The mature Arapaima is one of the largest freshwater fish in the world, reaching a maximum length of 4.5 meters and weighing 200 kg.
But do you think arapaima will be a dish on your table? If you don't look good at my copvin, one bite down may jump your teeth.
Giant arapaima, although their scales are very thick, but still on the human table. Arapaima macrophylla has enormous economic value. A giant arapaima has an average of 70 kg of fish meat. In Brazil, indigenous peoples can hunt a certain number of arapaima for food with the permission of the local government, but there are strict limits on the number and size of the fish.
The scales of the arapaima have a soft and tough inner layer, which is combined by collagen and its outer layer of mineralization. Other fish, like the Arapaima macrobrachium, are also rich in collagen in their scales, but the collagen layer in the scales of Arapaima is thicker than any other fish.
The tissue structure of the fish scales of Arapaima macrophylla. This structure provides them with a survival environment in which piranhas are found.
How awesome is this collagen layer? Check out the next experiment!
After fixation and staining, the samples were dehydrated by ethanol, a mixture of ethanol and water, and acetone, and finally embedded in a low-viscosity resin and pressed, and reacted at 60 °C for 48 hours.
however! Even after such torture, when the experimental team put pressure on them, they could only let the outer part peel off, and then the pressure would be blocked by collagen.
After reading this, you may not know how awesome it is, but I interjected: "As we all know, what is the 'specialty' of the Amazon River?" ”
Piranhas!
This giant arapaima live with piranhas, and piranhas can bite through even body armor, so you can imagine how high-quality this structure is.
The bite force of the piranha's upper and lower palates is amazing, it can bite through cowhide or even hard wooden planks, and it can bite off the steel fishing hook, and other fish are certainly not its opponents.
With this resilient hierarchy of fish scales, we can make more comfortable and sturdy artificial armor. However, this biomaterial may take many years to make.