Researchers at UC Irvine identified the first omnivorous shark after a four-year study.
The bonnethead shark has been known to eat plants like seagrass, but many scientists initially thought it was by accident.
Samantha Leigh led a study with UCI’s Department of Ecology and Evolutionary Biology to learn more.
In their lab, five sharks were given Florida Bay seagrass and a small side of squid.
Leigh and researchers found the sharks obtained more than half of the seagrass’ organic matter, meaning they were well nourished.
“Sharks have gotten such a bad reputation as really ravenous meat-eaters,” Leigh said. “We’ve shown that there is at least one type that also consumes plant materials. There is so much more to discover about them.”
The major breakthrough is not that a species of shark eats vegetation, but that bonnetheads can live off of a diet consisting mainly of plants, according to UCI’s researchers.
The team found bonnetheads have higher levels of enzymes that can break down fibers and carbohydrates that are normally found in carnivores.
But with this discovery comes another important one.
“[Seagrasses] produce oxygen, screen toxins, and provide species nursing habitats,” Leigh said. “The fact a highly abundant kind of shark feeds on the grasses is yet another indication of why we need to preserve this vegetation.”
Bonnetheads also eat crabs and other crustaceans and some fish.
The bonnethead shark is mainly found along U.S. coastlines.