Science Reporting

Strange fish from the depths with transparent teeth studied by scientists

A group of researchers from the University of California in San Diego analyzed the teeth of sea dragons (Aristostomias scintillans) characterized by a remarkable degree of transparency. This unique adaptation allows these fish to prey more successfully. Scientists have discovered an unusual crystalline nanostructure at the base of their teeth, a discovery that could be of inspiration for the construction of transparent or semi-transparent materials with a similar structure.

The research, published in Matter, describes the transparent teeth of sea dragons (dragonfish), an adaptation that, unlike others related to marine animals, such as bioluminescence, has never been properly analyzed on a scientific level, as pointed out by Audrey Velasco-Hogan, the first author of the study that adds: “By studying why these teeth are transparent, we can better understand deep-water organisms such as dragonfish and the adaptations that have evolved to live in their environments.”

Thanks to their transparent teeth, combined with the fact that their bodies are almost completely dark, these fish are essentially invisible to their prey. This makes them excellent predators despite the habitat in which they live, the depths of the sea, is not very generous in terms of the presence of light and despite the fact that they are fish considered as slow. Basically, these fishes spend most of their time waiting for the prey that approach. The same prey cannot notice the protruding teeth that do not reflect light being transparent and therefore meet their destiny.

The teeth of these fish have unique characteristics with regard to both the outer enamel and the inner layer of dentin. The outer layer is made of hydroxyapatite nanocrystals, a structure that prevents light reflection. But also the inner layer is quite particular: there are no classic microscopic channels, called dentine tubules, which are the basis of the teeth of many animals. The absence of these tubules means that the teeth are transparent.

These discoveries could be useful for creating a transparent material in the laboratory.