Photos: Rare Deep-Sea Anglerfish Recorded

Red Fish, Blue Fish

Image courtesy MBARI

The first live observations of anglerfish in their natural habitat revealed that not all of them are red or rose-colored, as previously thought.

"One of the things we noticed right off the bat is all the larger ones are red and the smaller ones tend to be blue," MBARI's Lundsten said. "So we think ... that it's changing color, from a bluish-transparent larval phase to a red adult form."

The largest specimen that Lundsten's team observed was about 8 inches (20 centimeters) long, while the smallest was about 3 inches (7 centimeters) long.

The purplish color of the anglerfish pictured above suggests it is an adolescent, Lundsten added.

Another surprise from the imagery Lundsten's team collected: The fish appear able to "walk" along the seafloor using a combination of their pectoral fins and pelvic fins.

Scientists speculate that “walking” is more energy efficient than swimming short distances, and that it also disturbs the surrounding seawater less, reducing the chances of startling nearby prey.

(See a video clip from MBARI.)

Published August 23, 2012

Strong Swimmer

Image courtesy MBARI

Yellow sediments cling to the fins of an adult deep-sea anglerfish photographed swimming near the Taney Seamounts, off California’s Central Coast at a depth of about 8,530 feet (2,600 feet).

C. coloratus was first described from a single dead specimen, which was collected at the Cocos Ridge in the Pacific Ocean near Costa Rica in 1891, but it had never been seen alive by scientists.

That changed in 2002, when the remotely operated vehicle (ROV) Tiburon stumbled upon the species near Davidson Seamount, also off the coast of California.

(Related: “Pictures: Odd Sea Creatures Found at Volcanoes, Canyons.”)

In 2010, the team observed six more of the rare fish during ROV dives at Taney Seamounts.

The ROV footage revealed that C. coloratus can live at depths of up to 11,000 feet (3,353 meters)—nearly twice as deep as previously thought.

(More about deep-sea exploration: “James Cameron Completes Record-Breaking Mariana Trench Dive.”)

Published August 23, 2012

Waiting for Prey

Image courtesy NOAA/MBARI

A deep-sea anglerfish hides among rocks as it waits to ambush curious fish. On its head is a piece of dangling flesh—called an "esca"—that functions as a lure for prey.

"They're ambush predators," MBARI's Lundsten explained. "If something comes by, they'll open up their huge mouths and swallow up whatever it is."

(See more ocean-species hunting tricks: “Photo Gallery: Masters of Undersea Camouflage.”)

During one ROV dive, the researchers observed an anglerfish stowing its fishing gear away in a special cavity located between its eyes.

Lundsten and his team suspect that C. coloratus's lure glows in the dark to better attract prey, but this has not been confirmed.

"We didn't observe any bioluminescence [in the ROV video] ... but we assume that it probably does," he said.

Published August 23, 2012

Next Gallery: Strange Sea Species Found Off Greenland

Photograph courtesy Julius Nielsen, Greenland Institute of Natural Resources

Published August 23, 2012