Whale Sharks
by Krysta CardinaleThe whale shark is the world’s largest fish. It is typically curious to humans, but harmless. Even though this species is massive in size, it is not a whale at all but a shark. It is a slow filter feeding fish, and has large gills. Whale sharks are mainly found in warm tropical waters.
Physical Features
A titan among the oceans’ fish, the whale shark can reach lengths over 50 feet and weight up to 15 tons. Its mouth is located at the front of the head, and can be up to 4 feet wide. Most other sharks have mouths found on the underside of the head. The shape of their heads is flat and wide with a rounded snout. They also have relatively small eyes. Whale Sharks do have very small teeth despite their filter feeding ways. They have 3,000 tiny teeth that are almost never used.
Since the whale shark is a fish, it has gills. These gills are more like five large slits on either side. While this animal lies on the ocean floor, it has a gill right behind its ear to breathe out of called a spiracle. This shark has two dorsal fins on its back, one larger one and a smaller one by the tail. It also has two pectoral fins, one on either side. Whale sharks’ tails have a larger upper fin than lower.
In addition to their remarkable size, these animals provide an unexpected surprise, their skin. Most sharks have very abrasive, sand papery scales that are rough to the touch. Whale sharks have relatively smooth dark gray skin. They also have very distinct yellow markings on their bodies. They have an alternating pattern of vertical stripes and dotted lines. This shark has a very thick skin which is up to four inches deep. It also has three well-defined ridges along each side of its body.
Behavior
Whale sharks are harmless surface dwellers. They roam the world’s warmer seas feeding on tiny marine animals that are filtered from the water. The shark swims with its mouth open sucking in large amounts of water containing micro organisms. This species has gill rakers that strain out the water through its gill slits, catching any food. They have thousands of gill rakers in their mouths. Gill rakers are 4 inch long bristles. The whale shark’s diet typically consists of plankton, krill, squid, and small fish.
This shark is a loner, and is rarely found in groups only when it is feeding. These animals are curious and often tolerate the close approach of human divers. Some even allowing divers to ride on their backs. Occasionally annoyed, this species will dive down deep into the murky water losing their passengers.
Whale sharks do reproduce with live births. They become sexually mature at about the age of 30 years. Their pups or babies are born about 2 feet long. Pregnant females have been reported as having up to 100 pups inside of them. Their lifespan is generally 100-150 years. This species only encounters a possible mate about two times in its entire life.
Unlike most sharks that just use their tails to swim, the whale shark uses its entire body back and forth. They are very slow swimmers, gaining speeds of only 3 mph.
Habitat
With few exceptions, whale sharks are found predominantly in warm tropical waters around the equator. However, they cannot be found in the Mediterranean Sea. They are surface swimmers, and enjoy both coastal and deep waters. Males generally range over larger distances compared to females who remain in more specific territories.
