Since 1872, only seven were ever seen: World's rarest whale goes under the surgeon's knife

New Zealand scientists have begun dissecting a spade-toothed whale, considered the rarest whale in the world, marking the first time researchers have been able to study a complete specimen. On Monday, a small group of scientists and cultural experts gathered around the near-perfectly preserved male spade-toothed whale, hoping to decode decades of mystery surrounding this elusive species.

The spade-toothed whale, Mesoplodon traversi, is the world's rarest whale. Since 1872, only seven specimens have been found, and none have ever been sighted alive at sea. Almost nothing is known about this species, making it one of the most poorly known large mammalian species of modern times.

The male spade-toothed whale beached in July near Taieri Mouth, in the southern province of Otago, New Zealand. It is perfectly preserved and represents a unique opportunity to study a deep-sea mammal that has never been seen alive. The whale, measuring five metres (16.4 feet) long, was winched off a beach in July and placed in a special freezer until now.

Whale expert Anton van Helden, who has studied beaked whales for 35 years and described them as "the most enigmatic group of large mammals on the planet," expressed his excitement about the discovery. "I can't tell you how extraordinary it is," he said, according to The Independent. "For me personally, it's unbelievable." He added, "This is a remarkable and globally significant opportunity," as reported by ABC News Australia.

The week-long dissection, being led by Te Rūnanga o Ōtākou in partnership with the Department of Conservation (DOC), will help to fill in gaps about the whale's behavior, diet, and basic anatomy. Researchers studying the 5-meter long male spade-toothed whale hope to find out more about the species, providing baseline and groundbreaking information about this enigmatic whale.

Gabe Davies, the DOC Coastal Otago operations manager, said the discovery of the spade-toothed whale was "huge" from a scientific and conservation point of view, according to ABC News Australia. He stated that only six samples of the spade-toothed whale had previously been documented worldwide since the 1800s. Because so few specimens have been found and there have been no live sightings, the spade-toothed whale is classified as "data deficient" under the New Zealand Threat Classification System and by the International Union for Conservation of Nature.

The list of unknowns about Mesoplodon traversi is longer than what is known, including their habitat, reasons for never being spotted in the wild, and the appearance of their brains. Scientists don't know why spade-toothed whales have never been spotted in the wild or where in the ocean they live. All beaked whales have different stomach systems, and researchers don't know how the spade-toothed whale processes its food.

New Zealand scientists dissect world's rarest whale.The spade-toothed whale is so elusive only seven specimens have ever been documented. The dead whale washed ashore earlier this year, offering a chance to study a deep-sea mammal that has never been seen alive… pic.twitter.com/XxMuHzcFHn

— AFP News Agency (@AFP) December 2, 2024

"There may be parasites completely new to science that just live in this whale," Anton van Helden said, expressing excitement about learning how the species produces sound and what it eats, as reported by NBC News. He added, "Who knows what we'll discover?" Researchers pointed out marks from cookiecutter sharks on the beached whale, which they said were normal and not the cause of death.

The dissection is being undertaken in partnership with Māori, New Zealand's Indigenous people, who regard whales as a taonga—a precious treasure. The analysis will be respectful of local traditions, and members of the iwi (tribe) will be present throughout the dissection and will be consulted at each turn. They will share traditional knowledge and observe customs, such as saying a karakia—a prayer—over the creature before the study begins.

"According to our beliefs and traditions, this whale is a gift of Tangaroa, deity of the ocean," Tumai Cassidy from the local iwi Te Rūnanga Ōtākou said, reported The Hindu. "It's very important for us to respect that gift and to honor the whale," he added. At the end of the dissection, the iwi will keep the jawbone and teeth of the whale.

Among the scientists gathered were some who had traveled from abroad to see the whale. Joy Reidenberg, a comparative anatomist from the Icahn School of Medicine at Mount Sinai in New York, said, "What we are interested in is not only how these animals died, but how they lived," according to Phys.org. She added, "In discovering how they live, we are hoping to find discoveries that we can apply back to the human condition."

The spade-toothed whale belongs to the family of beaked whales, which are deep divers that are rarely seen at sea, presenting real challenges for researching these marine animals. "They are deep divers that are rarely seen at sea, which presents real challenges for researching these marine animals," Van Helden explained. Beaked whales are known as the ocean's deepest divers for food.

New Zealand is a whale-stranding hotspot, with more than 5,000 episodes recorded since 1840, according to the Department of Conservation, reported by The Independent. Researchers don't know how the washed-up spade-toothed whale died. The whale appeared relatively unblemished, giving no clue about its death.

The first spade-toothed whale bones were found in 1872 on New Zealand's Pitt Island. The species was first described in 1874 from just a lower jaw and two teeth collected from the Chatham Islands off the east coast of New Zealand. DNA sequencing in 2002 proved that all three specimens of Mesoplodon traversi were of the same species and distinct from other beaked whales.

Because so few specimens have been found and there have been no live sightings, the spade-toothed whale is classified as "data deficient." Scientists can now analyze a practically intact Mesoplodon traversi and hope to unveil at least some of the secrets of this elusive species. "We will be able to look at the structures used for sound production, its stomach layout, that is unique to each species of beaked whale, even down to confirming exactly how many vertebrae this species has," Van Helden explained. He said the findings might also have implications for the human threats the whales face in their environment and how such threats are managed.

This article was written in collaboration with generative AI company Alchemiq