Marine Creature: Whale Shark
Kindly compiled by David Robinson of Sharkwatch Arabia & The Qatar Whale Shark Research Project
Whale Sharks (Rhincodon typus) are the largest fish in the sea.
Whale sharks are found at worldwide locations in tropical or warm temperate waters
The dermal layer of a whale shark can be up to 14cm thick, under the skin there is a thick layer of gelatinous tissue that helps to protect the whale shark from injury.
Whale sharks are ovoviviparous, which means that they produce eggs that develop inside the mother. The young then hatch out of the egg still inside the mother and then the mother later gives birth to them.
- Lifespan: Unconfirmed
- Size: 12m
- Food: Zooplankton
One mature female that was caught off the coast of Taiwan was found to have 304 young inside of her, all at different stages of development, some ready for birth and some still developing inside egg cases. Genetic testing showed that it was probable that the offspring were all sired by the same male but as the offspring were all at different stages of development, that they were fertilised at different times. This suggests that female whale sharks can store sperm after mating to use for further fertilisation at a later stage.
Feeding & Hunting
Whale sharks are filter feeders, consuming huge amounts of zooplankton. They have different feeding strategies depending on the density of plankton they are feeding on.
Whale sharks are listed as vulnerable to extinction by the IUCN. Certainly the largest threat to the whale shark is from over fishing.
Conservation Status & International Protection
International trade in whale sharks and whale shark parts are governed by CITES and some protection is afforded from countries that sign up to CMS. The importance of whale sharks as a tourist attraction is being seem around the word and many countries are offering them special protection as they are certainly more valuable alive than dead.
How can people help?
People can help by reporting encounters of whale sharks. In Arabia they can report at www.sharkwatcharabia.com or at www.whaleshark.org.au/photo-id-library/ which records whale shark encounters from all over the world.
Best places in the world to see these creatures:
- Ningaloo Reef, Australia,
- Holbox, Mexico
- Gladden Spit, Belize
- Tofo, Mozambique
- Donsol, Philippines
Scientist Profile: David Robinson
Qatar Ministry of Environment,
Save our Seas Foundation (SOSF)
Description/Background of work
Importance of work
To protect an animal an understanding of how that animal utilises its environment is necessary. The ultimate goal of the project is to provide a scientific evaluation of the whale sharks in this region with a view to increased protection throughout the region.
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