Tả về cá mập sandbar(bằng tiếng anh)

@hanguyenkhanh@king of darkness 

The sand shark or brown shark is a subspecies of the Requiem shark in the family Carcharhinidae, native to the Atlantic and Indo-Pacific oceans. They are one of the largest coastal sharks in the world, with a large triangular dorsal fin and striking brown color. It is also known as Carcharhinus plumbeus. they have long, narrow and sharp teeth of the family Odontaspididae (here, Odontaspis ferox). The body tends to be brown with black spots on the upper half. These marks disappear as they mature. Their needle-shaped teeth are well adapted for catching fish, their main prey. Their teeth are long, narrow, and very sharp with smooth edges, with one and sometimes two smaller wheels on either side. Sand sharks have a large second dorsal fin. Sand sharks can grow up to 3.2 m (10 ft) long. ft) and most adults can weigh around 200 kg (440 lb). The average life expectancy of both sexes is only about 7 years, although they can live longer in captivity. The sand shark or brown shark is a subspecies of the Requiem shark in the family Carcharhinidae, native to the Atlantic and Indo-Pacific oceans. They are one of the largest coastal sharks in the world, with a large triangular dorsal fin and striking brown color. It is also known as Carcharhinus pumbeaus.
1. location and origin
True to its name, this shark prefers to live on the sandy bottoms of coastal areas, and is known for its ability to move seasonally like many other requiem sharks. Because of its high basal weight-ratio fins, the sand shark is the target of sport and commercial evaluators, but it has a long growth and breeding cycle that makes it the choice for protection in many areas. .
2 Behaviors
Sand sharks have a unique hunting strategy. It can swallow air from the surface and collect air in its stomach. This allows them to become afloat and approach prey almost motionless. During the day, the sand shark is nocturnal, it is active and continues its hunting activities mostly inactive, but at. They are mainly small fish, but they will also eat crustaceans and squid. They occasionally hunt in groups (groups), and have even been known to attack full fishing nets.
3 Reproduction
Sand sharks develop only two embryos, one uterus on each side. The largest and strongest embryos consume their siblings in the womb (cannibalism) before each live one is born. It has the lowest reproduction rate of all sharks and is easy to breed. affected by minimal population pressure, it is therefore classified as vulnerable and protected for most of its range.
4 Attack on people
Sand sharks do not know how to attack humans. If one provokes a sand shark, it may retaliate defensively. Sand sharks are generally not aggressive but will harass breeding divers. In North America, divers regularly visit World War II-era shipwrecks to dive with the Sand Tiger shark that caused the wreck to be destroyed.
5 Conservation
A recent report from the PEW charity credits shows that a new management method used for dwindling large mammals can determine the age of sharks. Due to the life-use nature of sharks, methodological career information, such as hardware maximum gain, may not be sufficient to rebuild depleted shark populations. Several approaches to regulatory oversight are used to reverse the decline of large mammal species that may be associated with sharks, including the banning of cute species and the international frugal trade. economic.
The sand shark's natural enemies are tiger sharks, and sometimes great whites. Their diet includes rays and crabs. Females have embryos in the yolk sac of the placenta. The sand shark's breeding cycle is about once every three years, with an average of eight. Mother's pregnancy period is 1 year.

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