After nearly a decade long effort, scientists have finally managed to photograph the elusive Omura whale (Balaenoptera omurai). Prior to this, the near-mythical creature has only been known through deceased remains. There have been 44 live observations of the whale.
“Over the years, there have been a small handful of possible sightings of Omura’s whales, but nothing that was confirmed,” said lead author Salvatore Cerchio, a marine mammal biologist with the Wildlife Conservation Society. “They appear to occur in remote regions and are difficult to find at sea, because they are small and do not put up a prominent blow.”
At long last, scientists have been able to shed some light on the habits and biology of the mysterious Omura whale.
The Omura whale was first discovered in the 1970s when scientists realized eight carcasses killed by Japanese whalers were different from known whale species. Caught in the eastern Indian Ocean as well as the western Pacific Ocean, the whales were initially thought to be pygmy Bryde’s whales. The Omura are typically 33 to 38 feet long; a Bryde’s whale (Balaenoptera edeni) is about 45 feet long. It wasn’t until 2003 that DNA evidence proved the two species were distinct.
Since that time, scientists have used DNA and skeletal evidence to identify the remains of several other whales corpses.
While searching for the Omura, the scientists initially made the same mistake.
“At first, we thought they were Bryde’s whales, an understandable mistake because of the similar size and habitat,” said Cerchio. “But then with good photographs and underwater video, we noticed they more closely resembled the description of Omura’s whales.”
An international team of marine biologists set out to scour the seas in hopes of capturing the Omura with underwater cameras. Eventually, the Omura were found to be living near the island of Madagascar.
“The only problem was that Omura’s whales were not supposed to be in this part of the Indian Ocean. Rather, they should be in the west Pacific, near Thailand and the Philippines,” said Cerchio.
Skin biopsies were needed to confirm the DNA was of the Omura whale. Indeed, it was a match.
The Omura is shaped like a torpedo and has peculiar markings. They travel alone or in pairs. Sometimes, they also travel in what is known as ‘loose aggregations’, that is, as many as six whales travel together but remain several hundred feet apart. The whales ate mostly zooplankton. They commincate using incredibly low-frequency vocalizations.
“When we clearly saw that the right jaw was white, and the left jaw was black, we knew that we were on to something very special,” said Cerchio.
Over the course of a five-year expedition, the team identified 25 individual whales, including four mothers with calves. The scientists are not sure if the Omura live near Madagascar year-round or if the site is some sort of breeding ground.
The team intends to continue studying the Omura whales. The species is considered highly endangered.
The study was recently published in the prestigious journal Royal Society Open Science.