Sand shark
Encyclopedia
Sand sharks, also known as sand tiger sharks or ragged tooth sharks, are lamniform shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

s of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Odontaspididae (or sometimes - but incorrectly - referred to as Carchariidae). They are found worldwide in temperate and tropical waters, including on both sides of the Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 coast, but most notably in the Western Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

 and in the Gulf of Maine
Gulf of Maine
The Gulf of Maine is a large gulf of the Atlantic Ocean on the east coast of North America.It is delineated by Cape Cod at the eastern tip of Massachusetts in the southwest and Cape Sable at the southern tip of Nova Scotia in the northeast. It includes the entire coastlines of the U.S...

. There are four species in two genera. Sand sharks are the only shark known to surface for gulps of air. They store the air in their stomachs which allows them to float motionless in the water as they hunt for prey.

Description

Sand sharks have a large second dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

. They grow up to 10 feet in adult length. A Sand Shark can reach up to 200-350 pounds, which is quite light compared to other sharks. The body tends to be brown in color with dark markings in the upper half.These markings disappear as they mature. They possess a rudimentary swim bladder - a highly unusual feature in sharks - which enables them to have fine control over their buoyancy compared with other sharks. 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 small spurs, "denticles", on either side of the jaw.

Reproduction

Sand sharks only develop two embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...

s, one in each uterus. The strongest pups eat other embryos and any other unfertilized eggs in a process called "intrauterine cannibalism
Intrauterine Cannibalism
Intrauterine Cannibalism is the first studio album by American brutal death metal band Malignancy.-Track listing:# "Rotten Seed" — 3:16# "Intrauterine Cannibalism" — 1:42# "Intestinal Sodomy" — 2:22# "Internal Corruption" — 1:48...

" before being born. They have a gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....

 period of about 9 to 12 months. A female Sand Shark becomes sexually mature when she reaches 2 meters long. At birth, Sand Sharks are already 1 meter long.

Conservation

The sand tiger shark is managed by the Highly Migratory Species Fishery Management Plan (FMP). However, sand tiger sharks have also been used for fishmeal and oil (from its liver), and its fins are used for the Asian sharkfin trade. Sand tigers are very susceptible to fishery exploitation because they aggregate in large numbers during the mating season at particular coastal spots. These aggregations have been targeted in the past by fisheries.

The sand tiger shark is a U.S. National Marine Fisheries Service species of concern
Species of Concern
In wildlife conservation, Species of Concern is an informal term, not defined in the federal Endangered Species Act. The term commonly refers to species that are declining or appear to be in need of concentrated conservation actions. Many agencies and organizations maintain lists of these at-risk...

. Species of Concern are those species about which the U.S. Government's National Oceanic and Atmospheric Administration
National Oceanic and Atmospheric Administration
The National Oceanic and Atmospheric Administration , pronounced , like "noah", is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere...

, National Marine Fisheries Service, has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...

.

Species

The family contains four species, in two genera:
  • Genus Carcharias
    Carcharias
    Sand sharks, or sand tigers, are lamniform sharks of the family Odontaspidae . They are found on both sides of the Atlantic coast, but most notably in the western Indian Ocean and in the Gulf of Maine...

    Rafinesque, 1810
    • Carcharias taurus Rafinesque, 1810 (Sand tiger shark)
    • Carcharias tricuspidatus Day
      Francis Day
      Francis Day CIE was Inspector-General of Fisheries in India and Burma and an ichthyologist.He was born on 2 March 1829 Maresfield, Sussex, UK third son of William and Ann Day. He became the medical officer in the Madras Presidency, East India Company services in 1852.Francis Day was created a...

      , 1878
      (Indian sand tiger)
  • Genus Odontaspis
    Odontaspis
    Odontaspis is one of two genera in the sand shark family, Odontaspididae. They are large-bodied sharks with long, conical snouts, broad-based dorsal and anal fins, and an asymmetrical caudal fin with a strong lower lobe. Their teeth are large, with prominent narrow cusps...

    Agassiz
    Louis Agassiz
    Jean Louis Rodolphe Agassiz was a Swiss paleontologist, glaciologist, geologist and a prominent innovator in the study of the Earth's natural history. He grew up in Switzerland and became a professor of natural history at University of Neuchâtel...

     1838
    • Odontaspis ferox (Risso
      Antoine Risso
      Giuseppe Antonio Risso , called Antoine Risso, was a Niçard naturalist.Risso was born in Nice, County of Nice, a part of the Duchy of Savoy, and studied under Giovanni Battista Balbis. He published , and . Risso's dolphin was named after him...

      , 1810)
      (Smalltooth sand tiger)
    • Odontaspis noronhai (Maul
      Günther Maul
      Günther E. Maul was a German ichthyologist and taxidermist in Portugal. Maul came to Madeira in the 1930s, and was the impetus for the construction of a large aquarium in Funchal....

      , 1955)
      (Bigeye sand tiger)

External links

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