Scientists were amazed to find whale sharks consumed seaweed in addition to krill at Ningaloo Reef, Western Australia. Credit: Andre Rerekura, Australian Institute of Marine Science
Marine biologists have actually discovered that whale sharks consume plants, making the popular species the largest omnivore in the world.
Whale sharks consume plants, according to marine biologists, making the iconic animal the worlds biggest omnivore. Whale sharks are filter feeders, and in Western Australias Ningaloo Reef, they have long been seen taking in krill.
Australian Institute of Marine Science fish biologist Dr. Mark Meekan. Credit: Andre Rerekura, Australian Institute of Marine Science
Scientists found that whale sharks in the reef were taking in a lot of plant product when they examined biopsy samples from the animals.
” This causes us to reconsider whatever we believed we knew about what whale sharks consume,” said Australian Institute of Marine Science fish biologist Dr. Mark Meekan. “And, in truth, what theyre doing out in the open ocean.”
The discovery makes whale sharks, which have been determined up to 18.8 meters (61.7 feet) in length, the most significant omnivores in the whole world.
” On land, all the most significant animals have actually always been herbivores,” Dr. Meekan stated.
” In the sea, we always believed the animals that have gotten truly big, like whales and whale sharks, were feeding one action up the food chain on small fishes and shrimp-like animals. Turns out that perhaps the system of advancement on land and in the water isnt that different after all.”
Australian researchers analyzed whale shark tissue to analyze what they were using for energy and growth. Credit: Andre Rerekura, Australian Institute of Marine Science.
The study was just recently released in the journal Ecology. The researchers collected samples of prospective food sources at the reef, varying in size from little plankton to giant seaweed, in order to determine exactly what the whale sharks were taking in. Then they compared the amino and fats in the whale sharks to those in the plankton and plant product.
Dr. Meekan said that compounds discovered in Sargassum, a form of brown seaweed typical to Ningaloo that breaks off the reef and drifts at the surface area, existed in the whale shark tissue.
” We think that over evolutionary time, whale sharks have evolved the ability to digest some of this Sargassum thats entering into their guts,” he stated.
” So, the vision we have of whale sharks coming to Ningaloo just to delight in these little krill is just half the story. Theyre in fact out there eating a fair quantity of algae too.”
Scientist discovered whale sharks consumed plants in addition to krill. Credit: Andre Rerekura, Australian Institute of Marine Science
CSIRO Oceans and Atmosphere organic biogeochemist Dr. Andy Revill, who evaluated the whale shark tissue utilizing compound-specific steady isotope analysis, said the technology permitted researchers to study what animals were used for energy and development, not simply what they were consuming.
” Something like a whale shark, which swims through the water with its mouth open, is going to ingest a great deal of various things,” he said.
” But you do not understand just how much of that has actually been used by the animal and how much just goes straight out the other end. Whereas stable isotopes, because theyre really incorporated into the body, are a much better reflection of what the animals are really utilizing to grow.”
Biological oceanographer Dr. Patti Virtue, from the University of Tasmanias Institute for Marine and Antarctic Studies, said she was surprised by the whale sharks biochemical signature.
” Its very strange since in their tissue they dont have a fat or steady isotope signature of a krill-feeding animal,” she said.
The scientists also caught whale shark poo with a net and examined it.
” The poo did show that they were eating krill,” Dr. Virtue said. “But theyre not metabolizing much of it.”
Referral: “The worlds biggest omnivore is a fish” by M. G. Meekan, P. Virtue, L. Marcus, K. D. Clements, P. D. Nichols and A. T. Revill, 19 July 2022, Ecology.DOI: 10.1002/ ecy.3818.
This AIMS whale shark research study task is supported by Santos and INPEX as Joint Venture individuals in the Van Gogh Development.