This rare video published on January 13 shows a deep-sea squid (Gonatus onyx) fighting to eat what appears to be a larger owlfish (Pseudobathylagus milleri). The video was made with the remotely operated vehicle Doc Ricketts, by the Monterey Bay Aquarium Research Institute (MBARI).
The squid, also called the clawed armhook squid or black-eyed squid, lives in the northern Pacific Ocean from Japan to California. It is thought to grow to a mantle length of 7 inches (18 centimeters). (In squid, all the part of the body behind the head is the mantle, including the fins.)
The squid is an active predator that patrols the depths for fish and shrimp.
The owlfish Pseudobathylagus milleri, also called the stout blacksmelt, also lives in the deep waters of the north Pacific Ocean, to depths of 21,700 feet (6,600 meters). The fish grows to a length of 6.5 inches (16.5 centimeters) and feeds on small crustaceans and jellies. They have giant eyes to help them find food in the dim light of the depths.
According to news reports, the Doc Ricketts discovered the writhing animals at about 1,475 feet (450 meters) below California’s Monterey Bay, as the vehicle was rising toward the surface. Scientists controlling the vehicle watched the battle for about 50 minutes.
The squid struggled with the fish in its grasp, until it could successfully cut through the animal’s spinal cord with its sharp beak, said Bruce Robison, a senior scientist at MBARI who narrates video of the fight.
“These remarkable images show a struggle for survival never before seen by human observers,” Robison said.
He added that owlfish defend themselves against such attacks by sloughing off scales and then darting away when they first feel the touch of a squid tentacle. That doesn’t always work, however.
The Doc Ricketts remotely operated vehicle (ROV) is operated from MBARI’s SWATH research vessel, the R/V Western Flyer. The ROV sports high definition video cameras and a number of sensors and data loggers. It is named after pioneering marine biologist Ed Ricketts (1897-1948), who published widely on the intertidal zone and inspired writing by his friend John Steinbeck.