Science

Scientists identify first known 'vegetarian' shark

Scientists identify first known 'vegetarian' shark”

Scientists have now discovered that one of the most common sharks in the world is actually an omnivore.

Scientists at the University of California in Irvine, and Florida International University in Miami, made a decision to investigate the sharks' dietary habits after reading reports of the fish chomping on seagrass, the flowering marine plant that forms subsea meadows in some coastal waters.

Although co-authors Samantha Leigh, Yannis Papastamatiou, and Donovan German presented their findings on the shark's unusual seagrass-eating habits at the Society for Integrative and Comparative Biology's annual meeting in January, the newly published study states that this is the "first species of shark ever to be shown to have an omnivorous digestive strategy", the authors wrote. "We have never seen a shark consume this seagrass, let alone that's able to digest it". They also showed the fish digested the seagrass using enzymes that broke down the plants, like starch and cellulose, since their razor-sharp teeth aren't well suited for chewing. (Chris huh/Wikimedia Commons/CC BY-SA 3.0 [ept.ms/2Bw5evC])Back in 2007, other scientists found through studying the stomach contents of bonnethead sharks that, surprisingly, more than half of what they'd eaten was seagrass.

"We have always thought of sharks as strict carnivores, but the bonnethead is throwing a wrench into that idea by digesting a fair amount of the seagrass that they consume".

Sharks are supposed to be the quintessential carnivores, with stomachs specially designed for digesting high-protein foods; they're built to eat meat and nothing else.

The bonnethead shark is commonly found in the shallow waters of the Western Atlantic, Eastern Pacific, and the Gulf of Mexico.

Seagrass meadows, the scientists say, represent the most widespread coastal ecosystem on the planet, providing many important ecological and food-based services. They thought the sharks must have picked up some grass as it nabbed a meaty crab.

The sharks also absorbed nutrients from the seagrass and even gained weight on the diet, Leigh and team report today in the journal Proceedings of the Royal Society B.

While most sharks crave fresh meat, the bonnethead shark, which is a relative of the iconic hammerhead, is actually just fine with salad. At the end of the three-week testing period, the team analyzed the sharks' fecal matter and digestive systems, ultimately concluding that the bonnetheads did, in fact, digest and absorb nutrients offered by the seagrass. "However, the bonnethead shark had very high levels of these types of enzymes!" Their great numbers will force researchers to re-evaluate the role that bonnetheads play in seagrass meadows, which are critical ecosystems that provide habitat for thousands of fish species, filter the surrounding water, act as a sink for atmospheric CO2, and produce large quantities of oxygen.



Like this

loading...
loading...

Latest


07 September 2018
Plane with sick passengers quarantined at JFK
Numerous healthy passengers described hearing fellow travelers violently coughing during the flight. Phillips said earlier the flight had stopped in Mecca, which is experiencing a flu outbreak.

07 September 2018
College Announces It Is Dropping Nike Gear After Colin Kaepernick Decision
The school even went so far as to say that it would forfeit any competition if a player from the opposing team refused to stand for the anthem.

07 September 2018
Republican reaction to New York Times op-ed: Some concern, some shrugs
The writer of the piece says he or she wants Americans to know that "there are adults in the room". Dao said: "I feel that we followed a definition that has been used by our newsroom in the past".

07 September 2018
India and U.S. sign military deal amid tensions over Iran sanctions
New Delhi , one of the biggest buyers of Iranian crude, will have to find measures to nullify the effect of USA sanctions on Iran. The two sides also discussed key issues, including cross-border terrorism, India's NSG bid and the contentious H-1B visa issue.

07 September 2018
McCain honored at funeral by Bush and Obama
Ivanka Trump , President Donald Trump's daughter, and her husband, presidential adviser Jared Kushner , were surprise guests. Naval Academy within view of the Severn River and earshot of midshipmen present and future, and alongside a lifelong friend.

06 September 2018
Five things we learned from the Premier League
Both teams are equal top of the Premier League alongside Watford . "Against [for example] Man City, I know it will be hard ", answered Hazard, when asked about the style of football.

06 September 2018
Pediatric experts call for flu shots over AstraZeneca's nasal vaccine this year
That said, parents who have concerns about allergies or possible reactions to the shot should talk with their doctors, she said. The nasal spray that protects against the flu is only recommended for people ages 2 to 49 who are not pregnant.

06 September 2018
What A New NAFTA Deal Might Mean For The Auto Industry
The updated deal between Mexico and the U.S. includes new clauses on intellectual property, digital trade and investor disputes. But on the sidelines, President Trump and Prime Minister Justin Trudeau have dug into seemingly irreconcilable positions.

06 September 2018
TMZ: Burt Reynolds has died at 82
Reynolds was also a college football player at Florida State and shared a room with ESPN's Lee Corso. Burt Reynolds has died at the age of 82, according to The Hollywood Reporter .

06 September 2018
Kanye apologizes to Drake for "Jedi level" feud
The track not only outed the fact that Drake had a secret child but sparked controversy for the Toronto rapper; the cover art was an old photo of Drake in blackface. "He said what he said, I said what I said, now it's done".