaharos, which means jagged or sharp, and taurus is Latin for bull.

There are four species, and here are some facts about them:

Different Species

• Carcharias taurus: This is the classic sand tiger shark.
• Carcharias tricuspidatus: This is the Indian sand tiger. Biologists don’t know much about it, and many suspect that it is the same species as C. taurus.
• Odontaspis ferox: This shark is called the small-tooth sand tiger. It is found around the world in deeper waters.
• Odontaspis noronhai: This is the bigeye sand tiger shark. The bigeye sand tiger is found in deeper waters than C. taurus, and scientists don’t know much about it.

Appearance

The sand tiger has a robust, torpedo-shaped body. Its head comes to a point, with a cone-shaped snout. It’s generally about 10 feet long and weighs between 110 to as much as 661 pounds. Females are bigger than males.

The blue-nurse sand tiger swims with its mouth open, baring rows of ragged teeth that give it one of its many names. Unlike its cousin, the bigeye sand tiger shark, C. taurus’s eyes are small. The shark is light grayish-brown on top with a pale belly, and it has coppery brown spots on its body and fins.

The pectoral fins are behind the last gill opening, and it has two spineless dorsal fins and anal fins that are all about equal in size. The tail has a long upper lobe and a short lower lobe.

Distribution, Population, and Habitat

These sharks are found around the world in warm waters, mostly off the east and southern coasts of the United States, the southeastern coast of South America, the Mediterranean, and off the coasts of Africa, Australia, China, and Indochina. Though it can dive to over 600 feet, it prefers shallow waters, where it hunts stealthily and at night.

Its population has declined due to overfishing for its fins (used in shark fin soup), meat, and hides, as well as bycatch, habitat loss, and direct killing due to its fearsome appearance. The use of liver oil in cosmetics is now less common. It’s captured for display in aquariums around the world since it tolerates captivity.

Some people simply kill the shark because of its ferocious looks. It’s also caught in nets, and baby sharks are vulnerable to pollution.

Predators and Prey

Humans are the only animals that prey on these adult sharks. Baby sharks are eaten by larger sharks.

The sand tiger’s prey includes fish, smaller sharks, lobsters, squid, rays, and skates. Sometimes these sharks work together by herding fish into balls before they attack them. Sand tigers can be dangerous when they are in a feeding frenzy, for they’ll attack anything that’s nearby.

It’s also vulnerable to being parasitized by lampreys, which attach to the shark and drink its blood.

Reproduction and Lifespan

One of the reasons that sand tigers are in trouble is their unusual life cycle. Females only produce one or at most two pups at a time, and they only breed every two or three years. Before this, the male and female sharks engage in a courtship ritual that involves biting and circling.

Sand tiger sharks breed from August to December in the northern hemisphere and August to October in the southern hemisphere.

The female is gravid for about a year, then gives birth to one or two 3-foot-long pups who are immediately independent.

These sharks live about a dozen years in captivity but can live around 35 years in the wild.

Fishing and Cooking

These sharks are caught on lines, in nets, and are speared. Their fins are used to make shark fin soup.

Population

This shark’s population is decreasing, and it is considered Critically Endangered globally by the IUCN. Biologists estimate there are only about 400 breeding-age individuals off the coast of eastern Australia, which is not enough to sustain the population.