Feel the experience, swim with the harmless Whale Shark
Once there, you can easily find a fisherman with a "lancha" (a small motor-powered wooden fishing boat) who uses his not-so-quaint GPS locator in order to find the spot where the whale sharks, known locally as Dominos are feeding. After about an hour of motoring, you will find yourselves in the middle of the ocean, with no land in sight. Suddenly, there are four or five whale sharks slowly swimming.
The whale shark is a the biggest shark and the biggest fish. It is NOT a whale. It has a huge mouth which can be up to 4 feet (1.4 m) wide. Its mouth is at the very front of its head (not on the underside of the head like in most sharks). It has a wide, flat head, a rounded snout, small eyes, 5 very large gill slits, 2 dorsal fins (on its back) and 2 pectoral fins (on its sides). The spiracle (a vestigial first gill slit used for breathing when the shark is resting on the sea floor) is located just behind the shark's eye. Its tail has a top fin much larger than the lower fin.
The whale shark has distinctive light-yellow markings (random stripes and dots) on its very thick dark gray skin. Its skin is up to 4 inches (10 cm) thick. There are three prominent ridges running along each side of the shark's body.
This enormous shark is a filter feeder and sieves enormous amounts of plankton to eat through its gills as it swims.
The whale shark is up to 46 feet (14 m), weighing up to 15 tons. The average size is 25 feet (7.6 m) long It is the largest fish in the world. Females are larger than males (like most sharks).
Whale sharks have about 3,000 very tiny teeth but they are of little use. Whale sharks are filter feeders who sieve their tiny food through their large gills.
DIET AND FEEDING HABITS
The whale shark is a filter feeder that sieves small animals from the water. As it swims with its mouth open, it sucks masses of water filled with prey into its mouth and through spongy tissue between its 5 large gill arches. After closing its mouth, the shark uses gills rakers that filter the nourishment from the water. Anything that doesn't pass through the gills is eaten. Gill rakers are bristly structures (the thousands of bristles are about 4 inches or 10 cm long) in the shark's mouth that trap the small organisms which the shark then swallows. The water is expelled through the sharks 5 pairs of gill slits. The prey includes plankton, krill, small fish, and squid. The shark can process over 1500 gallons (6000 liters) of water each hour.
Whale sharks are solitary creatures. Groups of whale sharks have only rarely been seen.
Whale sharks live in warm water (near the equator) both along the coast and in the open seas. They spend most of their time near the surface.
Whale sharks are found worldwide in the warm oceans from the equator to about ±30-40° latitude. They are not, however, found in the Mediterranean Sea.
Whale sharks are sexually mature at 30 years old. This is the age at which they are able to mate and reproduce.
WHALE SHARK ATTACKS
Whale sharks are harmless to people and usually indifferent to divers.
It has been estimated that whale sharks may live up to 100 - 150 years.
The whale shark is a docile fish who will not attack, even on provocation. Despite their impressive appearance, they are harmless to humans. They are mainly solitary in nature, they roam widely and are often difficult to find. The expedition from Isla Holbox is an exceptional adventure. Being in the presence of these great creatures, with enough time to observe and enjoy them, is a special privilege indeed. Please look, take pictures, enjoy, but as with many of the wonders of the ocean, please do not touch them or harass them in any way!
For several years now, whale sharks have been coming to the northern tip of the Yucatan peninsula to feed and mate during the months of May through October. Tourism based on whale shark watching has increased dramatically in the last few years and Government agencies have taken steps to protect these magnificent animals so that the species will not be harmed and so they will continue to return to this area. For that reason, Holbox has recently been named by the Mexican government as the only port that can offer trips to swim with the whale sharks and there are strict rules against scuba equipment being used to view them in the area. Local guides have been trained to give tours that are as safe for the whale sharks as they are for their human visitors.
Ask around at the docks or downtown for someone to take you to the whale sharks. The Villas Paraiso del Mar and Casa Sandra, can arrange an excursion to see these magnificent creatures. Be prepared to spend about five to six hours on the water, with all that entails. Most tour guides will provide drinks, but be sure to ask before you go. And don't forget a hat and sunscreen!