Deep sea thrill: 'serpent' of myths filmed

GEORGINA ROBINSON
February 9, 2010

Scientists have caught what could be the first deep-sea glimpse of the world's longest and rarest "serpent" fish.

The long, thin, metallic silver oarfish - which can grow to 17 metres and is believed to be the source of sea serpent myths - is usually only seen dying on the ocean's surface or dead, washed up on the shore.

But scientists working in collaboration with energy companies in the Gulf of Mexico have just filmed the rare oarfish in its deep-sea habitat by using a remotely operated vehicle, the BBC reports.

"We saw this bright vertical shiny thing. I said, 'are they lowering more riser?' as it looked like they were lowering a huge [drilling] pipe," University of Louisiana scientist Mark Benfield said.

"We zoomed in a little bit and we said: 'That's not a riser, that's a fish!'

"As we approached it retreated downwards swimming tail first in a vertical orientation as the ROV followed."

Early estimates put the fish at between five and 10 metres long.

Professor Benfield's team in the Gulf of Mexico followed the oarfish for about five minutes.
"What was interesting about the fish was its swimming behaviour," he said.

"It moved by undulating its dorsal fin in waves that propelled it backwards at quite a good speed."

It could be the first time the oarfish has been filmed alive in the mesopelagic, or "twilight", layer of the ocean, he said.

The harmless oarfish is found in all tropical and temperate marine waters. It feeds on plankton and fish.

A 4.5-metre specimen was found about six metres off shore from City Beach in Perth in 2005.

An oarfish has a long dorsal fin that runs the length of its body and appears to ripple when swimming, but no tail fin, the Australian Museum says.

It also has tiny spines that stick out from the pelvic fin, which were originally believed to "row" in a circular motion to propel the fish, hence its name.

But it is now believed the fins are taste sensors rather than propellers.

See video at: http://www.smh.com.au/environment/conservation/deep-sea-thrill-serpent-of-myths-filmed-20100209-node.html