For the first time, scientists have confirmed the existence of ginkgo-toothed beaked whales (Mesoplodon ginkgodens ) in their natural habitat after decades of relying solely on stranded carcasses. This elusive species, known for its unique tusk-like teeth in males, was tracked down through persistent underwater acoustic monitoring off the coast of Mexico. The breakthrough highlights how little remains known about deep-sea cetaceans, and the extreme measures researchers take to study them.
The Hunt for an Underwater Ghost
Beaked whales are among the least understood marine mammals, spending most of their lives in deep, remote waters. This makes direct observation exceptionally difficult. Researchers began searching for the ginkgo-toothed whale in 2020 after detecting a distinct echolocation signal. In June 2024, their efforts paid off, leading them to a small group including an adult male with visible battle scars, an adult female, and a calf.
Identifying the Species: A Painless Biopsy?
Distinguishing between beaked whale species visually is challenging. To confirm their discovery, the team opted for a controversial method: collecting a DNA sample by shooting one of the whales with a modified crossbow. The researchers insist the procedure is minimally invasive, extracting only a tiny plug of tissue. They compare the impact to an ear-piercing gun, noting that cookiecutter shark bites likely inflict far more damage.
Why a Crossbow?
The team has used this method for decades, collecting thousands of samples from various whale and dolphin species. They argue it’s the most efficient way to obtain genetic material from elusive deep-sea creatures without causing serious harm. The tissue sample confirmed that the whales were indeed M. ginkgodens, though their presence in this part of the Pacific was unexpected.
The Purpose of the Tusks
Male ginkgo-toothed beaked whales develop a pair of enlarged teeth that protrude as small tusks. These aren’t used for feeding – the whales suction-feed on squids and fish – but for aggressive displays. The tusks serve as weapons in battles over mating opportunities, with the scars on the observed male suggesting frequent conflict.
The Bigger Picture
This discovery underscores the vast gaps in our knowledge of marine life. Acoustic monitoring is becoming increasingly vital for tracking these hidden species. By linking underwater calls to specific whales, researchers hope to map their distribution, estimate population sizes, and assess their vulnerability to human threats such as fisheries.
“This is important because once we match up the calls to all the individual species, then we can use passive acoustic monitoring… and finally learn where these whales live, how many there are, and how vulnerable they are.” – Robert Pitman, Marine Mammal Institute
The successful identification of the ginkgo-toothed whale serves as a testament to dedicated research, even if it requires unconventional methods. It also highlights the urgency of continued exploration, as many other deep-sea species remain unidentified, leaving their fate uncertain.
