Freshwater grouper aquaculture prospects
In 1996, Guangdong and Jiangxi breeding units were introduced from Taiwan. in 1999, it was introduced to Jinan Freshwater Aquaculture Scientific Research Institute. Freshwater grouper with its fast growth rate, low oxygen resistance, strong disease resistance, and beautiful appearance, delicious meat, rich in nutrients, can be used as both commercial fish, but also as ornamental fish species, is a very worthwhile species to promote. Since then, the research on the culture technology of freshwater grouper has attracted the attention of the domestic aquatic workers, and the scale of freshwater grouper culture is also getting bigger and bigger, which has become a new species of freshwater culture.
There is also a kind of native grouper in the Minjiang River system in the west of China, the tributaries of the Yangtze River and other rivers, which is relatively small in size, with an adult body length of about 18~~25CM and a body weight of 100~~250g, and it is named because it lives in the freshwater all the year round to nibble on the plankton and insect aquatic larvae attached to the stone wall. Its growth rate is slow, but it is resistant to low oxygen, strong disease resistance, and beautiful appearance, delicious meat, nutritious, can be used as a commercial fish, but also as an ornamental fish species.
The average meat content of freshwater grouper is 78.8%, the moisture content in muscle is 76.00%, crude protein is 18.90%, crude fat is 3.00%, and crude ash is 1.73%. The muscle contained 18 kinds of amino acids, the total amount of amino acids was 15.74% of the fresh samples, among which the content of 8 kinds of essential amino acids was 6.88% of the total amount of amino acids, accounting for 40.60% of the total amount of amino acids, and the content of 4 kinds of fresh amino acids was 7.08% of the total amount of amino acids, accounting for 44.98% of the total amount of amino acids. The essential amino acid index (EAAI) is 74.84; the branch/aromatic value of amino acids (BCAA/AAA) is 2.22. The saturated fatty acid accounts for 34.09% of the total fatty acid content, and the unsaturated fatty acid accounts for 65.91% of the total fatty acid content, among which the content of DHA is rich, accounting for 6.95% of the total fatty acid content. Mineral content is rich. The results of the comprehensive analysis showed that the freshwater grouper is a kind of high quality freshwater fish with high nutritional value.
In summary, the prospect of freshwater grouper farming is great.
Freshwater Grouper Fry Culture
Freshwater grouper fry cultivation pool is good for soil pool, also can use outdoor cement pools, general area of a single pool is 50-100m3, water depth l-1.5 meters. Before stocking, drain the pool, disinfect the pond thoroughly with quicklime, and fertilize the water with enough base fertilizer, so that the fish fry can eat natural bait in the pool.
Before stocking the fry, the water should be tested. The same pool stocking specifications require neat, consistent size. The stocking density depends on the bait, the level of breeding technology and the cultivation specifications, and the general stocking density is about 100 tails/m3. Fry should be soaked in sop salt water for 15-20 minutes before entering the pool.
In the process of fry cultivation, due to fertilization and baiting, the leftover fecal residue bait is most likely to spoil the water quality, for this reason, the water should be changed every 3-5 days, each time the amount of water changed for the pool of water 1/4. You can also transplant some duckweed or water hyacinth and other aquatic plants to purify the water quality and to facilitate the fry to hide, eat.
When there is a big difference in the specification of the growth of the fry, because of its habit of eating small, therefore, it is necessary to sieve and raise in a timely manner. The same pool of fish fry, and strive for the same specifications, so as not to affect the survival rate of fish fry.
Freshwater grouper for the bottom fish, low oxygen tolerance, strong disease resistance, in the breeding process rarely occurs fish disease, can be mixed with tilapia, crucian carp, in order to remove tilapia, crucian carp ponds in small fry, to achieve high-quality and efficient results.
Daily feeding of freshwater grouper
The main thing is to patrol the ponds and observe the situation of fry feeding, activities, water color changes, etc., so as to adjust the feeding amount and do a good job of preventing fish diseases.
Freshwater grouper can be raised in mixed culture, two methods can be used in mixed culture: one is to mix a small amount of freshwater grouper in the pond, mixing freshwater grouper 22-50 tails per acre of water surface, after half a year of breeding, the weight of an average of up to 300 grams or more, and after a year of breeding weight of up to 500 grams or so.
The second is the main fish for freshwater grouper, mixed species of tilapia, grass carp, crucian carp, etc., per mu of water surface stocking of freshwater grouper 150-200, mixed fish 300, feeding artificial feed, but also can be fed with fresh pasture, when there is a shortage of zooplankton in the pool, need to be appropriate amount of fertilizer, in order to cultivate zooplankton. After half a year of breeding, the average weight of freshwater grouper can reach about 200 grams, and after a year of breeding, the weight can reach more than 250 grams.
When the freshwater grouper fry come down to the pond, they feed on zooplankton. With the growth of the fry, the amount of feeding increases, and the zooplankton in the pond gradually decreases. At this time, the zooplankton can be cultivated through fertilizer, can feed more soybean milk. After 15-20 days of cultivation, when the fish fry reached more than 3 cm, its food began to transform, then you can feed minced fish on the food table to tame the food, 2-3 days after adding a small amount of artificial feed mixed with minced fish feeding, and then gradually increase the proportion of artificial feed, reduce the amount of minced fish, until all the use of artificial feed.
Artificial feed protein content in 35% -40%, animal protein should be more than 25%, the other can add plant protein raw materials. General bait coefficient can reach between 0.8-1.2. The daily baiting amount is about 20% of the weight of the fish, and the baiting is done 3 times a day.