"Smart and intelligent" marine resident animals, they live in a variety of ways!

Making a living in dangerous seas is not easy. With the exception of a few top members of the food chain, such as sharks and killer whales, the harsh reality of hunting and being hunted at the same time keeps most creatures living in terror. Conversely, some "hermits" are frail and forgettable, yet at ease, their lifestyles and skills will amaze even the most imaginative scientists.

Sojourn means being "ruined" by rhododendrons on land. The fact that an ungrateful creature like the cuckoo is rare in nature, especially the phenomenon of sojourning in the ocean, gives sojourn a positive meaning as it creates harmony and mutual prosperity. Unlike land animals, for marine life, shelter is more important than food. As the saying goes: the people take food as the sky, and the fish take the dwelling as the foundation. the reason is simple. Fish can go without food for a month or two, but if you don't pay attention to concealment, they may be eaten by big fish.

The smartest resident animal is the two-banded double sawfish. Because of its bright color, it is also called "beautiful fish". Its host is the sea anemone. Sea anemones are coelenterates that specialize in preying on small fish such as belle fish. It has no skeleton and has a cylindrical body. It attaches suction cups to reefs or stationary objects during the workday. At the other end, it has a slit-like throat surrounded by flexible and powerful tentacles. When swimming, the slender tentacles drift with the current, like blooming chrysanthemums. Upon encountering a small fish, the highly toxic cells on the tentacles immediately release a toxic anaesthetic, subduing the prey, which is then sent into its own mouth for slow digestion. Marine biologists dive into the bottom of the sea to observe, as long as they touch the venom of its tentacles, they will be eaten or suffocated to death.

At the end of the 19th century, on the islands between New Guinea and Australia, scientists were surprised to find that sea anemones, which were originally natural enemies, had a natural and intimate parasitic relationship with belle fish. Among the sea anemones, the belle fish can come and go freely. Every night or when danger comes, the anemone's body cavity becomes a hiding place for the belle fish. In order to express their gratitude, when the risk factor is small, the belle fish will lure the rash suitor to the tentacles of the anemone, and make it a snack for the anemone, saving the anemone the pain of running around. In addition, the beautiful fish will donate their prey to the sea anemone in their spare time to express their gratitude. At first, no one believed it to be true.

It wasn't until 30 years ago that scientists uncovered the secret that this beautiful fish is not afraid of sea anemone venom. It turned out that in order to prevent the venom from harming itself, the sea anemone will release the venom and secrete a kind of mucus that evenly covers the body to form a protective film. In this way, they will not be corroded by their own venom, but also resistant to accidental damage of the same kind.

This careful and smart beauty fish has discovered the secret of the anemone, so when the fish decide to establish a sojourn relationship with the anemone, they will go to the anemone in the sea to get close to the anemone. In the beginning, had to endure the pain of numbness. After getting the protective film, the pain is relieved naturally. After a few times, with a protective film like the body of an anemone, not only is there no pain, but lifelong immunity. This is the secret why belle fish can form a sojourn relationship with sea anemones.

In addition to careful observation and experience, the success of the beautiful fish lies in its gratitude and the establishment of a long-term mutually beneficial relationship with its owner. People have reason to believe that if the belle fish blindly threatens to see through the secrets of the sea anemone, instead of making a living for the sea anemone with snacks, the sea anemone will never let the delicious belle fish dangle in front of her eyes. as your own home. In some cases, wisdom means giving.

Small diving fish in sea cucumber

In contrast, the small diving fish that live in sea cucumbers are not so kind. This transparent and thin fish ignores the tolerance and kindness of sea cucumbers at all. They enter the anus of the sea cucumber at will, use the mouth as an outlet, and go in and out at will, and they turn a blind eye to the stomach pain caused by the sea cucumber. What's more, six or seven small diving fish made the sea cucumber's stomach bloated, causing irreversible damage to the sea cucumber's organs, and even death. There is a difference between good and evil, not to mention fish.

Male and female light stick fish

A fish that lives in the deep sea is of great interest to marine biologists because only the females are raised, while the males are never seen, and not even 60-year-old fishermen have ever seen them. This is a light stick fish that lives in warm water currents.

The researchers speculate that the males must be too small to find. Gender differences in the sea world are sometimes staggering. For example, the female conji eel weighs 45kg, while the male is only 1.5kg. On February 12, 2015, Seattle Aquarium biologist Roland Anderson discovered the first living male octopus on Australia's Great Barrier Reef. Scientists measured the octopus to be only 2.4 centimeters long and weigh 0.25 grams, while female octopuses are usually 80 centimeters long and weigh 3 kilograms. The largest female octopus found so far is nearly 2 meters long and weighs 10 kilograms, nearly 40,000 times heavier than the average male octopus.

The difference between males and females in light stick fish is not as great as that in octopus. The reason they are so hard to find is that males live off females. In the process of dissecting the female light stick fish, people were surprised to find that there are tiny protrusions under the skin of the female light stick fish. Although they vary in location and size, they are present in almost every female ray stick. It turns out that they are male fish attached to the female fish.

This is a helpless and appropriate choice, not only for survival, but also for reproduction. It is more convenient and effective to have no such male possession of the female body. In the depths of the pitch-black waters, visibility is extremely low, and the male light stick fish has degraded vision, slow movements, and is struggling all day long on the verge of death. The greatest luck in their life is to meet a female of the same kind, and then they will try to get close to each other and "meet each other".

The reward of perseverance makes the male light stick fish excited, and once it is successfully attached, it can not only calm the sexual impulse, but also obtain nutrition. It combines its own blood vessels, and even its body, with the female, allowing its mate to provide for itself. So they form another hermaphrodite in the biological world.

There is no free lunch in the sea. The evolution from sojourner to parasite comes at a price. Males are the best proof. Because there is no need to rush for food, its eyes, mouth, fins, gills and other organs have degenerated, leaving only some traces. The only thing that is strong is its sex organs. Without this capital, it loses the capital to stay. According to evolutionary theory, its sexual organs should not degenerate.

If it's wise for males to choose to stay with females all their lives, then prawns and sponges seem helpless.

Sponges appeared in the Paleozoic Cambrian ocean. They still live on the ocean floor hundreds of millions of years ago. They have no mouth, stomach or digestive cavity. They rely on inlet pores on the surface of their body walls to filter nutrients from seawater. The lily shrimp is a soft and transparent sojourn shrimp. It swims into the sponge along the water inlet hole of the sponge. Coincidentally, there are also prawn prey running on sponges in the sea. Therefore, there are good reasons for the prawns to settle in the water inlet holes of the sponges. Not only does it prey, it also prevents it. Li Shrimp immediately fell in love with this cozy nest.

What Li Shrimp didn't expect was that he would grow up over time. He came in easily as a kid, but couldn't get out as he got older. What can he do? Li prawn's stay is indeed an option. From the day it entered the sponge, its fate was decided. As the saying goes: do not seek to be born in the same year, month and same day, but seek to die in the same year, same month and same day.

The good news is that the shrimp and sponge live in harmony and understand each other. Sponge doesn't resent Li Shrimp for fighting for his food; Li Shrimp doesn't get angry at losing his freedom, like a pair of old people who got together and went to the end of their lives alone.

People always give good explanations for things they don't know well, and the story of Li Shrimp and Sponge is no exception. So they were given the classic of loyalty and righteousness, and the Japanese invented a nice word for this, called "keep together with old people". They also stuffed sponges and shrimps together and gave them to relatives and friends for senior weddings.

If the souls of these two creatures were aware, they would not know how they felt. Sponge may have nothing to say. Li Shrimp has to argue. The reason is simple - freedom is precious to all life, and can even be exchanged for life.