There are few places in the world where you can find the geological characteristics necessary for sheltering whale sharks.
The whale shark is the largest existing fish in the world. It has a massive, long body with grey or blue colouring on its back, and round spots and clear horizontal or vertical lines (white or yellowish) on its belly, which is why it is known locally as “domino” and in other places it is also known as chequered or draught fish, in both cases due to the domino and chequers board games. Each individual shark has a unique pattern which makes it easy to identify, since the pattern doesn’t change as it grows. These marks are possible a result of a genetic relationship with other sharks of the Orectoibiformes species, such as the cat shark (Ginglymostomatidae). The sharks are visually highly developed and the distinctive marks on deep water species could be an important social attraction, or signs of social stature in the recognition process. Another possibility is that these pigmentation patterns could be an adaptation to protect them from radiation, which is important for those species that spend a significant part of their time on the water surface.
The whale shark is a slow moving species, staying close to the water surface, which enables us to observe them from close quarters and even swim with them. Their slow movement is part of their eating habits, since they feed by filtering large amounts of water that contain a wide variety of plankton and nekton, including small crustaceans such as krill, crab larva, small fish such as sardines, anchovies, mackerel and occasionally larger prey such as small tuna fish and squid. Phytoplankton and macro algae can also feature as part of their diet.
Sightings of the population located to the north east of the Yucatan peninsula begin in Cabo Catoche during May and in Holbox from mid-June to September. This population has both males and females and on occasions the males show signs of reproduction; that is why it is even more important to protect this particular population.
For more information please visit: www.domino.conanp.gob.mx