Sand shark

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Sand sharks
Temporal range: Upper Cretaceous–Recent[1]
Sand tiger shark (Carcharias taurus)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Lamniformes
Family: Odontaspididae
J. P. Müller & Henle, 1839

Sand sharks, also known as sand tiger sharks, grey nurse sharks or ragged tooth sharks, are mackerel sharks of the family Odontaspididae. They are found worldwide in temperate and tropical waters. There are four species in two genera.

Description

Sand sharks have a large second dorsal fin. They grow up to 10 feet in adult length.[1] The body tends to be brown with dark markings in the upper half. These markings disappear as they mature. Their needle-like teeth are highly adapted for impaling fish, their main prey. Their teeth are long, narrow, and very sharp with smooth edges, with one and on occasion two smaller cusplets on either side.[2] The Sand shark can grow up to 3.2 meters (10.5ft), and most adults can weigh around 200 Kilograms (440lbs). The average life span of both sexes is only about 7 years, though they may live even longer due to their ability to live in captivity.

Location and origins

The name sand shark, comes from their tendency toward shoreline habitats, and they are often seen swimming around the ocean floor in the surf zone, at times they come very close to shore. They are often found in warm or temperate waters throughout the world's oceans, except the eastern Pacific.[1] They are also frequent the Mediterranean and Adriatic Sea in depths from 20 to 200 meters (65 to 650ft) and sometimes more. [1]

Behavior

The Sand Shark has a very unique hunting strategy. They are able to gulp air from above the surface and collect the air in their stomachs. This enables them to become buoyant and approach their prey virtually motionless. During the Day, the Sand shark stays mostly inactive. But at night, the Sand shark becomes active and resumes hunting activities.[3] Their staple is small fish, but they will eat crustaceans and squid as well. They occasionally hunt in groups, and have even been known to attack full fishing nets.

Reproduction

Sand sharks only develop two embryos, one in each uterus. The pups eat unfertilized eggs in a process called oophagy before being born. It has one of the lowest reproduction rates of all sharks and is susceptible to even minimal population pressure. For this reason, it is listed as vulnerable and is protected in much of its range.

Attacks on people

Sand sharks are not known to attack humans. If a person were to provoke a sand shark, it may retaliate defensively. Sand sharks are not aggressive. The size of the sand shark's mouth is not typically large enough to inflict traumatic wounds, however a laceration to a major artery near the surface of the skin may prove fatal.

Species

The family contains four species, in two genera:

References

  1. 1.0 1.1 1.2 1.3 Froese, Rainer, and Daniel Pauly, eds. (2009). "Odontaspididae" in FishBase. January 2009 version.
  2. Bigelow, Henry B.; Schroeder, William C. (1953). Fishes of the Gulf of Maine. United States Government Printing Office. Retrieved 30 October 2011. 
  3. "Sand Tiger Shark Profile". National Geographic. National Geographic. Retrieved 17 May 2013. 
  4. Carcharias taurus. Rafinesque, 1810. Sand tiger shark. FishBase
  5. Carcharias tricuspidatus. Day, 1878. Indian sand tiger. FishBase
  6. Odontaspis ferox (Risso, 1810). Smalltooth sand tiger. FishBase
  7. Odontaspis noronhai (Maul, 1955). Bigeye sand tiger shark. FishBase

External links

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