Another Omnivorous Shark: Whale Sharks Eat Their Greens, Too!

Jan 22, 2019, 08:53pm

Melissa Cristina Márquez

The internet (sort of) broke when research came out that the second smallest member of the hammerhead family, bonnethead sharks (Sphyrna tiburo), eat and digest seagrass. This made them the first known omnivorous shark. But it’s about to be joined at the dinner table with a larger shark species: the whale shark (Rhincodon typus).



Whale sharks hold many animal kingdom records, as they are the largest species of shark, reaching lengths of 30 feet or more and weighing in at more than 20 tons. Their starry constellation pattern makes it one of the most recognizable of the sharks in the carpet shark family, Orectolobidae. The carpet sharks are a diverse group with varying sizes, looks, diets, and habits. Preferring warm waters, whale sharks are seen in all tropical seas, and are famous for their spring migration to various “hot spots” around the world, such as Ningaloo Reef off Western Australia.

Although their size may scare many, they are a gentle giant and a filter feeder. It engorges itself by filtering massive amounts oceanic water to eat krill, fish eggs, sometimes small fish, squid, or prawns. It was thought they were carnivorous like all other sharks… until now. Researchers in Japan recently uncovered that whale sharks diets are a mixture of fish, sea plants, and sometimes they even periodically fast! Why the fast is a mystery, although it may be either by choice or because they just can’t find enough food to sustain themselves.

If it’s the latter, it isn’t good. Whale sharks have been classified as Endangered by the International Union for the Conservation of Nature Red List of Threatened Species™. The IUCN Red List is the “world's most comprehensive inventory of the global conservation status of plant and animal species,” according to their website, and they recently assessed 31% of sharks and rays to be threatened with extinction, an increase from the previous 25% number. Whale shark numbers worldwide have gone down due to a number of human-related threats such as fishing, fishery bycatch, vessel strikes, and other more local or regional threats.



More:
https://www.forbes.com/sites/melissacristinamarquez/2019/01/22/another-omnivorous-shark-whale-sharks-eat-their-greens-too/#45f189b643c3