The whale shark (Rhincodon typus) is the world's largest fish, it has a history of 60 million years in which it has traveled the oceans of this world. Furthermore, the shark is unique because not only is it the only existing species of its genus but also of its family.
Nevertheless, we generally know little about this species which is cataloged vulnerable on the IUCN list. The first whale shark measuring 4.6 meters was identified, speared and captured on the shores of Table Bay, South Africa in 1828. This shark was sold for six pounds, and its holotype is shown at the Museum of Natural History in Paris. One year after this great discovery the first scientific paper on the species was written, and in 1849 the first detailed description of the whale shark was published. It was assigned the name whale shark due to the physiology of the fish; a shark with the appearance and size more typical of a whale. 

The whale shark is a solitary fish which occasionally forms groups to feed in areas with large food concentrations. Males can be found in different places while females prefer to stay in specific areas.  Its belly is white and his back is a darker gray than other sharks and has a lot of dots and horizontal and vertical white or yellow lines. These dots represent a unique pattern in each specimen, which is why they are used for identification purposes and to census the population. There are several theories on the purpose of these spots: They might be used for camouflage, as from below they can easily be confused with the light from the sky and from above they can be confused with the reflection of exterior light. Another possibility is that these distinguishing marks are a social feature for recognizing other sharks or that the pigmentation patterns are an adaptation to protect the shark from radiation, which is important for species that remain a significant part of their time on the water surface. An interesting side note on the coloring of the whale shark’s skin is that in 2007 Antonio Moreano photographed a rare albino specimen in the northern zone of the Galapagos Islands.
 
These animals are hydrodynamic with a lengthened and robust body which holds several longitudinal ridges on the head and back. The skin of a whale shark can get as thick as 10 cm. Its head is broad and flattened; its eyes are small and are located on the sides. Behind the eyes are the spiracles; respiratory openings that allow contact between the air or water and the internal respiratory system. The position of its eyes makes vision of much less importance than smell. The mouth can measure up to 1.5 meters wide. Whale sharks have about 3000 teeth in each jaw, but these are very small (less than 6mm in length) and are not used for feeding. It has five pairs of large gill slits which clefts are enormous. It has a pair of dorsal fins and pectoral fins. Its tail can measure more than 2.5 meters from side to side. The tail of an adult has a half moon shape and provides the propulsion; the upper part of the tail of younger species is larger than the lower part. These sharks use their entire body to swim, something that is not very common in fish and that make it a less efficient swimmer. The shark does not achieve a much higher speed than 5 km/h; a relatively slow speed for a fish of such enormous size. It is thought that they can grow 20 m in length and they don’t reach sexual maturity until they measure over 9 meters (at 30 years more or less). They can weigh up to 34 tons (34000 kg). Whale shaks are believed to live an average of 60 years, maybe more. Although first thought to be viviparous, and then thought to be oviparous, in 1996 it was discovered that they are ovoviviparous (the eggs remain inside the female until hatching), when a female with 300 eggs was found; the largest number of eggs registered in any species of shark. Newborn whale sharks usually measure between 40 and 60 centimeters in length, although little is known about them.

Eager to see a whale shark yourself? Visit the whale shark tours page.  

You may also be interested taking a look at the other adventure excursions we have.