Arowana (dragonfish) is one of the most frightening creatures, living in the deep sea. Their shape can be said to be the idea for monsters in horror movies, with long, wide mouths filled with sharp teeth.
Although the size of the deep-sea arowanas is quite small, just under 15cm, it is enough for them to become the top food chain in the deep seabed habitat up to 1500m, similar to the shark bears, tigers, lions, … in the environment of these species. The characteristic of this species is its giant mouth with many sharp and curled teeth, allowing it to swallow its prey with half its body. The way it opened its mouth looked like a grisly smile.
This fish also has the ability to luminescence thanks to special organs along its body, which helps attract both prey and mates.
As with many other species of marine life, we know very little about arowana. One of those mysteries is, why their teeth are transparent.
Meyers, a Brazilian engineer working at the University of California, San Diego, joined his team and scientists from the Institute of Oceanography and collaborated with the German Leibniz Research Institute to work together. about arowana.
Meyers' group used a large jaw dragon to test it, with the scientific name Aristostomias scintillans, then Leibniz's researchers observed its teeth under an electron microscope.
They realized, just like human teeth, the teeth of this fish were covered with a layer of enamel, inside the dentin, but this fish evolved in a special way to make the teeth invisible.
These teeth have nanostructures, nanocrystals hydroxyapatite crystals scattered throughout these layers prevent any light from reflecting or scattering off the surface. Scattering is also the phenomenon that helps us see the sky is blue, because only the blue beam has the longest wavelength entering the atmosphere, strongly scattered by the air layer and subjected to reflection by vapor. Water and dust make the sky blue.
In the case of arowana teeth, the light beams will go straight through, making unfortunate prey to see the danger they are about to swim into.
"This is like an adaptation, part of an evolutionary competition between predators and prey.", Meyers said. “At that depth, where there is almost no light, other fish are attracted by the light of the arowana, because they think it can be food and swim closer. After that, arowanas open their mouths, and bup! So, we hypothesize that their teeth in productivity are invisible to prey. "
These creatures have a lot of mysteries, but Meyers wants to exploit the dental properties of arowanas to make glass and other transparent materials.
“In the case of these fish, there are two things that we are very interested in. One is transparency, but two, teeth can be more rigid than others, and we want to study this next. If we can develop a very hard and transparent glass or porcelain like these teeth, that could be a great thing, " Meyers said.