Plaice

Flatfish is a strange fish with two eyes on one side. It is considered that two fish should walk side by side, hence its name. It is a large class of marine fish, including fish of Silurus, Solenidae and Solenidae. Paralichthys olivaceus, PARALICHTHYS olivaceus and PARALICHTHYS olivaceus are common in the family PARALICHTHYS olivaceus. The common flounder families are "high-eyed flounder", "stone flounder", "wood leaf flounder" and "oil flounder"; "Cynoglossus" is common in the family Cynoglossus. There are 3 suborders, 9 families, about 1 18 genera and 538 species. 3 suborders, 8 families, 50 genera 134 species in China. They are all bottom-layer marine fish, and their distribution is closely related to the environment, such as ocean current, water and water temperature. For example, along the western side of the equatorial oceans, the warm current is wide and there are many kinds; There is a strong cold current along the coast of the Yellow Sea and Bohai Sea, and there are many cold and warm types. The western Pacific and the South China Sea were not strongly affected by the ice age, and there were many kinds. There are a few species in China, such as Silurus meridionalis, Cynoglossus altissima, Cynoglossus maculata and so on, which can live in fresh water areas of rivers.

Flatfish, also known as flatfish, flatfish and fish, inhabit the sandy bottom of shallow sea and prey on small fish and shrimp. They are especially suitable for benthic life on the seabed. Because their bodies are flat. Both eyes are on the upward side of the body, and the color of this side is well matched with the surrounding environment; Their downward side is white. The flounder has extremely fine scales on its body surface. The flounder has only one dorsal fin, which extends almost from the head to the caudal fin. They mainly live in temperate waters and are important economic fish in temperate waters. How did the flounder's eyes get together? It turns out that the flounder larvae just hatched from the egg membrane are completely unlike their parents and look very similar to ordinary fish. Eyes are on both sides of the head. One on each side, placed symmetrically. They live in the upper layer of water and often swim near their sleep. After about 20 days, the morphology of flounder larvae began to change. When the larvae of flounder reached 1 cm, something strange happened. The eye on the flounder side began to move. It gradually moves to the opposite side through the upper edge of the head and stops moving until it is close to the other eye. Different kinds of flounder eyes have different methods and routes to move. The skull of a flounder is made of cartilage. When the flounder's eyes start to move, the cartilage between the flounder's eyes is first absorbed by the body. In this way, there is no obstacle to the movement of eyes. The movement of flounder's eyes changes the internal structure and organs of flounder. Flounder has not adapted to floating life, so it has to lie on the bottom of the sea. Flounder is a valuable seafood. It is called PARALICHTHYS olivaceus in fishery. The body of PARALICHTHYS olivaceus is generally 25 cm to 50 cm long, and the largest PARALICHTHYS olivaceus is 70 cm. Paralichthys olivaceus will make short-distance group migration according to the change of seasons. Paralichthys olivaceus is widely distributed along the coast of China. Fishermen in the Yellow Sea and Bohai Sea use bottom trawls to catch flounder. Fresh PARALICHTHYS olivaceus can be eaten or canned. The liver of PARALICHTHYS olivaceus can also extract cod liver oil.

Ichthyologists tell us that this strange shape of flounder is not innate. The eyes of the newly hatched flounder are also born on both sides. When it grows to about 3 cm long, the eyes begin to "move". One eye moves above the head, and gradually moves to the other side with the upper edge of the head, until it approaches the other eye. The life habit of flounder is very interesting. When swimming in the water, it doesn't have its back up like other fish, but its side with eyes is up and it swims sideways. It often lies flat on the bottom of the sea, covered with a layer of sand, with only two eyes exposed to wait for prey and avoid predation. In this way, the advantage of two eyes on one side is displayed, which is of course the result of animal evolution and natural selection.

In ancient China, flounder was a strange fish symbolizing loyal love. The ancients left many beautiful sentences praising flounder, such as "The Phoenix is an amphibious fish", "Why don't you quit your job if you get a better one? You would rather be a mandarin duck than a fairy", etc. Li Yu, a famous dramatist in Qing Dynasty, once wrote a script describing the love story of a talented person and a beautiful woman, and its name was "Flounder".

In fact, the ancients had a wrong understanding of flounder. In "Er Ya Shi Di", it is said: "There is a contrast between the eyes in the East, and it is no better than it, so its name is the sole." "Wu Du Fu" also said: "Double is more than eyes, and piece is more than Wang Yu." (Note: "The flounder comes from the East China Sea. Wang Yuyu, his body is half. As the saying goes, the silver carp of the king of Yue is not exhausted, so it is half abandoned in the water as a fish, so there is no one side, so it is called Wang Yuye. " The ancients called it "flounder" because it "looks like a cow's spleen, with thin scales and purple-black. At a glance, two pieces can be combined, so it is called flounder." As I have said before, the flounder is indeed a strange fish with eyes on one side and no eyes on the other, but it is not only one eye, but two eyes are close to one side. It is a big mistake to say that it is "two pieces that fit together". How can two fish be closed together? Different kinds of flounder have different eye positions. The eyes of the flounder family are on the left, but the eyes of the sole family and the sole family are on the right.

tonguefish

Cymoglossus robustus (Cynoglossus)

[Local name] Sole fish, sole rice, tongue, ox tongue, sole fish, Longli, bald sea, fine scale, Tahitian fish, dog tongue, sole sand, ox eye, sole fish, tooth fork fish and left mouth.

[Morphological characteristics] The body is flat and tongue-shaped, with a body length of 25 ~ 40 cm and a weight of 500 ~1500g. The head is very short, the eyes are small, both eyes are on the left side of the head, the mouth is lower, the snout is bent downward and backward in an arch shape, and the left and right sides are symmetrical. The scale is large, the eye side is covered with comb, light brown, with 2 lateral lines; There is no round scale on the side of the eye, which is white and has no lateral line. The posterior nostril with eyes is located between the eyes. Dorsal fin and gluteal fin are completely connected with caudal fin; No pectoral fins; Tail fin pointed.

[Origin, season] is distributed in the western North Pacific Ocean. It can be caught in all offshore fishing grounds in China, with sea island and Shidao fishing grounds as the main producing areas. However, the fish are not dense, and many fish are caught at the same time. The fishing season is from May to July in summer and10 ~1February in autumn.

[Economic Value] Cynoglossus latifolia is one of the rare economic fish in the ocean. Each hundred grams contains protein 13.7 grams and fat 1.2 grams, and the meat is delicate and delicious, especially the fish caught in summer and flood season is the most fat, and the food is fresh and fat but not greasy. Braised tongue sole fish is one of the famous dishes. Besides fresh food, it can also be processed into salted and dried products.

I looked at the photo of Cynoglossus, and it should be it.