Scientists surveying the Gulf of Mexico have captured extraordinary video footage of an Oarfish swimming in deep water, making it probably the first observation of this gigantic fish in its natural habitat.
Reaching up to 17 metres in length and believed to be the source of sea serpent myths, the Oarfish, Regalecus glesne, is found in all temperate and tropical oceans.
Despite its wide distribution, almost all encounters to date have consisted of dead fish washed ashore or dying fish seen in surface waters of the oceans.
The video was captured during a survey undertaken as part of the Serpent (Scientific and Environmental ROV Partnership using Existing Industrial Technology) project, which is a collaboration between the oil and gas industry and the scientific community that provides access to remotely operated vehicles (ROVs) to survey the ocean depths.
According to Mark Benfield from the Louisiana State University, the metallic oarfish, estimated to be between five and ten metres long, was initially thought to be a drilling pipe (riser) being lowered into the water.
“We saw this bright vertical shiny thing, I said ‘are they lowering more riser?’ as it looked like they were lowering a huge pipe.”
“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.”
Professor Benfield said that the way the oarfish swam was interesting, as the fish “…moved by undulating its dorsal fin in waves that propelled it backwards at quite a good speed.”