Whale Shark (Rhincodon typus)
The Whale Shark is the world's largest fish; it grows to 40ft long (12m) and can weigh over 20 tonnes. Whale Sharks have a wide flat head, shaped like a blunt square, with a very wide mouth in front and small eyes on the sides. The mouth is lined with numerous rows of very small teeth. Whale Sharks have a large dorsal fin more than halfway back on their bodies, followed by another smaller fin near the tail. Three ridges run along each side of the Whale Shark from the head to the base of its tail. The tail itself is crescent-shaped.
The skin of a Whale Shark is distinctively patterned. The back of the fish is grey to grey-brown, paling to white or yellowish on the underside. Thin, vertical and horizontal white lines join white spots on the back. Research has shown that the spot pattern is unique to individual fish 1.
Whale Sharks eat small fish, squid, pelagic crustaceans and plankton which they sieve from the water. The shark sucks in a mouth full of water, closes its mouth and pushes the water out through its gills, which are specially evolved for filter feeding.
Rhincodon typus is an oceanic species, inhabiting tropical and warm open ocean habitats worldwide. It is often seen on offshore banks or cruising along drop-offs, cliffs or walls. Whale Sharks are migratory and seasonal gatherings have been observed at sites in Australia, Africa and Central America, usually associated with events such as coral or fish spawning which provide abundant plankton food. When not at these gatherings, Whale Sharks are usually observed singly. They are known to be slow swimmers.
The life-cycle of the whale shark is not well known.
Various conservation measures are in place globally to protect the worlds largest fish, and public awareness of the species is growing, thanks in part to several live aquarium specimens on display around the world. Dive tourism with particular emphasis on Whale Shark encounters is also growing around the world. The world population of Whale Sharks is unknown but they are targeted by commercial fisheries in parts of Asia, and accidentally captured in other fisheries.
The international trade of Whale Sharks and their products has been controlled since 2003 by the Convention on International Trade in Endangered Species (CITES), where Whale Sharks are listed under Appendix II. In 1999 the Whale Shark was listed on Appendix II of the Bonn Convention for the Conservation of Migratory Species of Wild Animals (CMS). The UK has signed both of these treaties on Bermuda’s behalf. In local waters Whale Sharks are fully protected under the 2003 Bermuda Protected Species Act. The IUCN Red List of Threatened Species lists the Whale Shark as globally Vulnerable A2bd+3d.2