1. Whale sharks are the largest fish in the world. 

    They can grow up to 40m long, but are usually around 10m- which is the roughly the size of a school bus.

  2. Its mouth can open up to 5 feet wide. 

    With such a large body, whale sharks also need a lot of food to sustain them. Their large mouths enable them to engulf large amounts of phytoplantons, krill, and other small fish. It is estimated that they need to eat around 21kg of phytoplankton a day!

  3. Their eggs hatch inside the mother shark. 

    Whale sharks are ovoviviparous. Unlike most marine animals that lay their eggs, the eggs of a whale shark hatch within the parent in the form of egg capsules. Within the capsule lies nutrients that can be found in the yolk, and once it is out of the capsule, the young shark continues to be nourished inside the mother. Only when the baby sharks are nourished enough does the mother give birth to its live young.
    Another rather shocking fact is that there is usually around 300 embryos lying within a female shark when it is pregnant, and the embryos are at different stages of development. This finding has lead researchers to think that they also have special sacks that store sperms, allowing them to fertilize the eggs selectively and gradually.

  4. They tend to swim with small fish. 

    It still remains a mystery why tuna, being the fastest moving fish in the sea, would travel with slow-moving whale sharks, however it is a common sight to see a school of tuna whenever you see whale sharks, and vice versa. Tuna have the tendency to form bait balls when they feed on smaller fish- which is the situation in which they surround their prey, forming a large ball of smaller fish from which they feed. When this happens, whale sharks tend to suck their small prey out from the bait ball, thus the tuna do serve as their food gatherers.

  5. Whale sharks have about 300 teeth, but they do not use them.

    They are filter-feeders that feed on small fish, thus do not use their teeth!

  6. The spots on the whale sharks are unique- no two sharks have the same patterns! 

    Just like fingerprints, the spots on the sharks can be used to identify individual whale sharks. This has been a method used by many researchers in situations in which they want to track populations or specific fish.