Scientists examine transparent teeth of deep-sea dragonfish
SAN DIEGO, U.S.: Researchers have recently looked into the transparent dragonfish teeth in order to analyze their structure, composition, and mechanical properties. The study reported that the teeth of dragonfish owe their transparency to an unusually crystalline nanostructure of hydroxyapatite and collagen mixed with amorphous regions. The findings could serve as bioinspiration for developing transparent dental ceramics.
The researchers, from the University of California, San Diego (UCSD), studied the dragonfish species called Aristostomias scintillans, caught at depths of up to about 3,300 ft (1,000 m) in the Pacific Ocean off California’s coast. After analyzing the data, they reported that the dragonfish’s teeth, similarly to human teeth, are made up of enamel and dentin. However, its enamel consists of nanoscale crystals embedded in the surrounding structure, and the dentine is composed of nanoscale fibers of collagen coated with hydroxyapatite. These dental traits prevent any light existing in the near blackness from reflecting off the tooth surface and thereby enable predatory success.
“Thus, the mouth is invisible and the prey is caught more easily,” said lead researcher Dr. Marc A. Meyers, Distinguished Professor in Materials Science at UCSD. “Initially, we thought the teeth were made of another, unknown material,” Meyers continued. “However, we discovered that they are made of the same materials as our human teeth: hydroxyapatite and collagen. However, their organization is significantly different from that of other fish and mammals. This was a surprise for us: same building blocks, different scales and hierarchies. Nature is amazing in its ingeniosity.”
A small number of other fish, such as anglerfish and hatchetfish, also possess transparent teeth. “These have not been investigated yet, but I suspect they have a similar structure,” Meyers noted.
The study, titled “On the nature of the transparent teeth of the deep-sea dragonfish, Aristostomias scintillans,” was published online on June 5, 2019, in Matter, ahead of inclusion in an issue.