Shulou(Shulou.com)11/24 Report--

Fish dishes often appear on the table of New year's Eve dinner, and one of the common fish dishes is Pomfret.

Of all Pomfret species, Silver Pomfret (also known as White Pomfret, Pampus argenteus) is the most delicious. There is a saying, "there are partridges in the mountains and mackerel Pomfrets in the sea."

Silver Pomfret (Pampus argenteus) (photo source: wikimedia) but even if you are a seafood glutton, you may not have seen the real silver Pomfret. In fact, even many fishermen do not know that the live silver Pomfret looks like this: the live silver Pomfret has a black belt.

Why have most people never seen the real body of Silver Pomfret? It starts with the fact that silver Pomfret is becoming more and more expensive.

Silver Pomfret was originally widely distributed along the southeast coast of China and near the Indian Ocean. They are not only seafood loved by the Chinese people, but also eaten by Koreans, Japanese, Indians and Kuwaitis.

Fried Silver Pomfret (Photo: wikimedia) but have you noticed that Silver Pomfret is getting more expensive and smaller? This is mainly because the number of silver Pomfret in the sea area near China has decreased year by year since the 1990s.

Not only our country, but also other countries that like to eat silver Pomfret can't get much silver Pomfret.

For example, the number of silver Pomfrets in the Indian Ocean is also declining. According to statistics from India's Central Marine Fisheries Research Institute (Central Marine Fisheries Research Institute), along the Indian Ocean, the number of silver Pomfrets fell from 34072 tons to 27515 tons in 2011-12 alone, a decline of as much as 20 per cent.

(photo source: wikimedia) and because the price is higher than that of other Pomfret, some vendors will mix it with Chinese Pomfret (also known as Dou Pomfret, Chinese Pomfret, Pampus chinensis), which is not so delicious but very cheap. You may have eaten fake silver Pomfret for years and don't know yet.

Chinese Pomfret (Pampus chinensis) is very similar to Silver Pomfret (Photo: FishBase.se). Will the braised Silver Pomfret become extinct in the future? Why not raise silver Pomfret in hand?

Foodies who do not want to create a generation gap in food have already taken action, but countries have not been successful in half a century.

People began to try to breed silver Pomfret artificially as early as the 1960s, but the fry of silver Pomfret at that time often died a few days after hatching. Shi Zhaohong, a researcher at the East China Sea Fisheries Research Institute of the Chinese Academy of Fisheries Sciences, said that this is why silver Pomfret culture has always been a "world-class" problem, so it is called "the most difficult fish in the world."

(photo source: wikimedia) this also explains why in 2000, the Kuwait Institute of Science (the Mariculture and Fisheries Department of Kuwait Institute for Scientific Research), which received a 4 per cent survival rate of fry, called its results a "breakthrough".

So, why is it difficult to raise silver Pomfret?

The first reason why silver Pomfrets are difficult to raise is that their scales are really too brittle. Their fish scales are so small and so few that they will fall off if you touch them a little. As soon as they fall off the scales, they are easy to die from infection.

Secondly, the silver Pomfret is still a "glass heart". They are very timid, the waves are big, the water is salty, the water is dilute, and they will jump to death, resulting in scale loss.

Silver Pomfret will also take away a mysterious organization on his body when he dies, that is, the black belt.

The lower caudal fin of the living immature silver Pomfret has a black belt (photo source: see watermark). The lower caudal fin of the immature silver Pomfret is actually very long and black, sometimes up to twice the length of the upper caudal fin. Shi Zhaohong said that about half of the silver Pomfret's tail fins will lengthen into a black belt, which will fall off after the silver Pomfret's death, but researchers do not know the role of this black belt.

That's why even fishermen don't know what a live silver Pomfret looks like.

The third difficulty in artificial breeding of Pomfret is egg collection.

If you want to raise silver Pomfret in captivity, you must first get fish eggs, right? But the wild silver Pomfret will die to show you as soon as it comes out of the water, and it won't give you a chance to leave a seed at all.

So, how about taking "essence" from dead fish?

Shi Zhaohong says it's not that they haven't tried. However, as soon as the wild female Pomfret struggles out of the water, the eggs are "pulled" into the sea.

Later, researchers in our country and Kuwait finally came up with an idea.

At that time, in order to get the sperm and eggs of Silver Pomfret, Chinese researchers caught fish directly in the sea water and then inseminated them on the spot when they were frightened out of the water. Researchers in Kuwait also got fish eggs from the wild around 2000.

Getting fish eggs is only a small achievement, because silver Pomfret's small fish larvae are difficult to raise.

Silver Pomfret likes to eat live jellyfish and all kinds of gel-like plankton, not pellet feed. But feeding jellyfish to them can be troublesome and costly.

In 1998, researchers at the Kuwait Institute of Science came up with the idea of bumper shrimp (Artemia nauplii). After feeding the shrimps for a period of time, the small silver Pomfret can adapt to the fish feed, and then they switch to the fish feed.

Harvest Shrimp (Artemia nauplii) (Photo: Matthias Wiesensee) at first, Shi Zhaohong and his colleagues used a similar method. They raised a batch of harvest shrimp and rotifers (Brachionus plicatilis), used them to feed small fish, and then converted them into feed.

Despite the reversal from "cannot" to "can", the commercial value of artificial silver Pomfret 20 years ago is not clear. In 1998, the survival rate of fish fry in Kuwait was only about 4%. In 2009, the survival rate of silver Pomfret fry by Shi Zhaohong's team was 14%. Compared with other commercial fish species, this survival rate is really not very good.

(photo Source: wikimedia) but later, Chinese researchers improved the seedling raising technique.

When promoting silver Pomfret fry in 2019, Wang Yajun, an associate professor at the School of Oceanography of Ningbo University, said that the survival rate of silver Pomfret fry in China has reached more than 75%, the number of seedlings has reached more than 200,000, and the level of breeding technology is the highest in the world. "

What method did they use?

It turned out that they used raw seafood to "eat" silver Pomfret fry. They let the jellyfish eat the feed and turn it into a "Trojan horse", and then feed the jellyfish wrapped in the feed to the silver Pomfret. After eating jellyfish stuffed with feed from an early age, silver Pomfret can gradually adapt to the feed.

(photo source: Internet) however, even if silver Pomfret learns to eat feed, the problem is only half solved, because the eating appearance of adult silver Pomfret is really too bad.

Other commercial fish species are free to eat feed that floats on the surface or sinks at the bottom. For example, cheap golden Pomfret (Trachinotus blochii) can eat floating feed freely, so they are easy to raise and cheap.

Golden Pomfret (Trachinotus blochii) (Photo: wikimedia) but not Silver Pomfret, their mouths are not "normal": their upper jaws can't be moved by skin, and their mouths can only be closed by the lower jaw.

But their jaws are also indescribable, in short, an all-embracing form. In technical terms, the mouth of Silver Pomfret is "inferior" and there is no way to eat water feed.

Silver Pomfret can't move its upper lip (photo source: FishBase.se) well, you can always eat underwater feed, right?

Silver Pomfret doesn't eat either.

Of course, this can not be blamed for silver Pomfret, because their bodies are flat and flat, and they have to swim all the time so as not to roll over. If you are full in one breath, you may lie flat and scratch the scales on the bottom of the sea and die. That's why they don't touch underwater feed.

Because of its wide mouth and flat figure, Silver Pomfret can only eat food in the water, and it has to take two bites and run for a while and then come back to eat, much like you who were chased and fed when you were a child.

But even in the face of such a difficult silver Pomfret, researchers have recently found a way to raise them on a large scale.

The above-mentioned Shi Zhaohong team spent 20 years designing a special dining table and accommodation for Silver Pomfret.

The feed net specially used to feed the adult silver Pomfret (photo source: see watermark) the silver Pomfret table they designed is "hanging" type, is very friendly to the strange silver Pomfret mouth, and the feed will not fall to the bottom of the water to pollute the water; the farm is a medium-sized artificial seawater pond.

Seeing that the silver Pomfret was finally fed by human beings, everyone must have drooled with relief. I hope that the breeding method in our country can be popularized as soon as possible, so that this delicacy will not be lost.

When he was alive, he was in the underworld, and he was innocent after death.

Reference:

Https://docs.qq.com/doc/DVE9jVUFPZWN6ZXhK

This article is from the official Wechat account: bring Science Home (ID:steamforkids), author: everything.

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