Scientists Find Mystery Killer Whales off Cape Horn, Chile


A rare photo of Type D killer whales showing their blunt heads and tiny eyepatches. Credit: J.P. Sylvestre, South Georgia, 2011. Genetic samples the team collected will help determine whether this animal, with its distinctly different color pattern and body shape, is indeed new to science.

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In January 2019, an international team of scientists working off the tip of southern Chile got their first live look at what might be a new species of killer whale. Called Type D, the whales were previously known only from a beach stranding more than 60 years ago, fishermen’s stories, and tourist photographs.

Genetic samples the team collected will help determine whether this animal, with its distinctly different color pattern and body shape, is indeed new to science.

“We are very excited about the genetic analyses to come. Type D killer whales could be the largest undescribed animal left on the planet and a clear indication of how little we know about life in our oceans,” said Bob Pitman, a researcher from NOAA Fisheries’ Southwest Fisheries Science Center in La Jolla, California.

The team’s encounter with the distinctive whales came after they spent more than a week at anchor, waiting out the perpetual storms of Cape Horn off southern Chile. It was here that the scientists collected three biopsy samples—tiny bits of skin harmlessly taken from the whales with a crossbow dart—from a group of Type D killer whales.

Into the Laboratory

Unraveling the secrets of these unique killer whales has now moved from the blustery Southern Ocean to the laboratory, where NOAA scientists will analyze DNA from the skin samples. “These samples hold the key to determining whether this form of killer whale represents a distinct species,” said Pitman.

The first record of the unusual killer whales came in 1955, when 17 animals stranded on the coast of Paraparaumu, New Zealand. Compared to other killer whales, they had more rounded heads, a narrower and more pointed dorsal fin, and a tiny white eyepatch; no whales like this had ever been described before.

Initially, scientists speculated that the unique look might have been a genetic aberration only seen in those stranded whales. Then, in 2005, a French scientist showed Pitman photographs of odd-looking killer whales that had taken fish from commercial fishing lines near Crozet Island in the southern Indian Ocean. They had the same tiny eye patches and bulbous heads.

The location, a quarter of the way around the world from New Zealand, suggested that relatives of the stranded whales might in fact be widespread.

Burgeoning tourism in Antarctica has since produced wildlife photographs in unprecedented quality and quantity. To monitor the distribution, movements, and abundance of killer whales in Antarctic waters, Pitman and colleagues, including members of the International Association of Antarctica Tour Operators, began to collect killer whale images from the Southern Ocean…

Read Full Article; NOAA (03-07-2019)