A strange metal lurking in a mollusk at the bottom of the ocean

Mollusks are one of Earth’s most varied phyla, comprising nearly 100 thousand species. Many of these species have only barely been studied, and much about them remains unknown. Take Aegires albus, for instance: This species of sea slug lives in the remote Antarctic Ocean and feeds on sea sponges, but little else is known about it.

Some answers could be found in studying its teeth. Like some other predatory mollusks, A. albus possesses a radula, a specialized tooth designed to pierce and rip out parts of its prey. Understanding the structural composition of the radula can help researchers learn more about its preferred prey, typical habitats, and behavior.

Using scanning electron microscopy, confocal laser scanning microscopy, energy-dispersive X-ray spectroscopy, and nanoindentation, Krings et al. analyzed the radula of A. albus, revealing its structural gradients and the unusual presence of vanadium.

“Whenever I’ve looked at different radular teeth, I’ve never found vanadium,” said author Wencke Krings. “What we know is that we find it in the radular teeth, and we only find it in the radula. But we are not exactly sure what vanadium is doing there.”

The researchers did observe a gradient of vanadium on the outside of the tooth, ranging from low vanadium concentration at the base to a high concentration at the tip. This has led the team to speculate that vanadium contributes to the durability of the tooth, and they plan to use Raman spectroscopy in subsequent experiments to confirm their hypothesis.

“I think what would also be important would be to have an idea of where they get it from,” said Krings. “And why are they capable of incorporating it and other species are not?”

Source: “Vanadium in the radular teeth of the Antarctic Aegires albus (Nudibranchia),” by Wencke Krings, Levin Uhlmann, Heike Wägele, and Stanislav N. Gorb, Biointerphases (2026). The article can be accessed at https://doi.org/10.1116/6.0005547 .

This paper is part of the Biomimetics of Biointerfaces Collection, learn more here .