923733794

923733794

Epaulette shark (Hemiscyllium ocellatum). Marine fish.

Photo by: wrangel

wrangel

New Year, New Walking Sharks?

By: Leah Weber

A shark that walks, evolutionary conundrums, temperature changes, and tectonic shifts lead scientists to discover four new species of sharks.

January 24, 2020

It is a happy new year for a group of scientists from across the world who have discovered four new species of sharks! And these new species of tropical sharks use their muscular fins to “walk” and forage for small fish in shallow reefs and sea grass.

“2020 is already off to a great start thanks to the discovery of four new shark species in one paper!” says marine biologist Vicky Vásquez. “When it comes to outreach, walking catsharks play double duty as representatives for the diversity in shark morphology as well as the importance of coral reef ecosystems.”

1011944232

1011944232

A juvenile endemic Raja Epaulette shark, Hemiscyllum freycineti, walks on the sandy seafloor in Raja Ampat, Indonesia. This small elasmobranch is known as a 'walking shark' due to its behaviors.

Photo by: Velvetfish

Velvetfish

A juvenile endemic Raja Epaulette shark, Hemiscyllum freycineti, walks on the sandy seafloor in Raja Ampat, Indonesia. This small elasmobranch is known as a 'walking shark' due to its behaviors.

Published in Marine and Freshwater Research is the twelve-year study of the genus Hemiscyllium and their very recent evolution, around 9 million years ago. To give it context, sharks are very old, with some form of this tough fish being on the planet as long as 450 million years ago. This makes them nearly twice the age of the oldest dinosaur fossil ever found. It is pretty special that this small shark has shown signs of evolution in only two percent of that time.

953049726

953049726

Hemiscyllium halmahera, close up shot during night dive.

Photo by: Akkarachai Ditjanapongpon

Akkarachai Ditjanapongpon

Hemiscyllium halmahera, close up shot during night dive.

The reason for the genetic change? The evolution of the walking shark from five species to nine was likely caused by the species being separated by different geographical factors over the course of millions of years. The behaviors of walking sharks are partially driven by changing sea levels and shifting landscapes (i.e. moving tectonic plates). Once sea levels rose and remperatures dropped, these walking sharks were pushed to migrate to warmer waters.

But this study is only the beginning, and it’s thought that these findings could spawn more research leading to the discovery of even more species.

Next Up

The T-Rex Has a New Branch on its Family Tree

A farmer happened upon one of the greatest fossil finds in Canada, which was recently announced by paleontologists to be, quite possibly, one of the oldest dino-finds in the country!

Man Vs Bear is a New Competition Show on Discovery & It’s Like Nothing You’ve Seen Before

For the first time ever, humans will enter the grizzly bear’s domain to test their strength, speed, and stamina against nature’s top predator.

Cows Kill More People Than Sharks

Sharks are the least of your problems according to these statistics.

99 Percent Of The Earth's Species Are Extinct—But That's Not The Worst Of It

There's been a vast diversity of life that has existed is now extinct.

How the World’s Largest Delta Might Slowly Go Under Water

The uneven rise of the sea impacts communities in South Asia

Some Male Cuttlefish 'Cross-Dress' to Woo the Ladies

Learn about cuttlefish at Discovery.com

70% Of Earth's Fresh Water Is Frozen

Our freshwater is locked up in the Antarctic Ice Sheet.

Would You Eat a Genetically Engineered Fish?

There's something fishy about the upcoming release of bioengineered salmon.

If Cicadas Come Out Once Every 17 Years, Why Do You See Them Every Summer?

These mysterious insects have one of the strangest life cycles in the natural world.

These Bee Chicas Are Colorado’s Local Heroes

Last year, US beekeepers lost almost 40% of their bee colonies. Four women banded together to help the bee population flourish in Colorado.