Whale Shark: The biggest fish in the world.
The eternal question: is it a shark or a whale?
If we look carefully to the whale shark anatomy we can see the following characteristics:
- 5 Gills in front of the pectoral fins.
- If we look at the caudal, dorsal, pelvic, anal and pectoral fins, it has the exact amount and location that the SHARKS.
So, It’s a shark, therefore, the biggest fish in the world!
Scientific name: Rhincodon typus
Longevity: between 70 and 100 years
Anatomy of the whale shark
Its weight goes around 21 tons, or the equivalent of the weight of 4 african elephants, and it measures around 12 meters long. There are a lot of histories that talk about 18 meters long specimens, but there aren’t any records or scientific proof of that, we all know how folktales are.
The most characteristic is their skin
Thick as 10 cm, covered with its own unique pattern of yellow/white dots and stripes. Like it were fingerprints. These patterns are used for their identification
Their big mouth
It’s 1,5m wide, with 300 to 350 rows of tiny teeth that don’t have any important role for their feeding. The 20 rows of filter pads are the responsibilities of filtering their food. Everything that is bigger than 2-3 mm of diameter gets trapped in them.
It can be 2.5 m long. But, despite its size, they are slow swimmers, moving just 5 km/h.
In the young specimens, the top fin is bigger than the lower one. Meanwhile, on the adults, it has a half moon shape, for better propulsion.
How do the whale shark feed?
First of all, they target their food through olfactory cues. And then, through filtration, they feed themselves.
It can be a ram filter feed or gulp in stationary position, commonly known as “bottle position”. In other words, they put themselves in a vertical position and then move up and down pumping and filtering actively water.
What do they eat?
Plankton (organisms that float in the water), like copepods, krill, fish eggs and red crab eggs.
And also nekton (organisms that actively swim in the water) like small fish (anchovies, mackerel, sardines) or squids.
Found in all tropical and subtropical warm waters (21º – 30ºC) except from the Mediterranean sea.
They are considered pelagic animals, but in certain periods of the year, they migrate to offshore areas, like the Holbox island in Quintana Roo, where we are so lucky to be able to see them.
How do they reproduce?
They reach their sexual maturity when they reach 9m long. For the females around 30 years old, for the males, 25 years old.
They are ovoviviparous. The newborn whale sharks are between 40 and 60 cm big, but there is not so much information about them, as they are rarely seen.
Curiosity: A single female can grow up to 300 embryos inside before hatching their young live.
Protect the whale shark
The population of whale sharks is unknown, but in 2016, they were classified on the IUCN Red List as endangered.
Therefore, fishing, importation and exportation of whale sharks for commercial purposes is forbidden and punished.
Whale sharks are highly valued in Asian market as:
- Meat, known as “Tofu shark”.
- Fins used for fin soup
- Fins as prize display
How can we protect them?
- Enhance Eco-Tourism, where the species are protected and they help local economies.
- Any activity related to them should be conducted listening and respecting the local recommendation for their protection.
- Ban shark finning.
- Create shark sanctuaries.
Now that you have a deep understanding of the whale shark, it’s the moment to meet it in person.
Every year, from June to September, a big congregation of these wonderful animals visit us in front of Holbox island. It’s one of the biggest ones in the world and we are so privileged to be able to visit them. Are you coming? Contact us for more information.