Pearl Gentian Grouper , also known as Dragon Tiger Grouper or Pearl Spot, is a new hybrid species Grouper bred from Gentian Grouper (♂) and Tiger Spot (♀). Its meat is tender and It grows quickly and has strong disease resistance. It has the appearance of tabby, heads, and gentian tail, showing hybrid advantages. The market price of commercial fish is good, and it can also be used as an ornamental fish. It has a broad market prospect. At present, Pearl Spot accounts for 70% of the grouper cultured in Hainan, becoming the number one brand of grouper cultured.
However, in recent years, the incidence and mortality of pearl gentian grouper have been increasing year by year. In addition to the common diseases that have been systematically studied, such as black body, rotten body, white stool, etc., there is also a kind of big spot that is spread among the people. The losses and impact on farmers are also expanding. In some places, it has even reached the point of "talking about it big". color change" point. Last year, Dongao had a customer who raised more than 10,000 kilograms of fish. The market price at that time was 34 yuan/jin. After seeing the fish, he said it was a large spotted fish, and finally sold it for 24 yuan/jin. It is such a pity to lose hundreds of thousands in an instant. So, what are large spots, how to distinguish large spots and what are the dangers of large spots? This article will give you a brief introduction. I hope you will have more knowledge and understanding of Big Spots, which will be helpful to your future breeding.
Large spots (spots), as the name suggests, are irregular dot-like patterns appearing on the body of pearly spots. Normal pearl spots have vertical stripes, with a total of 5 stripes from beginning to end. The first and second stripes are connected by a horizontal stripe, forming an "H" shape; the last three stripes are all vertical. (Figure II). The pattern of large spots is very scattered and fragmented. Unlike normal pearls, which have five vertical lines, they are shaped like large spots, so they are called "big spots" (Figure 3).
So, how do big spots form? Let me share with you a true story. Wanning There was a father and son raising pearl pods. They brought a batch of seedlings back and put them in a pond. After they were grown, they divided them into two ponds, and one person was responsible for one pond. . When they were finally raised, the fish in one pond were normal, while the fish in the other pond were all large spots.
Back to the original question, how do large spots form? In response to this issue, the author has reviewed relevant information, but there is no literature or information with reference opinions. But one of the mainstream theories now is the theory of genetic factors + environmental disease. Pearl spot is a hybrid species, and its hybrid advantages are also used. However, the current seedling breeding is still in an extensive stage. It is not systematic, not large-scale, and each has its own faction. "A hundred schools of thought are competing but nothing is happening." We cannot yet interfere with its gene expression, so during breeding, the dominant traits will be clearly displayed, but the variation, inheritance, and expression of some other recessive traits cannot be avoided. As the current large-scale breeding environment continues to deteriorate, germplasm resources continue to degrade, and medications are also high-cost and low-level, resulting in many common diseases becoming more and more difficult to treat, and uncommon diseases have no cure. What are the dangers of
large spots? Why is everyone so against Big Spot? The first is the example mentioned in the article. Large spots are difficult to sell and have low economic value. In addition, ponds with large spots often experience wear and tear, especially when environmental factors and management problems arise. For example, sudden changes in weather, excessive feeding, drug abuse, etc. As for the death of large spots, there is no drug that can control it so far. In October last year, an owner of Yinghao Peninsula in Wanning had a large pond with large spots, which caused a lot of losses. The loss was 200 pounds per day, which lasted for more than a month. All kinds of medicines have been used, but to no avail. About 6,000 pieces were lost before and after, causing a lot of losses.
When large spots appear, it is rare for all fish in a pond to have large spots. In addition, if large spots appear in one pond, they will not be found in the next pond. It can be concluded that large spots will not be horizontally transmitted, that is, they are not contagious. Under normal circumstances, the feeding and activities of large spots are no different from other normal pearls, but their ability to resist stress is very poor. Once environmental factors change, large spots are the first to die. Deaths with unknown symptoms and unexplained causes often occur.
So how to avoid growing big spots? First of all, when getting seedlings, it is best to go to a place with good reputation and good quality. Secondly, it is difficult to distinguish the seedling stage. You can find someone who can see the seedlings to get the seedlings with you. Finally, it is recommended that everyone try to get large-sized seedlings if possible. In addition to the seeding process, daily pond management cannot be ignored. Many disease causes are opportunistic pathogens, which will induce diseases only when certain conditions are met. Regularly improve the bottom of the pond, detoxify, and transfer water to provide the fish with a comfortable living environment and reduce stress factors in the breeding pond. This can not only greatly reduce the probability of fish disease, but also increase production and economic benefits. Why not do it? Woolen cloth!
Author: Yumeikang Group Chen Chaoshan
