Whale shark (Rhincodon typus) - Yucatan - Mexico { 92 images } Created 31 Oct 2017

Whale shark - Requin baleine (Rhincodon typus), Yucatan peninsula, Mexico.

The whale shark (Rhincodon typus) belongs to the family of Rhincodontidae. It is the biggest present cartilaginous fish on the planet. He arranges a massive body from 3 to 15 meters length for 2 to 12 tons weight (some of them can reach 20 meters for 34 tons). The livery of this fish in checkerboards is very characteristic. The stomach and the bottom of fins is white. His mouth, being able to reach two meters in width is equipped with tiny teeth distributed on 300 rows by jaw. Five pairs of branchiales cracks filter the water to assure its breath. This shark raises two dorsal ailerons and its tail fin is said " hétérocerque ", the upper lobe is more big than the lower lobe. His geographical distribution includes waters tropical and moderated in hot of the Atlantic Ocean, the Pacific and the Indian Ocean. It is a pelagic species living in the wide in very deep water. However they sometimes group together in shallow water by the hundreds. They migrate on long distances probably for the plankton and changes in water temperature. The shark-whale feeds on small-sized preys as the plankton, the krill, but also seaweeds, small shellfish and small squids. They filter their food by swimming slowly gaping mouth. Only four species of sharks filter their food, the shark-whale, the megamouth shark, the basking shark and the manta ray.
The mode of reproduction of whale shark is still mysterious. The scientists are not able of defining if the animal is viviparous animal, oviparous or ovoviviparous, although the last mode is favored. The young shark are born formed and measure approximately 45 cms, and it reaches sexual maturity between 20 and 30 years. Because of his slow cycle of reproduction the shark-whale is threatened by overfishing for his flesh and his fins (the shark finning). He is classified "Vulnerable" by the red list of the UICN.
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