Whale shark
What is a whale shark in a nutshell?
The whale shark (Rhincodon typus) is the “gentle giant” of the ocean! It is not a whale but the largest known extant fish species. The name of this shark refers to its size, as large as some whales, and also to the filter-feeding strategy, similar to that of whales.
Where does it live?
The whale shark lives in open waters of the tropical oceans and rarely in seawaters below 21°C.
Except for the Mediterranean Sea, it can be found in all temperate and tropical oceans around the world and it migrates thousands of miles to reach different feeding grounds.
Does it have big and dangerous teeth?
It has a very large mouth, but no real teeth! It has over 300 rows of tiny “vestigial teeth”, which are residuals of teeth not lost during the evolution (like our sacrum bone, a vestigial tail!), but the whale shark does not use them to eat. It cannot bite!
How and what does it eat?
It has many filter pads located in the inner part of the five large pairs of gills. The whale shark uses the pads to filter feed the particles into the water. This means that plankton, eggs, larvae, small fishes, and whatever particle bigger than the pores of the pads are retained into the mouth of the shark, while the water passes through the gills and flows back into the sea. Not all sharks are predators with big teeth! A similar feeding strategy is carried on even by the basking shark and the megamouth shark.
How does a female whale shark give birth?
The whale shark is ovoviviparous, this means that a female makes eggs that remain into the body; they then develop into baby sharks and the mother gives birth to pups that are not all born at once.
What does the whale shark skin look like?
Its skin is dark grey on the back, while the belly is white-pale grey. The peculiar pattern of the skin with white spots and stripes is unique to each individual and in Madagascar whale sharks are called “marokintana”, which in Malagasy means “many stars”. The stunning spot pattern actually looks like a night sky full of stars.
Is the whale shark an endangered species?
Yes, unluckily it is. It is considered endangered by the IUCN due to the impacts of fisheries, bycatch, and vessel strikes. Like many other species of sharks, the whale shark is deliberately caught for its fins, considered a delicacy in Asia. Its ocean home is also in danger and this affects its survival: from climate change to plastic pollution, the list of threats is sadly long.
Do you want to help to study the whale sharks and contribute to their conservation?
If you meet a whale shark, don’t touch it and swim slowly and carefully around it without splashing, letting it move freely. They are shy animals, not harmful to humans! On the contrary, we can scare them!
Have a look at the Madagascar Whale Shark Project, read what they do, and follow the code of conduct they provide. If you want to support them, make a donation or adopt a whale shark!
If you meet a whale shark and you have taken photos or videos, you can also help in identifying the single specimens, contributing to the Wildbook for Whale Sharks, developed by Wild Me. The beautiful spot pattern of the whale shark body is used as a fingerprint, to identify the single specimens: the left-side spot pattern is the most important, especially the area above the left pectoral fin.