VIDEO SHOWN AT LINK BELOW ARTICLE
Kelly Hearn
for National Geographic News
November 24, 2008
A mile and a half (two and a half kilometers) underwater, a remote control submersible's camera has captured an eerie surprise: an alien-like, long-armed, and—strangest of all—"elbowed" Magnapinna squid. (See photos of Magnapinna.)
In a brief video from the dive recently obtained by National Geographic News, one of the rarely seen squid loiters above the seafloor in the Gulf of Mexico on November 11, 2007.
The clip—from a Shell oil company ROV (remotely operated vehicle)—arrived after a long, circuitous trip through oil-industry in-boxes and other email accounts.
"Perdido ROV Visitor, What Is It?" the email's subject line read—Perdido being the name of a Shell-owned drilling site. Located about 200 miles (320 kilometers) off Houston, Texas (Gulf of Mexico map), Perdido is one of the world's deepest oil and gas developments.
The video clip shows the screen of the ROV's guidance monitor framed with pulsing inputs of time and positioning data.
In a few seconds of jerky camerawork, the squid appears with its huge fins waving like elephant ears and its remarkable arms and tentacles trailing from elbow-like appendages.
Despite the squid's apparent unflappability on camera, Magnapinna, or "big fin," squid remain largely a mystery to science.
ROVs have filmed Magnapinna squid a dozen or so times in the Gulf and the Pacific, Atlantic, and Indian Oceans.
The recent video marks the first sighting of a Magnapinna at an oil development, though experts don't think the squid's presence there has any special scientific significance.
But the video is evidence of how, as oil- and gas-industry ROVs dive deeper and stay down longer, they are yielding valuable footage of deep-sea animals.
Some marine biologists have even formed formal partnerships with oil companies, allowing scientists to share camera time on the corporate ROVs—though critics worry about possible conflicts of interest.
The Perdido squid may look like a science fiction movie monster, but it's no special effect, according to squid biologist Michael Vecchione of the U.S. National Oceanic and Atmospheric Administration (NOAA), who is based at the National Museum of Natural History in Washington, D.C.
In 1998 Vecchoine and University of Hawaii biologist Richard Young became the first to document a Magnapinna, based on juveniles of the Magnapinna pacifica species. M. pacifica was so unusual that the scientists had to create a new classification category to accommodate it: the family Magnapinnidae, which currently boasts four species.
In 2001 the pair released the first scientific report based on adult Magnapinna specimens, as seen via video. The study demonstrated that Magnapinna are common worldwide in the permanently dark zone of the ocean below about 4,000 feet (1,219 meters).
(See "'Weird' New Squid Species Discovered in Deep Sea" [December 20, 2001].)
In 2006 a single damaged specimen from the North Atlantic led to the naming of a second Magnapinna species, M. talismani. And in 2007 the scientists documented two more: M. atlantica and a species based on a specimen from the mid-Atlantic.
That fourth Magnapinna species remains nameless, because its arms were too badly damaged for a full study. "However, it was clearly different from the three known species," Vecchione said.
The Magnapinna species apparently have only slight physical differences, mainly related to tentacle and arm structure in juveniles.
The subtlety of those variations makes it impossible to identify which species is in the oil-rig video, given that at least two Magnapinna species—M. atlantica and M. pacifica—are known to inhabit the Gulf of Mexico, Vecchione said.
Enduring Mystery
Based on analysis of videos not unlike the one captured at the Perdido site, scientists know that the adult Magnapinna observed to date range from 5 to 23 feet (1.5 to 7 meters) long, Vecchione said. By contrast, the largest known giant squid measured about 16 meters (52 feet) long.
And whereas giant squid and other cephalopods have eight short arms and two long tentacles, Magnapinna has ten indistinguishable appendages that all appear to be the same length.
"The most peculiar structure is that of the arms," said deep-sea biologist Bruce Robison of the Monterey Bay Aquarium Research Institute in California.
Referring to the way the tentacles hang down from elbow-like kinks, Robison said: "Judging from that structure, we think the animal feeds by dragging its arms and the ends of its tentacles along the seafloor as it drifts slowly above it."
The elbow-like angles allow the tentacles to spread out, perhaps preventing them from getting tangled.
"Imagine spreading the fingers of a hand and dragging the fingertips along the top of a table to grab bits of food," he added.
But NOAA's Vecchione suggests a feeding behavior that is more like trapping than hunting. He speculates that Magnapinna passively waits for prey to bump into the sticky appendages.
http://news.nationalgeographic.com/n...agnapinna.html
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