Mesoplodon traversii

Rarest whale seen at last in New Zealand

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Picture of a rare spade-toothed whale
An exceedingly rare spade-toothed whale, live-stranded on a New Zealand beach. Credit: New Zealand Govt.

mesoplodon traversii map
Localities and dates of the known Mesoplodon traversii specimens Credit: Dysmorodrepanis

Info from Scientific American:

"Until now, we’ve only known about the spade-toothed beaked whale from a few bone samples, as no intact specimens have been discovered. This has made identifying the species extremely complicated. In 1872, a partially damaged mandible and set of teeth were picked up on Pitt Island, of the Chatham Island archipelago in New Zealand, and described by the director of the Colonial Museum of New Zealand at the time, James Hector, the following year. As no one had ever seen a spade-toothed whale before, Hector assigned the bones to the Scamperdown whale (Dolichodon layardii), which had been discovered eight years prior by British zoologist John Edward Gray. This species was the most commonly beached beaked whale around the New Zealand coast at the time.

"Gray caught wind of this and examined the bones himself, and in 1874 assigned them to an entirely new species, which he called Dolichodon traversii. The correct genus was a point of contention for these whales, so Dolichodon traversii was later corrected to Mesoplodon traversii. In response to Hector’s analysis, and explaining the need to name a new species, Gray noted that, “‘Mesoplodon layardi (or as I should call it, Dolichodon layardi) has a much longer and attenuated lower jaw, and much more slender teeth than the Chatham Island specimen”, in Transactions of the New Zealand Institute (PDF)."
Updated Feb. 17, 2014 — A whale almost unknown to science has been seen alive for the first time after two individuals — a mother and her male calf — were stranded and died on a New Zealand beach. A report in the journal Current Biology, offers the first complete description of the spade-toothed beaked whale (Mesoplodon traversii), previously known only from a few bones.

The discovery is the first evidence that this whale is still with us and serves as a reminder of just how little we still know about life in the ocean, the researchers say. The findings also highlight the importance of DNA typing and reference collections for the identification of rare organisms.

Editor's note: Extremely rare organisms, for which only one or a few specimens are known, often turn out to be hybrids.
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"This is the first time this species — a whale over five meters in length — has ever been seen as a complete specimen, and we were lucky enough to find two of them," says Rochelle Constantine of the University of Auckland. "Up until now, all we have known about the spade-toothed beaked whale was from three partial skulls collected from New Zealand and Chile over a 140-year period. It is remarkable that we know almost nothing about such a large mammal."

The two whales were discovered in December 2010, when they live-stranded and subsequently died on Opape Beach, New Zealand. The New Zealand Department of Conservation was called to the scene, where they photographed the animals and collected measurements and tissue samples.

The whales were initially identified not as spade-toothed beaked whales but as much more common Gray's beaked whales. Their true identity came to light only following DNA analysis, which is done routinely as part of a 20-year program to collect data on the beaked whales found in New Zealand waters.

"When these specimens came to our lab, we extracted the DNA as we usually do for samples like these, and we were very surprised to find that they were spade-toothed beaked whales," Constantine says. "We ran the samples a few times to make sure before we told everyone."

The researchers say they really have no idea why the whales have remained so elusive.

"It may be that they are simply an offshore species that lives and dies in the deep ocean waters and only rarely wash ashore," Constantine says. "New Zealand is surrounded by massive oceans. There is a lot of marine life that remains unknown to us."

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Adapted from materials obtained from the AAAS









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