Method for rearing fries of Epinephelus lanceolatus

Abstract

The invention belongs to the technical field of aquaculture, and particularly relates to a pearl grouper fry rearing method. According to the method, firstly, after the roes are hatched, the fries are soaked with a bactericide, harmful bacteria on the surfaces of the roes and in a hatching pond can be effectively killed, and a bacteria solution of lactobacillus brevis serves as the bactericide, so that the use of antibiotics is reduced while the growth of pathogenic bacteria is inhibited; the culture pond is divided into 1m * 1m spaces by the partition plates, so that the phenomenon that the fries kill each other or snatch for food due to insufficient spaces is avoided, and uniform growth of the fries is facilitated; culture is carried out in stages according to nutritional requirements of different growth stages, and the Weissella microbial inoculum and the lactococcus lactis microbial inoculum are added to the feed in each stage, so that the intestinal microecological balance of the fry is adjusted, the growth and reproduction of harmful bacteria are inhibited, the intestinal digestion and absorption functions of the fry are enhanced, and the utilization rate of the feed is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of aquaculture, and in particular relates to a method for cultivating pearl grouper fry. Background Art

[0002] Pearl grouper (tiger-dragon hybrid grouper) is a new marine fish species bred by artificial breeding of grouper (male parent) and tiger grouper (female parent). It has the advantages of fast growth, strong adaptability, delicate meat, strong disease resistance, etc., and has broad market prospects. However, the survival rate of pearl grouper seedlings is generally low, which has become the main factor restricting its promotion and aquaculture. The main reasons are: (1) Water quality management is difficult. During the seedling raising process, factors such as water transparency, salinity, and temperature may cause the death of fry; (2) The phenomenon of residual food is serious. Pearl grouper is a carnivorous and ferocious fish with obvious predatory habits. It will actively attack and prey on smaller species; (3) The nutrition of feed is single: the nutrition structure of commonly used biological baits such as rotifers and artemia is single, which can easily lead to nutritional deficiencies in fry, affecting growth and disease resistance. Summary of the invention

[0003] The invention aims to provide a pearl grouper fry cultivation method to improve the survival rate of the fry and enhance the disease resistance of the fry.

[0004] The present invention provides a method for cultivating pearl grouper fry, comprising the following steps: The eggs of pearl grouper are placed in a hatching pool for hatching to obtain fry, and then a fungicide is added to the hatching pool, and the fry are transferred to a culture pool after soaking for 5 to 10 minutes, and the fry are fed with a first-stage feed and cultured in the first stage to obtain fry; the fry are fed with a second-stage feed and cultured in the second stage to obtain fingerlings; the fingerlings are fed with a third-stage feed and cultured in the third stage to obtain seedlings; the culture pool is divided into a space of 1 m×1 m by a partition; during the culture period, a fungicide is added to the culture pool once every 5 to 7 days, and the fungicide is a bacterial solution of Lactobacillus bread; the first-stage feed is 30 to 4 parts by weight of rotifers. 5 parts, 15-30 parts of Daphnia larvae, 20-30 parts of egg yolk powder, 30-45 parts of spirulina powder and 3-5 parts of lactococcus lactis inoculant; in parts by mass, the second stage feed is 30-45 parts of fish meal, 15-25 parts of Isochrysis algae powder, 5-10 parts of multivitamins, 3-5 parts of mineral powder, 1-3 parts of Weissella inoculant, and 1-3 parts of lactococcus lactis inoculant; in parts by mass, the third stage feed is 25-35 parts of fish meal, 20-35 parts of soybean meal, 20-30 parts of peanut bran, 5-10 parts of multivitamins, 3-5 parts of mineral powder, 1-3 parts of Weissella inoculant, and 1-3 parts of lactococcus lactis inoculant.

[0005] Preferably, the depth of the culture pond is 1-2 m.

[0006] Preferably, the dosage of the bactericide is 1-3 mg / L.

[0007] Preferably, the viable count of Lactobacillus panis in the bacterial liquid ≥ 1×10 10 CFU / mL.

[0008] Preferably, the hatching conditions are 25°C - 29°C, and the hatching time is 18 - 24 h.

[0009] Preferably, the stocking density of fry in the culture pond is 200 - 400 tails / m 2 .

[0010] Preferably, the culture conditions are 25°C - 35°C, the salinity is 15‰ - 40‰, and the light condition is 12 h light / 12 h dark natural light irradiation.

[0011] Preferably, the feeding frequency of the feed in the first stage is 4 - 6 times / day; the feeding frequency of the feed in the second stage is 6 - 8 times / day; the feeding frequency of the feed in the third stage is 6 - 8 times / day.

[0012] Preferably, the viable count of Weissella spp. in the bacterial agent ≥ 1×10 8 CFU / mL, and the viable count of Lactococcus lactis in the bacterial agent ≥ 1×10 8 CFU / mL.

[0013] Preferably, the first stage of culture is 20 - 30 days, the second stage of culture is 30 - 40 days, and the third stage of culture is 25 - 30 days.

[0014] Advantages of the present invention: The present invention provides a method for cultivating Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ fry. After the fish eggs are hatched, they are soaked in a bactericide, which can effectively kill harmful bacteria on the surface of the fish eggs and in the hatching pond, reduce the influence of pathogens on the fry, and create favorable conditions for subsequent growth and development; using the bacterial liquid of Lactobacillus panis as the bactericide can effectively inhibit the growth and reproduction of pathogenic bacteria in the culture pond, reduce the risk of fry infection with diseases, and also reduce the use of antibiotics, being more environmentally friendly and green. At the same time, Lactobacillus panis, as a beneficial bacterium, can also improve the water quality environment of the culture pond to a certain extent and promote the formation of a beneficial microbial community; when the fry ingest Lactobacillus panis during the culture process, it can also optimize the microbial community structure of the intestine, thereby improving the immunity of the fry.

[0015] According to the nutritional requirements of juvenile Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ at different growth stages, the present invention conducts cultivation in stages and feeds the fry with feed for the first stage, the second stage, and the third stage respectively at different stages, ensuring that the fry can obtain comprehensive and balanced nutrition at different growth stages, meeting their growth and development requirements for various nutrients, promoting the normal development of organs such as the fry's bones, muscles, and internal organs, and improving the growth rate and survival rate of the fry.

[0016] The Weissella bacterium agent and Lactococcus lactis bacterium agent added respectively to the feed in each stage of the present invention are beneficial to regulating the microecological balance of the fry's intestine, inhibiting the growth and reproduction of harmful bacteria, enhancing the intestinal digestion and absorption function of the fry, improving the utilization rate of the feed, and at the same time can also enhance the immunity of the fry, reduce the occurrence of diseases, and ensure the healthy growth of the fry during the whole cultivation process.

[0017] The cultivation pool is divided into 1m×1m spaces by partitions. This design not only ensures that the fry have enough activity space but also facilitates the grouped management of the fry, avoiding phenomena such as mutual cannibalism or food snatching among the fry due to insufficient space, which is beneficial to the uniform growth of the fry. At the same time, a reasonable cultivation pool depth (1 - 2m) can ensure the stability of water quality and good lighting conditions, providing a suitable environment for the growth of the fry.

[0018] By adjusting the feeding frequency, the present invention reduces the food competition behavior of the fry during the growth process and further reduces the occurrence of cannibalism phenomena. Detailed implementation mode

[0019] In order to further illustrate the present invention, the following describes in detail a method for cultivating juvenile Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ provided by the present invention in combination with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0020] The Lactobacillus panis used in the embodiments of the present invention is purchased from Fangjue Biology, product number HZB229202; the Weissella bacterium is purchased from Huizao Biology, Weissella halotolerans, product number HZB527461; the Lactococcus lactis is purchased from Runying Biology, model LLC - G42.

[0021] The substances used in the embodiments of the present invention are all conventional purchased products unless otherwise specified.

[0022] Example 1 Before cultivation, the hatching pool and the cultivation pool are exposed to the sun.

[0023] The depth of the cultivation pool is 1.8m, and the pool is divided into 1m×1m spaces by partitions; the eggs of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ are placed in the hatching pool and hatched at 28°C for 18h to obtain fry, and then Lactobacillus panis bacterium liquid (living bacteria count 1×10 10CFU / mL), transfer to the culture pond after soaking for 10 min, and the stocking density of fry is 200 tails / m 2 .

[0024] Feed the fry with the first-stage feed 5 times a day for 25 days to obtain juvenile fish; feed the juvenile fish with the second-stage feed 6 times a day for 30 days to obtain young fish; feed the young fish with the third-stage feed 8 times a day for 25 days to obtain seedlings; During the cultivation period, add Lactobacillus panis liquid (living bacteria count 1×10 10 CFU / mL) to the culture pond once every 7 days, and the dosage is 1 mg / L; By mass, the first-stage feed is 35 parts of rotifers, 20 parts of nauplii, 20 parts of egg yolk powder, 35 parts of spirulina powder and 3 parts of Lactococcus lactis inoculant (living bacteria count 1×10 8 CFU / mL); the second-stage feed is 40 parts of fish meal, 20 parts of Isochrysis galbana powder, 6 parts of compound vitamins, 3 parts of mineral powder, 2 parts of Weissella cibaria inoculant (living bacteria count 1×10 8 CFU / mL) and 2 parts of Lactococcus lactis inoculant (living bacteria count 1×10 8 CFU / mL); the third-stage feed is 30 parts of fish meal, 25 parts of soybean meal, 20 parts of peanut bran, 6 parts of compound vitamins, 3 parts of mineral powder, 2 parts of Weissella cibaria inoculant (living bacteria count 1×10 8 CFU / mL) and 2 parts of Lactococcus lactis inoculant (living bacteria count 1×10 8 CFU / mL).

[0025] Example 2 Before cultivation, expose the hatching pond and the culture pond to the sun.

[0026] The depth of the culture pond is 1.8 m, and the pond is divided into 1 m×1 m spaces by partitions; place the eggs of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ in the hatching pond, incubate at 28°C for 18 h to obtain fry, and then add Lactobacillus panis liquid (living bacteria count 1×10 10 CFU / mL) to the hatching pond, transfer to the culture pond after soaking for 10 min, and the stocking density of fry is 200 tails / m 2 .

[0027] Feed the fry with the first-stage feed 6 times a day for 20 days to obtain juvenile fish; feed the juvenile fish with the second-stage feed 8 times a day for 30 days to obtain young fish; feed the young fish with the third-stage feed 8 times a day for 25 days to obtain seedlings; During the cultivation period, add Lactobacillus panis liquid (living bacteria count 1×10 10 CFU / mL) to the culture pond once every 7 days, and the dosage is 1 mg / L; In parts by mass, the first-stage feed is 30 parts of rotifers, 30 parts of nauplii, 20 parts of egg yolk powder, 30 parts of spirulina powder, and 5 parts of Lactococcus lactis inoculant (viable cell count 1×10 8 CFU / mL); the second-stage feed is 40 parts of fish meal, 20 parts of Isochrysis galbana powder, 8 parts of compound vitamins, 3 parts of mineral powder, 2 parts of Weissella cibaria inoculant (viable cell count 1×10 8 CFU / mL), and 2 parts of Lactococcus lactis inoculant (viable cell count 1×10 8 CFU / mL); the third-stage feed is 30 parts of fish meal, 25 parts of soybean meal, 20 parts of peanut bran, 8 parts of compound vitamins, 3 parts of mineral powder, 1 part of Weissella cibaria inoculant (viable cell count 1×10 8 CFU / mL), and 2 parts of Lactococcus lactis inoculant (viable cell count 1×10 8 CFU / mL).

[0028] Example 3 Before culturing, the hatching pond and the culture pond are exposed to the sun.

[0029] The depth of the culture pond is 1.8 m, and the pond is divided into 1 m×1 m spaces by partitions; the eggs of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ are placed in the hatching pond and hatched at 28°C for 18 h to obtain fry. Then, Lactobacillus panis bacterium solution (viable cell count 1×10 10 CFU / mL) is added to the hatching pond. After soaking for 10 min, the fry are transferred to the culture pond, and the stocking density of the fry is 200 tails / m 2 .

[0030] The fry are fed with the first-stage feed 6 times a day for 20 days to obtain larvae; the larvae are fed with the second-stage feed 8 times a day for 30 days to obtain juveniles; the juveniles are fed with the third-stage feed 8 times a day for 25 days to obtain seedlings; During the culturing period, Lactobacillus panis bacterium solution (viable cell count 1×10 10 CFU / mL) is added to the culture pond once every 7 days, and the dosage is 1 mg / L; In parts by mass, the first-stage feed is 30 parts of rotifers, 30 parts of nauplii, 20 parts of egg yolk powder, 30 parts of spirulina powder, and 5 parts of Lactococcus lactis inoculant (viable cell count 1×10 8 CFU / mL); the second-stage feed is 40 parts of fish meal, 20 parts of Isochrysis galbana powder, 8 parts of compound vitamins, 3 parts of mineral powder, 2 parts of Weissella cibaria inoculant (viable cell count 1×10 8 CFU / mL), and 2 parts of Lactococcus lactis inoculant (viable cell count 1×10 8 CFU / mL); the third-stage feed is 30 parts of fish meal, 25 parts of soybean meal, 20 parts of peanut bran, 8 parts of compound vitamins, 3 parts of mineral powder, 1 part of Weissella cibaria inoculant (viable cell count 1×108 2 parts of Lactococcus lactis agent (viable count 1×10 8 CFU / mL) and 1 part of Lactococcus lactis agent (viable count 1×10

[0031] Comparative Example 1 It is different from Example 1 in that potassium permanganate is used as a bactericide, specifically as follows: Before culturing, the hatching pond and the culture pond are exposed to the sun.

[0032] The depth of the culture pond is 1.8 m, and the pond is divided into 1 m×1 m spaces by partitions; the eggs of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ are placed in the hatching pond and hatched at 28°C for 18 h to obtain fry, then potassium permanganate (2 g / L) is added to the hatching pond, and after soaking for 10 min, they are transferred to the culture pond, and the stocking density of the fry is 200 tails / m 2 .

[0033] The fry are fed with the first-stage feed, 5 times a day for 25 days to obtain juvenile fish; the juvenile fish are fed with the second-stage feed, 6 times a day for 30 days to obtain young fish; the young fish are fed with the third-stage feed, 8 times a day for 25 days to obtain seedlings; During the culturing period, potassium permanganate (2 g / L) is added to the culture pond once every 7 days; By mass, the first-stage feed is 35 parts of rotifers, 20 parts of nauplii, 20 parts of egg yolk powder, 35 parts of spirulina powder and 3 parts of Lactococcus lactis agent (viable count 1×10 8 CFU / mL); the second-stage feed is 40 parts of fish meal, 20 parts of Isochrysis galbana powder, 6 parts of compound vitamin, 3 parts of mineral powder, 2 parts of Weissella cibaria agent (viable count 1×10 8 CFU / mL) and 2 parts of Lactococcus lactis agent (viable count 1×10 8 CFU / mL); the third-stage feed is 30 parts of fish meal, 25 parts of soybean meal, 20 parts of peanut bran, 6 parts of compound vitamin, 3 parts of mineral powder, 2 parts of Weissella cibaria agent (viable count 1×10 8 CFU / mL) and 2 parts of Lactococcus lactis agent (viable count 1×10 8 CFU / mL).

[0034] Comparative Example 2 It is different from Example 1 in that only Lactococcus lactis is used as the probiotic in the feed, specifically as follows: The depth of the culture pond is 1.8 m, and the pond is divided into 1 m×1 m spaces by partitions; the eggs of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ are placed in the hatching pond and hatched at 28°C for 18 h to obtain fry, then Lactobacillus crustorum liquid (viable count 1×10 10CFU / mL), transfer them to the culture pond after soaking for 10 min, and the breeding density of fry is 200 tails / m 2 .

[0035] Feed the fry with the first-stage feed, feeding 5 times a day for 32 days to obtain juvenile fish; feed the juvenile fish with the second-stage feed, feeding 6 times a day for 35 days to obtain young fish; feed the young fish with the third-stage feed, feeding 8 times a day for 30 days to obtain seedlings; During the cultivation period, add Lactobacillus crustorum bacterial liquid (living bacteria count 1×10 10 CFU / mL) to the culture pond once every 7 days, and the dosage is 1 mg / L; By mass, the first-stage feed is 35 parts of rotifers, 20 parts of nauplii, 20 parts of egg yolk powder, 35 parts of spirulina powder and 3 parts of Lactococcus lactis bacterial agent (living bacteria count 1×10 8 CFU / mL); the second-stage feed is 40 parts of fish meal, 20 parts of Isochrysis galbana powder, 6 parts of compound vitamins, 3 parts of mineral powder and 4 parts of Lactococcus lactis bacterial agent (living bacteria count 1×10 8 CFU / mL); the third-stage feed is 30 parts of fish meal, 25 parts of soybean meal, 20 parts of peanut bran, 6 parts of compound vitamins, 3 parts of mineral powder and 4 parts of Lactococcus lactis bacterial agent (living bacteria count 1×10 8 CFU / mL).

[0036] Comparative Example 3 The difference from Example 1 is that Weissella is only used as the probiotic in the feed, as follows: The depth of the culture pond is 1.8 m, and the pond is partitioned into 1 m×1 m spaces with partitions; place the eggs of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ in the hatching pond and incubate at 28°C for 18 h to obtain fry, then add Lactobacillus crustorum bacterial liquid (living bacteria count 1×10 10 CFU / mL) to the hatching pond, transfer them to the culture pond after soaking for 10 min, and the breeding density of fry is 200 tails / m 2 .

[0037] Feed the fry with the first-stage feed, feeding 5 times a day for 25 days to obtain juvenile fish; feed the juvenile fish with the second-stage feed, feeding 6 times a day for 44 days to obtain young fish; feed the young fish with the third-stage feed, feeding 8 times a day for 30 days to obtain seedlings; During the cultivation period, add Lactobacillus crustorum bacterial liquid (living bacteria count 1×10 10 CFU / mL) to the culture pond once every 7 days, and the dosage is 1 mg / L; By mass, the first-stage feed is 35 parts of rotifers, 20 parts of nauplii, 20 parts of egg yolk powder, 35 parts of spirulina powder and 3 parts of Weissella bacterial agent (living bacteria count 1×10 83 parts of (CFU / mL); The second-stage feed is 40 parts of fish meal, 20 parts of Isochrysis galbana powder, 6 parts of compound vitamins, 3 parts of mineral powder, Weissella bacterium agent (viable count 1×10 8 CFU / mL) 4 parts; The third-stage feed is 30 parts of fish meal, 25 parts of soybean meal, 20 parts of peanut bran, 6 parts of compound vitamins, 3 parts of mineral powder, Weissella bacterium agent (viable count 1×10 8 CFU / mL) 4 parts.

[0038] Comparative Example 4 The difference from Example 1 is that the culture pond is not provided with a partition board, specifically as follows: Before culturing, the hatching pond and the culture pond are exposed to the sun.

[0039] The depth of the culture pond is 1.8 m. The eggs of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ are placed in the hatching pond and hatched at 28 °C for 18 h to obtain fry. Then, Lactobacillus panis bacterium liquid (viable count 1×10 10 CFU / mL) is added to the hatching pond. After soaking for 10 min, they are transferred to the culture pond, and the stocking density of the fry is 200 tails / m 2 .

[0040] The fry are fed with the first-stage feed 5 times a day for 25 days to obtain juvenile fish; the juvenile fish are fed with the second-stage feed 6 times a day for 35 days to obtain young fish; the young fish are fed with the third-stage feed 8 times a day for 25 days to obtain seedlings; During the culturing period, Lactobacillus panis bacterium liquid (viable count 1×10 10 CFU / mL) is added to the culture pond once every 7 days, and the dosage is 1 mg / L; In terms of parts by mass, the first-stage feed is 35 parts of rotifers, 20 parts of nauplii, 20 parts of egg yolk powder, 35 parts of Spirulina powder, and Lactococcus lactis bacterium agent (viable count 1×10 8 CFU / mL) 3 parts; The second-stage feed is 40 parts of fish meal, 20 parts of Isochrysis galbana powder, 6 parts of compound vitamins, 3 parts of mineral powder, Weissella bacterium agent (viable count 1×10 8 CFU / mL) 2 parts, Lactococcus lactis bacterium agent (viable count 1×10 8 CFU / mL) 2 parts; The third-stage feed is 30 parts of fish meal, 25 parts of soybean meal, 20 parts of peanut bran, 6 parts of compound vitamins, 3 parts of mineral powder, Weissella bacterium agent (viable count 1×10 8 CFU / mL) 2 parts, Lactococcus lactis bacterium agent (viable count 1×10 8 CFU / mL) 2 parts.

[0041] Comparative Example 5 The difference from Example 1 is that the feeding frequency of each stage of feed is reduced, specifically as follows: Before culturing, expose the hatching pond and the culturing pond to the sun.

[0042] The depth of the culturing pond is 1.8 m, and the pond is divided into 1 m × 1 m spaces by partitions; place the eggs of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ in the hatching pond, incubate at 28 °C for 18 h to obtain fry, then add the liquid of Lactobacillus alimentarius (viable count 1×10 10 CFU / mL) to the hatching pond, soak for 10 min and then transfer to the culturing pond, and the stocking density of the fry is 200 tails / m 2 .

[0043] Feed the fry with the first-stage feed 3 times a day for 25 days to obtain juvenile fish; feed the juvenile fish with the second-stage feed 3 times a day for 35 days to obtain young fish; feed the young fish with the third-stage feed 4 times a day for 25 days to obtain seedlings; During the culturing period, add the liquid of Lactobacillus alimentarius (viable count 1×10 10 CFU / mL) to the culturing pond once every 7 days, and the dosage is 1 mg / L; By mass, the first-stage feed is 35 parts of rotifers, 20 parts of nauplii, 20 parts of egg yolk powder, 35 parts of spirulina powder and 3 parts of Lactococcus lactis agent (viable count 1×10 8 CFU / mL); the second-stage feed is 40 parts of fish meal, 20 parts of Isochrysis galbana powder, 6 parts of compound vitamins, 3 parts of mineral powder, 2 parts of Weissella cibaria agent (viable count 1×10 8 CFU / mL) and 2 parts of Lactococcus lactis agent (viable count 1×10 8 CFU / mL); the third-stage feed is 30 parts of fish meal, 25 parts of soybean meal, 20 parts of peanut bran, 6 parts of compound vitamins, 3 parts of mineral powder, 2 parts of Weissella cibaria agent (viable count 1×10 8 CFU / mL) and 2 parts of Lactococcus lactis agent (viable count 1×10 8 CFU / mL).

[0044] Comparative Example 6 The difference from Example 1 is that conventional feeds are fed in each stage, specifically as follows: Before culturing, expose the hatching pond and the culturing pond to the sun.

[0045] The depth of the culturing pond is 1.8 m, and the pond is divided into 1 m × 1 m spaces by partitions; place the eggs of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ in the hatching pond, incubate at 28 °C for 18 h to obtain fry, then add the liquid of Lactobacillus alimentarius (viable count 1×10 10 CFU / mL) to the hatching pond, soak for 10 min and then transfer to the culturing pond, and the stocking density of the fry is 200 tails / m 2 .

[0046] Feed the fry with the first-stage feed 5 times a day for 30 days to obtain fingerlings; feed the fingerlings with the second-stage feed 6 times a day for 45 days to obtain juveniles; feed the juveniles with the third-stage feed 8 times a day for 35 days to obtain seedlings; During the cultivation period, add the Lactobacillus panis bacterial liquid (the viable count is 1×10 10 CFU / mL) to the cultivation pool once every 7 days, and the dosage is 1 mg / L; The first-stage feed is rotifers; the second-stage and third-stage feeds are conventional commercially available fry feeds.

[0047] Test Example 1 Observe whether cannibalism occurs during the growth process of the fry in Examples 1 to 3 and Comparative Examples 1 to 6, count the morbidity rate of the fry (morbidity rate = number of diseased individuals / total number of fry), compare the growth cycles of the fry in each group (the time from fry to seedlings), and randomly select 100 seedlings from each group for weighing and measurement, and count the average weight and average body length. The results are shown in Table 1.

[0048] Table 1 Statistical results of the growth of seedlings

[0049] As can be seen from Table 1, compared with Examples 1 to 3, cannibalism occurred in the fry in Comparative Examples 4 and 5, indicating that when the fry are unevenly distributed or the feeding frequency is low, fry competition for food will occur and the cannibalism behavior is more serious. The morbidity rate of the fry in Comparative Example 1 is higher than that in the Examples, indicating that the present invention uses the Lactobacillus panis bacterial liquid as a bactericide, and its inhibitory effect on pathogens is better than that of traditional potassium permanganate; combining Comparative Examples 2 and 3, it can be seen that the combined use of Weissella and Lactococcus lactis in the feed can produce a synergistic effect. Compared with using only one of the bacterial agents alone, the compounding of two bacterial agents in the feed is more conducive to shortening the seedling raising cycle and improving the feed utilization rate. Comparing Example 1 and Comparative Example 6, it can be seen that the growth cycle of the seedlings in Example 1 is shorter and the morbidity rate is lower. The feed provided by the present invention is more conducive to shortening the growth cycle of Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂ seedlings and improving the immunity of the fry.

[0050] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, rather than all embodiments. People can also obtain other embodiments based on these embodiments without creative efforts, and these embodiments all belong to the protection scope of the present invention.

Claims

1. A method for breeding pearl grouper fry, characterized in that: The following steps are involved: The eggs of pearl grouper are placed in a hatching pool for hatching to obtain fry, and then a fungicide is added to the hatching pool, and the eggs are transferred to a culture pool after soaking for 5 to 10 minutes, and the eggs are fed with a first-stage feed, and the eggs are cultured in the first stage to obtain fry; the eggs are fed with a second-stage feed, and the eggs are cultured in the second stage to obtain fingerlings; the fingerlings are fed with a third-stage feed, and the fingerlings are cultured in the third stage to obtain seedlings; The culture pool is divided into a space of 1m×1m by a partition; During the culture period, a bactericide is added to the culture tank once every 5 to 7 days, wherein the bactericide is a bacterial solution of Lactobacillus bread; In parts by mass, the first-stage feed is 30-45 parts of rotifers, 15-30 parts of Daphnia larvae, 20-30 parts of egg yolk powder, 30-45 parts of spirulina powder and 3-5 parts of Lactococcus lactis agent; In parts by mass, the second stage feed is 30-45 parts of fish meal, 15-25 parts of Isochrysis algae powder, 5-10 parts of multivitamins, 3-5 parts of mineral powder, 1-3 parts of Weissella inoculum, and 1-3 parts of Lactococcus lactis inoculum; In parts by mass, the third stage feed is 25-35 parts of fish meal, 20-35 parts of soybean meal, 20-30 parts of peanut bran, 5-10 parts of multivitamins, 3-5 parts of mineral powder, 1-3 parts of Weissella inoculant, and 1-3 parts of Lactococcus lactis inoculant.

2. The method according to claim 1, characterized in that The culture pool has a depth of 1 to 2 m.

3. The method according to claim 1, characterized in that The dosage of the bactericide is 1-3 mg / L.

4. The method according to claim 1, characterized in that: The number of viable Lactobacillus in the bacterial solution is ≥ 1×10 10 CFU / mL.

5. The method according to claim 1, characterized in that The incubation condition is 25°C to 29°C, and the incubation time is 18 to 24 hours.

6. The method according to claim 1, characterized in that The culture density of the fry in the culture pond is 200-400 fry / m 2 .

7. The method according to claim 1, characterized in that The culture conditions are 25°C to 35°C, salinity 15‰ to 40‰, and lighting conditions are 12h light / 12h dark natural light irradiation.

8. The method according to claim 1, characterized in that The feeding frequency of the first-stage feed is 4 to 6 times per day; the feeding frequency of the second-stage feed is 6 to 8 times per day; and the feeding frequency of the third-stage feed is 6 to 8 times per day.

9. The method according to claim 1, characterized in that: The number of viable bacteria in the Weissella inoculum is ≥ 1×10 8 CFU / mL, the number of viable bacteria in the Lactococcus lactis agent is ≥ 1×10 8 CFU / mL.

10. The method according to claim 1, characterized in that The first stage is cultured for 20 to 30 days, the second stage is cultured for 30 to 40 days, and the third stage is cultured for 25 to 30 days.

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