Speartooth shark Facts

Speartooth shark Facts
Speartooth shark belongs to the group of sharks known as requiem sharks. It can be found in the Australia and Papua New Guinea. Speartooth shark inhabits fast flowing tropical rivers and estuaries. These sharks are threatened by habitat loss, pollution of the water, recreational hunt and by-catch (they end up trapped in the fishing nets by accident). Some studies indicate that current population of speartooth sharks consists of around 2500 animals. Speartooth shark is on the list of endangered species.
Interesting Speartooth shark Facts:
Speartooth shark can reach 8.2 to 9.8 feet in length.
Backs of speartooth shark are gray-colored. Ventral side of the body is white. Eyes are encircled with white rings. Pectoral fins are covered with black blotches.
Speartooth shark has wide head and flattened snout with small, black eyes. Streamlined, robust body ends with asymmetrical tail. Speartooth shark has 5 gill slits.
Speartooth shark has 26 to 29 rows of teeth in the upper jaw and 27 to 29 rows of teeth in the lower jaw. Teeth in the upper jaw are wide, triangular and serrated on the edges. Teeth in the lower jaw are narrow, serrated only near the tips and spear-shaped, hence the name - speartooth shark.
Skin of speartooth shark is covered with densely arranged, overlapping denticles (type of scales). They are oval-shaped and have 3 to 5 horizontal ridges on the surface.
Speartooth shark can be active both during the day and night because it lives in murky waters where difference between the day and night cannot be easily determined.
Speartooth shark relies on the electro-receptors (called ampullae of Lorenzini) to detect movement of the prey (fish) in the water.
Speartooth shark is a carnivore (meat-eater) that feeds on the fish (gobies, gudgeon, threadfin and croaker) and crustaceans (prawns).
Unlike other species of sharks, speartooth shark uses tidal currents to move in the water. Flooding tides carry shark upstream, while ebbing tides return it back (move it downstream). Relying on the tidal currents, shark can travel 6.2 to 7.5 miles in both directions. This method of movement preserves energy. Speartooth shark uses large dorsal fin to maneuver in the fast currents.
Main predators of speartooth sharks are large species of sharks and humans.
Speartooth shark does not attack humans.
Speartooth shark migrates toward the shore to reproduce.
Speartooth shark is a type of viviparous shark (female gives birth to live sharks). Babies are born from October to December. They are usually 20 to 23 inches long at birth and they can survive in the waters with increased salinity while they are young. Speartooth sharks usually grow 7.5 inches in length per year.
From the 1982 to 2005, only 108 speartooth sharks were recorded. Adult speartooth shark has never been captured (all collected specimens were young).
Life span of speartooth shark is unknown.

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