The whale shark (Rhincodon typus) is an absolutely remarkable species within the shark group. Although it belongs to these feared animals, it is paradoxical that, being the largest fish that exists today, it does not represent any type of danger for humans, since it is not at all aggressive and its diet food is far from including large prey. This extraordinary animal is today the only individual belonging to the family Rhincodontidae and corresponding to the genus Rhincodon.
Unfortunately, although it has some natural predators, it is really the human being who is responsible for the drastic decline in its population, since they are hunted for the trade of their body products, such as liver oil, which was used in a way to polish the hull of boats or clean boots.We invite you to continue reading this PlanetAnimal breed sheet in which you will discover many interesting aspects about the characteristics of the whale shark, its customs and much more.
Origin
- Africa
- America
- Asia
- Europe
- Oceania
Whale Shark Features
As we mentioned, it's currently the biggest fish in the world, but how big is the whale shark? On average, it is about 12 meters long, although one individual measuring 20 meters has been recorded. Its body is fusiform, with a tendency to widen in the center and to narrow towards the extremities. The size of the whale shark is therefore really impressive.
Its back is dark, with a bluish-gray or blue-gray color and even greenish-brown in some specimens.On the entire upper body there is a pattern that simulates a chessboard, in which white or yellowish spots and lines stand out. As for the ventral region, it is totally white.
The skin of the whale shark is quite thick, about 10 cm. It presents on it dermal denticles, which are scaly placements, which facilitate movement thanks to its hydrodynamic function, but also serve as protection which, together with the collagen system that is found under the integument, makes it a fairly resistant animal to attacks. .
Although the characteristics of the whale shark mentioned are truly remarkable, there is no doubt that the most representative is its mouth. The latter is very wide and flat and measures up to 1.5 meters. Inside it has a large number of rows of small hook-shaped teeth. In addition, it has two dorsal fins, one considerably more developed than the other, powerful pectoral fins and a crescent-shaped caudal fin.
Another important characteristic of the species is its particular longevity, as it is estimated that the whale shark has a life expectancy of around 100 years.
Where does the whale shark live? - Habitat
The whale shark is a cosmopolitan species that inhabits tropical and warm temperate waters, so it has a circumtropical distribution in all seas that have these characteristics, except the Mediterranean. Sometimes, in their migratory movements, they can move a little further north or south.
In some areas in particular, many individuals of this species have been sighted, such as: Arabian Gulf and Gulf of Oman, Western Australia, Darwin Island in the Galapagos, Quintana Roo in Mexico, province of Inhambane in Mozambique, Philippines, Mahé in the Seychelles, Gujarat in India, Taiwan and southern China. The largest population of whale sharks is estimated to be found in the Indo-Pacific Ocean, while only 25% is distributed by the Atlantic.
In contrast, the whale shark's habitat can be coastal or oceanic, and the water temperatures where it is most commonly seen are between 26 and 30 ºC. In fact, it is very rare to see it in areas where the surface water temperature is below 21 ºC. In addition to being present in shallow and surface waters, it can also dive to almost 2000 meters.
Habits of the whale shark
The whale shark has mainly epipelagic habits, which means that it tends to stay between the surface and 200m deep. Generally it is solitary, although groups with considerable numbers of individuals have been seen. Regarding its mobility, although it travels long distances, there are no definite migration patterns, there are variations in the places it moves to and the recurrence of time.
It's a particularly docile animal with people, so they pose no risk to us; in captivity, they even express closeness to caregivers.They would be able to learn certain behaviors and inspect the nets used to catch other fish.
Despite its large size and ability to swim long distances for many hours, it moves at slow speeds compared to other species. Typically, it spends the day near the surface and swims deeper at night. Day and night, as well as climate-induced temperature changes, affect the whale shark's swimming paths.
What does the whale shark eat - Whale shark diet
This shark is one of the few to feed by filtration, so its ecological role is different in this regard compared to other shark species, such as the white shark. In general, it consumes small prey, such as:
- Krill
- Mainly crab larvae
- Medusa
- Squid
- Anchovies
- Mackerel
- Thon
- Sardines
To catch his food, he can do it while swimming, but it is common for him to do it in an upright position without swimming, by partially or totally opening his mouth and sucking the water in which his is. food. Then it closes their mouth and expels water through its gills, so that prey is trapped in the denticles to be swallowed later. Another way they feed is to come to the surface, where there are accumulations of plankton or small fish, opening their mouths leaving the upper part above the water and swimming to collect the food . These forms of feeding do not require the use of teeth, so they play no significant role in the diet of the species.
Learn all the details about whale shark feeding in this other article.
Does the whale shark eat humans?
No, in fact we have already seen that it is a very docile animal with humans. Their preferred food is smaller prey, so humans are not in their diet.
Reproduction of the whale shark
For a while there was confusion about what type of animal the whale shark is in terms of reproduction, however today it is known that it is ovoviviparous, that is- that is, the eggs develop completely inside the mother until the time of birth. Another extremely interesting aspect of the species is that the female is able to store sperm and fertilize at different times, which is why she can have eggs with embryos at different stages of development. In fact, a female can have up to 300 young at different stages of growth. So is the whale shark a mammal? No, the whale shark is a fish, not a mammal.
On the other hand, studies are lacking to know precisely the breeding season of the whale shark, as well as the preferred regions, nor is it known at what age it reaches sexual maturity.
Whale shark conservation status
The threats to this animal are related to its fishing for consumption or the marketing of its body parts. It is also common for them to get caught in the fishing nets of other species, so they end up being caught and killed. In addition, its large size and its usual presence on the surface make accidents with boats recurrent.
The International Union for Conservation of Nature (IUCN) has declared the whale shark endangered and its global population is trending downward. Conservation actions include its inclusion in agreements and treaties that aim to protect it.
Other factors affecting the species are water pollution, oil spills, tourism and climate change.