Whalesharks a gentle giant of the sea

rhincodon_typuswhaleshark2The whale shark, Rhincodon typus, is a slow filter feeding shark that is the largest living fish species. It can grow up to 12.2 m. (40 ft.) in length and can weigh up to 13.6 tonnes (15 short tons). This distinctively-marked shark is the only member of its genus Rhincodon and its family, Rhincodontidae (called Rhinodontes before 1984), which is grouped into the subclass Elasmobranchii in the class Chondrichthyes. The shark is found in tropical and warm oceans and lives in the open sea and can live for about 70 years. The species is believed to have originated about 60 million years ago.
The whale shark inhabits the world’s tropical and warm-temperate oceans. While thought to be primarily pelagic, seasonal feeding aggregations of the sharks occur at several coastal sites such as Gladden Spit in Belize; Ningaloo Reef in Western Australia; Útila in Honduras; Donsol, Pasacao and Batangas in the Philippines; off Isla Mujeres and Isla Holbox in Yucatan Mexico; Ujung Kulon national Park in Indonesia; Nosy Be in Madagascar and the Tanzanian islands of Pemba and Zanzibar. Though it is often seen offshore, it has also been found closer to shore, entering lagoons or coral atolls, and near the mouths of estuaries and rivers. Its range is generally restricted to about ±30 ° latitude. It is capable of diving to depths of over 700 metres (2,300 ft). The whale shark is generally solitary yet occasionally aggregating in groups when feeding at sites with abundant food.
[edit]Anatomy and appearance

As a filter feeder it has a capacious mouth which can be up to 1.5 metres (4.9 ft) wide and can contain between 300 and 350 rows of tiny teeth.[4] It has five large pairs of gills. Two small eyes are located towards the front of the shark’s wide, flat head. The body is mostly grey with a white belly; three prominent ridges run along each side of the animal and the skin is marked with a “checkerboard” of pale yellow spots and stripes. These spots are unique to each whale shark and because of this they can be used to identify each animal and hence make an accurate population count.
The whale shark is an active feeder, targeting concentrations of plankton or fish. It is able to ram filter feed or can gulp in a stationary position. The shark can circulate water at a rate up to 1.7 L/s (3.5 U.S. pint/s). This is in contrast to the basking shark, which is a passive feeder and does not pump water; it relies on its swimming to force water over its gills.

“A whale shark is not a man eater.The first insights into the world of the whale shark, one of the rarest and most mysterious creatures on earth, came at Ningaloo within minutes of equipping it with the daily diary, in late May this year. Clipped to its dorsal fin and retrieved by hand a few hours later, the diary reported every action second-by-second to the research team. This species, despite its enormous size, are actually quite gentle and can be playful with divers. There are unconfirmed reports of sharks lying still, upside down on the surface to allow divers to scrape parasites and other organisms from their bellies. Divers and snorkelers can swim with this giant fish without any risk apart from unintentionally being struck by the shark’s large tail fin.
The whaleshark inhabits The Bay Islands in Honduras, Thailand, the Philippines, the Maldives, the Red Sea, Western Australia (Ningaloo Reef, Christmas Island), Belize, Tofo Beach in Mozambique, Sodwana Bay (Greater St. Lucia Wetland Park) in South Africa, at the Galapagos Islands, Mexico, Seychelles, West Malaysian, Sri Lanka and in Puerto Rico.

The female may carry about 300 pups and giving birth to live young each of which are about 40 centimetres (15.7 in) to 60 centimetres (23.6 in) long. These sharks may live  to be over 100 years if man will leave them alone. The species is considered vulnerable by the IUCN.

All fishing, selling, importing and exporting of whale sharks for commercial purposes has been banned in the Philippines since 1998,] India in May 2001,and followed by Taiwan in May 2007.

Excerpts from http://en.wikipedia.org/wiki/Whale_shark

Image courtesy of http://upload.wikimedia.org/wikipedia/commons/1/18/Rhincodon_typus.jp

Worldwide study and protection of whale sharks through an online global photo ID library, housed on this website http://www.whaleshark.org


1 Comment

  1. November 7, 2008 at 6:17 am

    […] Whalesharks a gentle giant of the seaKnown as a deity in a Vietnamese religion, the whale shark is called “Ca Ong”, which literally translates as “Sir Fish”. In Mexico, and throughout much of Latin America, the whale shark is known as “pez dama” or “domino” for its … […]

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