Great white sharks (Carcharodon carcharias) are sometimes imagined looking giant prey. However apparently they spend extra of their time — not less than as juveniles — nosing round on the seafloor for little morsels of meals.
Between 2008 and 2019, researchers studied the abdomen contents of 40 juvenile nice white sharks captured off the coast of jap Australia. That info, mixed with information from research elsewhere on the earth, painted a stunning image of how these younger sharks feed. The sharks’ principal meals was a big fish: Australian salmon (Arripis trutta), representing about one-third of what they ate. However greater than a fifth of their weight loss program was made up of critters that swim simply above the ocean backside, reside in reefs, or bury themselves within the sand.
Associated: Image gallery: great white sharks
This is a breakdown of the shark diets, based on the paper, which was printed June 7 within the journal Frontiers in Marine Science:
- Mid-water swimming fish, like Australian salmon: 32.2%
- Backside-dwelling fish, reminiscent of stargazers, sole or flathead: 17.4%
- Reef fish, reminiscent of jap blue gropers: 5.0%
- “Batoid” fish, a gaggle of flat-bodied fish like stingrays: 14.9%
- Unidentified or uncommon prey: 30.5%
“This evidence matches data we have from tagging white sharks [with electronic trackers] that shows them spending a lot of time many meters below the surface,” Richard Grainger, lead writer of the examine and a researcher on the College of Sydney, said in a statement. “The hunting of bigger prey, including other sharks and marine mammals such as dolphin, is not likely to happen until the sharks reach about 2.2 meters [7.2 feet] in length,” Grainger mentioned.
There was additionally some proof that the male sharks went after stingrays and their cousins extra typically than feminine sharks did; however the researchers famous that there was a reasonably small pattern dimension from which to make this declare.
Nice white sharks are well-understood in contrast with different shark species, mentioned Catherine Macdonald, director of the Subject Faculty (a marine biology schooling program) and a conservation biologist on the College of Miami in Florida, who was not concerned within the new examine.
However there’s nonetheless loads to find out about how white sharks behave.
“These results align well with what scientists know about white shark diet and how target prey species change as individual sharks increase in size,” Macdonald informed Reside Science. “From a scientific perspective, that’s great news, because it helps confirm the results of previous studies done using different techniques, and suggests we already have a pretty good general picture of white shark diet at different life stages.”
It is essential to know that these outcomes signify a snapshot of how these sharks lived in a selected place and time, Macdonald added. Sharks eat many issues, and it is possible that their selections are always in flux because the world round them adjustments. These predators possible instinctively weigh components like their threat of damage or encountering one other predator, their odds of catching the prey, how nutritious the prey is and the way hungry they’re in selecting what to hunt, she mentioned.
“Humans are having unprecedented impacts on marine ecosystems, and so what [they are] measuring isn’t really ‘what white sharks eat’ — it’s ‘what white sharks are currently eating based on all of the effects human actions have already had on their ecosystems,'” she mentioned. “The paper identifies eastern Australian salmon (A. trutta) as an important food item — but fishing pressure, changes in ocean temperature and availability of their prey means that populations of A. trutta look quite different today than they have historically.”
Initially printed on Live Science.