A creature that marine biologists consider “one of the world’s rarest” creatures has been spotted off the coast of Papua New Guinea for the first time in 31 years and the third time ever.
Marine biologists believe that the elusive species, Allonautilus scrobiculatus, is about 500 million years old. The species has lived in the seas before the dinosaurs and survived the last two Ice Ages.
Before the latest sighting, the rare marine species, closely related to squids and cuttlefish, had been seen by only two people in the world. The first person was Bruce Saunders from Bryn Mawr College in 1984. The second person was Peter Ward, professor of biology at the University of Washington, who spotted the creature off the coast of Papua New Guinea a few weeks after Saunders reported the first sighting.
Saunders had a second brief encounter with Allonautilus in 1986, according to UW Today.
Marine biologists have nicknamed Allonautilus “living fossils” because of their great age and distinctive shells that marine biologists first encountered as fossils.
“Some features of the nautilus — like the shell giving it the ‘living fossil’ label — may not have changed for a long time, but other parts have. It has this thick, hairy, slimy covering on its shell. When we first saw that, we were astounded.”
In the effort to lure the creature so that it can be filmed, the researchers set up — at depths between 500 and 1,300 feet — baits consisting of fish and chicken flesh suspended on poles, and filmed activity around the bait 12 hours daily.
According to Ward, “We started using this approach in 2011. This year, there were about 30 guys involved and each day we would all watch the movies from the night before at 8X speed. There were a lot of ‘ohs’ and ‘ahs.'”
The painstaking effort of the biologists finally yielded result in July when two of the creatures came to inspect the pole. The biologists were able to record footage showing two Allonautilus individuals who approached the bait and fought for the food before a sunfish appeared.
“It has this thick, hairy, slimy covering on its shell. When we first saw that, we were astounded.”
They trapped several individuals at a depth of about 600 feet and obtained from the specimens samples of tissue, shell, and mucous. They released them back into the water after collecting the samples.
So far, sightings of Allonautilus have occurred exclusively off the coast of Papua New Guinea. But Ward says that search for the species will continue in other parts of the world.
“It’s only near this tiny island. This could be the rarest animal in the world. We need to know if Allonautilus is anywhere else, and we won’t know until we go out there and look,” he said.
The distribution of the species in the world’s oceans is limited by the fact that they are able to survive only under specific marine environmental conditions.
Allonautilus swim close to the bottom of the sea but cannot survive below 2,500 meters depth. They also avoid surface waters because they do not thrive in excessively warm water.
According to Ward, despite having survived in the oceans for 500 million years, Allonautilus are now threatened by extinction due to human activity, including mining and illegal fishing.
[Images: UW Today/Peter Ward]