Introduction to the Whale Shark
The largest fish alive is the whale shark (Rhincodon typus), a massive but innocuous member of the Rhincodontidae family. Although they can be found in marine habitats all over the world, these sharks are primarily found in tropical oceans. They belong to the order Orectolobiformes, which also includes the carpet sharks, and are the sole species of the genus Rhincodon.
Where Do Whale Sharks Live?
All around the planet, they live in warm waters. They can be found in the Caribbean Sea, the Gulf of Mexico, and the western Atlantic Ocean, which stretches from the U.S. coast of New York to central Brazil. They can be found in the eastern Atlantic from the Gulf of Guinea to the shores of Cape Verde, Mauritania, and Senegal. The western and central Pacific, in addition to the Indian Ocean, are the sites of these sharks.
Near Pakistan, India, Sri Lanka, Malaysia, Thailand, China, Japan, the Philippines, Indonesia, Papua New Guinea, Australia, New Caledonia, and Hawaii, they were also seen off the coast of South Africa and in the Red Sea. They are found in the eastern Pacific, spanning from northern Chile to southern California in the United States.
Size and Physical Characteristics of the Whale Shark
This massive shark is said to have a maximum length of approximately 18 meters (59 ft). However, almost all of the specimens that have been examined have averaged lengths of 12 meters (39 feet) and weights that were around 15 tons (14 metric tons). The hue of the body is unique. On a dark background, light vertical and horizontal stripes create a checkerboard design, while light dots identify the body’s dark regions and fins. The head is flat and wide, with a huge mouth and a somewhat shortened nose.
Horizontally running along either side of the body to the tail are many conspicuous hard tissue ridges, usually referred to as keels. On either side of the head region, directly above the pectoral fins, are five sizable gill slits. The shark’s gill arches support the special spongy tissue inside the gill slits, which creates a special filter for feeding. From each nose hangs a barbel, a short, primitive sensory organ. The shark’s anal and dorsal fins are smaller than its big front dorsal(top) fin.
Feeding Habits of the Whale Shark
The megamouth shark (Megachasma pelagios), basking shark (Cetorhinus maximus), and whale shark are the three enormous filter-feeding sharks. At or close to the ocean’s surface, whale sharks search for food. With over 300 rows of tiny, sharp teeth in each jaw, its big mouth is well suited for filter feeding. These teeth are regarded by ichthyologists as vestigial and have no function in feeding. Seawater enters the shark’s mouth cavity and filters through the gill slits when it swims with its mouth open. Plankton and other tiny organisms are captured by the mesh-like tissue of the internal gill slits, which functions as a sieve to let water flow through and back to the sea.
The shark will occasionally shut its mouth to consume the trapped prey. When feeding, the whale shark occasionally bobs up and down with its tail down and its mouth open, allowing food and water to enter the mouth. Both zooplankton—small animals like copepods, shrimp, and other invertebrates—and phytoplankton—algae and other marine plant matter—are included in the prey that has been caught. Sardines, anchovies, mackerels, squid, and even little tuna and albacore are among the many fish and mollusks that the whale shark consumes.
Reproduction and Lifespan of Whale Sharks
Though being prone to be alone, these sharks can still be spotted in schools of hundreds. Yet they occasionally approach the coast, these species are primarily found in the open ocean. Scientists believe that whale sharks give birth to completely developed live pups, despite the lack of knowledge regarding their reproductive cycle.
The tiniest whale sharks ever measured in the wild were 55 cm (1.8 feet) long, which is probably how big they were at birth. There are roughly 16 young in each litter, although many more could be born. A female was captured close to Taiwan in the mid-1990s with around 300 kids in her uterus. As per scientific estimates, whale sharks can live anywhere between 60 and 100 years.
Are Whale Sharks Dangerous to Humans?
Humans are not in danger from these sharks. Divers have approached, studied, and even ridden numerous individual whale sharks that have not displayed any aggressive behavior. They might approach and inspect humans in the water out of curiosity. Sportfishing boats have occasionally been bumped by these sharks, although this is probably a response to the bait that the fishermen above are dangling. Boats often hit these sharks as they are swimming at or close to the surface.
Commercial fishing shows minimal interest in whale sharks. They have, however, been inadvertently caught as bycatch in some places, and they have been harvested for food in China, Taiwan, India, Pakistan, and the Philippines, where they are consumed either fresh or salted and dried. The International Union for Conservation of Nature has categorized the whale shark as endangered since 2016.