At the fish markets of Chile, you can buy a delicacy — live stones
The diversity of living organisms inhabiting our planet, despite the efforts of man, is still great. Some of the creatures living next to us are so unusual that it is hard to believe in their existence. For example, ascidia, which are outwardly almost impossible to distinguish from sea stones.
In the Chilean fish markets, you can see seafood, which invariably arouses the interest of all tourists. It looks like a moss-covered stone split into two halves, with tender meat inside. This marine creature is Pyura chilensis from the Ascidian class, which, despite its strange appearance, is a distant relative of vertebrates.
Instead of a spine, the "living stones" have a chord, and they feed on small living organisms that are filtered out of seawater using a special device — a siphon.
These inhabitants of the Pacific bottom have both male and female sexual organs, so there are no problems with reproduction in Pyura chilensis. The population of these creatures is growing, despite the fact that their extraction takes place on a truly industrial scale.
Ascidia of this species are born quite unlike adults. Pyura chilensis babies have a tail, a brain, and even eyes. But all these organs are used only to find a suitable underwater rock on which you can spend the rest of your life.
Anchored to the stone, the young ascidia loses the organs of vision, tail and, finally, the brain, which turns into a nerve node that controls reflexes. At this point, the transformation of a young chordate organism into an adult dull stone is completed and Pyura chilensis can only be covered with a layer of marine vegetation in order to reliably disguise itself.
Some parts of the coast of Chile and Peru are covered with a solid layer of "living stones" and you can collect them as much as you want. Despite this, the meat of this type of ascidia is sold in markets and shops as a delicacy and is not cheap at all. A dish from Pyura chilensis needs to be able to cook, so it's better not to take it without culinary experience. But even cooked taking into account all the important nuances, ascidia is not too tasty and, according to some, resembles soap.
In addition, in Japan, ascidium is used in... metallurgy. The fact is that the blood of these creatures is very rich in vanadium and this rare metal on our planet is easier to extract from marine life than from ore. To obtain precious raw materials for metal smelting, the Japanese burn Pyura chilensis, and their ashes are sent for processing.