Shark Swallows Another Shark Whole

[Christiana Hanaman]

Shark Swallows Another Shark Whole



Munching on Bamboo (Shark)

Photograph courtesy Tom Mannering

A shark has been caught on camera making a meal of another shark along Australia's Great Barrier Reef. Released earlier this month, the pictures show a tasseled wobbegong halfway through swallowing a brownbanded bamboo shark.

Daniela Ceccarelli and David Williamson, from Australian Research Council's Centre of Excellence for Coral Reef Studies, chanced on the spectacle while conducting a fish census on the fringing reef off Great Keppel Island.

"The first thing that caught my eye was the almost translucent white of the bamboo shark," Ceccarelli said in an email. Expecting to find the front part of the bamboo shark hidden under a coral ledge, Ceccarelli swam closer—and the highly camouflaged wobbegong materialized.

"It became clear that the head of the bamboo shark was hidden in its mouth," she said. "The bamboo shark was motionless and definitely dead." (Also see shark pictures by National Geographic fans.)

Previous analyses of the shark species' stomach contents had shown that wobbegongs do eat other sharks. (Related pictures: "Sharks Taught to Hunt Alien Lionfish.")

"I doubt that this is the first time such a thing has been seen," said Ceccarelli, who added that she does think this is the first published photograph of a wobbegong swallowing another shark.

—Helen Scales

Published February 13, 2012

http://news.nationalgeographic.com/news/2012/02/pictures/120213-sharks-swallows-whole-great-barrier-reef-animals-science/

[Christiana Hanaman]

Even Match

Photograph courtesy Tom Mannering

The wobbegong sits with the dead bamboo shark in its mouth along Australia's Great Barrier Reef.

Both species of predator and prey involved in this rarely witnessed episode grow to similar sizes—approximately 39 to 59 inches (100 to 125 centimeters) from head to tail. The two sharks also share much of their ranges in the western Pacific, where they hang out on the seabed around coral reefs.

"In areas where wobbegongs are common, their paths are [indeed] likely to cross," Ceccarelli said. "Bamboo sharks forage along the bottom, often poking their heads in holes and under ledges and overhangs to feed primarily on [bottom dwelling] invertebrates."

According to the online fish encyclopedia Fishbase, brownbanded bamboo sharks are also often spotted in tide pools and can survive for 12 hours out of water.

(Also see "Shark Ate Amphibian Ate Fish: First 'Food-Chain Fossil.'")

Published February 13, 2012

[Christiana Hanaman]

Carpet Shark

Photograph by Reinhard Dirscherl, Alamy

With their flat bodies and fringed faces, it's probably no surprise that tasseled wobbegongs—like this one in waters off Indonesia—are also known as carpet sharks.

"They lie on the seabed, camouflaged against the bottom, waiting motionlessly for potential prey to swim past and then attack at lightning speed," Ceccarelli said.

As opportunistic ambush predators, wobbegongs are "unlikely to be picky about what they prey on," she added. That helps explain why the Australian wobbegong was able to make a meal of a shark almost as big as itself. (Related picture: "Python Bursts After Eating Gator.")

As with many sharks, the wobbegong's jaws dislocate, helping them to engulf large prey, and their teeth point backward so they can keep a grip on their meals.

"With enough time, they can dismember and consume prey even larger than themselves," Ceccarelli said.

Published February 13, 2012

[Christiana Hanaman]

Shaggy Shark

Photograph by Ethan Daniels, Alamy

A tasseled wobbegong blends into its surroundings, assisted by reticular markings and intricate skin flaps that break up the outline of its flattened body.

Even though it's easy enough for a wobbegong to devour a big meal, scientists are unsure how the animal manages to process prey as large as other sharks. (Also see "Sharks Eating Songbirds in Gulf of Mexico.")

"There's been very little work done to establish exactly how wobbegongs digest their prey," Ceccarelli said. "Most sharks swallow their prey whole, so with a mouthful like [a whole other shark], digestion could take several days."

A study of the shark-eats-shark observation appears in the current issue of the journal Coral Reefs.

Published February 13, 2012

[Christiana Hanaman]

http://news.nationalgeographic.com/news/2012/02/pictures/120213-sharks-swallows-whole-great-barrier-reef-animals-science/#/carpet-shark-swallows-bamboo-shark-setting_48652_600x450.jpg