The creature in the world that looks most like a dragon is actually a "nerd"!

15 million years ago, there lived a group of slender, black-bodied amphibians that knew cool drizzles and had basked in the sun.

However, millions of years later, due to environmental changes, they had to move to underwater caves under the Alps in southeastern Europe, and gradually evolved into a snow-white, eyeless creature. They are the cave salamanders (Proteus anguinus) .

Since the 17th century, biologists have begun to pay attention to a special ecosystem - underground aquatic cave systems .

The biggest difference between this system and other habitats is that food is scarce in the cave, light is scarce , and seasonal and annual environmental changes in the outside world have little impact on the cave . In this way, those who can live here are not "ordinary people".

However, with the in-depth study of underground caves over the past few centuries, people have found that although there are many "residents" in the caves, most of them are just ordinary "hole diggers" and are not special. It was not until the discovery of the cave olm that people saw what the real "king of the cave" is.

The olm is the only cave-dwelling chordate amphibian since the Paleogene, and is also a European iconic species. It is the only species in the genus Olm in the family Olmida. In 1768, Austrian natural scientist Laurent discovered the olm and named it "Proteus". This name comes from the name of an old and stubborn sea god in Greek mythology. Perhaps it was the strange appearance of the olm that gave Laurent a wonderful association.

Having lived in dark underground caves for a long time, the olm thought: What’s the use of having eyes in this damn place? I can’t see anything anyway, so I might as well retreat.

As a result, the eyes of the cave salamanders gradually degenerated and sank into the skin . However, every loss has a gain. Without vision, they evolved their hearing and sense of smell to the extreme.

In 2010, zoologist Jay of the University of Budapest and his colleagues discovered the olm in a limestone cave in eastern Bosnia and Herzegovina.

After diving into the cave several times, they discovered a strange phenomenon: each time they went down, the scene was basically the same as the last time . For example, they could always see a cave salamander in the same location, and it looked like the same one every time. The researchers once wondered if they had been hit by "Izanami" (a pupil technique in the anime Naruto that can cause people to fall into an infinite cycle of reincarnation).

To solve the "illusion", the researchers used the classic mark-recapture method , followed by injection of a marker-tagged fluid, to record 26 olms found in the cave. Each olm used a different marking pattern, allowing the researchers to identify them visually.

After an eight-year tracking study, researchers found that these creatures only deviated from their original position by about 10 meters in a few years, which means that in eight years, these olms had almost no movement . One of them even remained motionless for 2,569 days, which is almost seven years!

This result was a bit unexpected for everyone. One of the team even thought that the olm might have been wandering in the cave, and then returned to the same place in time when they came back.

You think the olms are on the first level, but they might actually be on the fifth level.

However, the real reason for their inactivity is environmental pressure . As mentioned earlier, due to the scarcity of food in aquatic cave systems, olms rarely eat meat a few times a year. In many cases, they have a full meal and then go hungry for a few years.

Therefore, in order to maintain various life activities of the body, the olm will actively slow down its metabolism and reduce all energy consumption. For example, the olm is too lazy to do the important things like "sexual intercourse" to "continue the family line". Studies have shown that the frequency of olm mating is once every 12 years, and females only lay eggs once every 7 years. The reproduction rate is lower than that of its close relative, the salamander.

Olma eggs

In addition, the distribution of food in the cave is actually quite uniform, and the probability of catching prey in each location is about the same. In this case, there is no need for the olm to expend too much energy looking for food. Waiting for prey to come to them is their best hunting technique (the ancients were not deceiving me).

Not wanting to move, not wanting to reproduce, not wanting to hunt...if it were any other species, they would have basically become extinct long ago, but the cave olm has relied on this "homebodies" spirit to live alone and quietly in its "paradise" of underground caves for century after century.

This seems to be the kind of life that most modern people pursue, comfortable and free.