Sharks' Road to Being Vegetarians? Scientists Still Can't Say For Sure

Khryss | Published 2017-07-02 01:06
A predator near the top of marine food chains with sharp teeth, incredibly fast movement and a very keen sense of smell to detect blood that's even miles away--sharks are the very reason why most people are afraid of the oceans' depth. But who would've thought they can also be a fan of greens and eat a large amount of seagrass? Don't believe me? See for yourself. Bonnethead sharks love seagrass so much that it makes up 56% of their diet! That's similar to young sea turtles--a big deviance to the well-known carnivorous big fishes! Related to the more familiar hammerhead, these shovel-headed sharks just show how little we still know about marine life. Samantha Leigh, a Ph.D. candidate at the University of California, Irvine and a National Geographic explorer said that though uncertain, this could be incidental as grasses go when they munch on other preys. “Even if it is incidental, it is a very large amount of grass, so they have to be able to process that somehow,” said Leigh. “It’s very likely they have some sort of microbiome living in their gut that is producing some of the enzymes that they need to break down this plant material, which is something we commonly find in omnivorous and especially herbivorous species,” she said. However, they still can't be dubbed omnivores due to the uncertainty on whether or not such habit is purposeful and that they specifically use plants for certain nutritional value. Younger bonnethead sharks were even found to eat more seagrass than adults; a possible learning curve (eating their prey without incidentally munching on seagrass as well) as they grow up, said Dana Bethea, a research ecologist with NOAA Fisheries in Florida. “There’s a lot of prey handling learning that goes on in the younger life stages until they get to be bigger and really get their mouths around what they’re feeding,” she said. “That’s how we think they get the plant material in their stomachs. We don’t think they’re out there eating salad.” Nonetheless, ocean's still really full of surprises, don't you think?
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