Breeding method for improving sebastes schlegeli fry quality

Abstract

The invention discloses a culture method for improving sebastes schlegeli fry quality, which comprises the following steps: collecting sebastes schlegeli breeder seed fields in advance, artificially breeding parents by using net cages on the sea, performing nutrition rejuvenation on the parents, and obtaining offspring fry by using a method of manually squeezing fry; reasonable culture density is controlled according to different seedling specifications, and natural plant active ingredients easy to absorb are screened to be matched with common microecologics and the like for use, so that disinfection and drug use are avoided; controlling the flowing speed of aquaculture water in different growth stages. The method integrates nutrition rejuvenation, artificial farrowing, pollution-free water quality regulation and control and offspring seed behavior state regulation and control, solves the problems that parent germplasm is poor, dead offspring seeds or offspring seed activity is insufficient, growth is slow, stress resistance is poor and the like in the offspring seed breeding process, and is high in operation controllability in the breeding period, high in offspring seed survival rate and remarkable in growth promoting immune effect; the method has good prevention and treatment effects on bacterial diseases, realizes pollution-free seedling breeding, can reduce disease occurrence and death rate, reduces feed coefficient, and effectively improves culture economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture, and more particularly to a breeding method for improving the quality of fry of Scorpionfish philadelphus. Background Art

[0002] Sebastesschlegelii is also known as black croaker, black fish, thorn hair, and black village. It belongs to the order Scorpionfish, family Scorpionidae, and genus Scorpionfish. This fish has high nutritional value, few bones, and is delicious. It is available on the market around the Spring Festival and monopolizes the seafood market. It is expensive. In recent years, in order to alleviate the decreasing natural resources of Sebastesschlegelii, the reproduction and release of Sebastesschlegelii has been gradually carried out, building "marine ranches" and creating "undersea forests", carrying out bottom seeding and reproduction of fish, developing recreational fisheries and ecological fisheries, benefiting future generations, and promoting the sustainable development of the fishery economy, which has very significant economic, social and ecological benefits.

[0003] With the decline of marine fishery resources and the continuous decline of marine fishing production efficiency, more and more fishery producers in various countries around the world have set their sights on factory farming, which has promoted the rise of the fish factory farming industry. Among them, the flatfish is very popular among producers and consumers in various countries because of its delicious taste and rich nutrition. At present, many countries in the world have widely carried out the breeding and production of flatfish and the development of seedlings. my country's aquaculture industry is developing rapidly, and fish factory farming is constantly moving towards a new level, but the breeding of marine fish is mostly concentrated on turbot, flounder, large yellow croaker and sea bass. The flatfish is a kind of island reef cold-water fish, with Changdao Miaodao Islands as the main production area. It has tender meat, delicious taste, high market price, and a broad market space. Its development and promotion are of great and far-reaching significance for restoring marine ecological resources and developing regional characteristic economy. Summary of the invention

[0004] In view of this, the present invention provides a breeding method for improving the quality of Xu's flatfish seedlings in artificial breeding, reducing the occurrence of diseases and mortality, lowering the feed coefficient, and effectively improving the economic benefits of breeding.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A method for improving the quality of fry of Scorpionfish, comprising the following steps:

[0007] Step 1: Select a farm and adjust the quality of water used for breeding;

[0008] Step 2: Select the parent species of Xu's flathead scorpionfish;

[0009] Select active and healthy 2-year-old mature parents that were artificially bred and cultured in cages at sea at Xu's flatfish original breeding farm in advance;

[0010] Step 3: Breeding of the parent stock of Xu's flathead scorpionfish;

[0011] The parents after the breeding treatment in step 2 are placed in a culture pond in a ratio of female to male = 1:1, and after the parents mate, the fertilized female fish are taken out and placed in a breeding pond to wait for birth, and after birth, the newly hatched seedlings are placed in a seedling cultivation pond for cultivation;

[0012] Step 4: Seedling breeding

[0013] (4.1) Control the stocking density, that is:

[0014] When the seedlings are fry with a length of ≤1cm, the stocking density is 2000-2500 / m 3 ;

[0015] When the fry are fry with a length of >1cm and ≤3cm, the stocking density is 1500-2000 / m 3 ;

[0016] When the fry are fry with a length of >3cm and ≤5cm, the stocking density is 1000-1500 / m 3 ;

[0017] When the fry are fry with a length of >5cm and ≤8cm, the stocking density is 700-800 / m 3 ;

[0018] When the length of the seedlings is greater than 8 cm, the stocking density is 500-600 / m 3 .

[0019] (4.2) Feeding of seedlings, namely:

[0020] Feed the seedlings with rotifers on the 1st to 15th day after birth, and sprinkle fresh Chlorella until the water body has a slight algae color;

[0021] Feed the seedlings with rotifers and Artemia nauplii on the 15th to 30th day after birth, and sprinkle fresh Chlorella until the water body has a slight algae color;

[0022] Feed the seedlings with Artemia nauplii and sea urchin fry feed (particle size 0.25-0.36mm) on the 30th to 45th day after birth, and sprinkle or mix with microecological preparations, feed additives and disease control drugs;

[0023] Feed the seedlings with a suitable particle size of compound feed for sea urchin fry and fry when they are ≥45 days old, and sprinkle or mix the feed with microecological preparations, feed additives and disease prevention drugs;

[0024] (4.3) Control the light in the culture environment, that is:

[0025] The intensity of the illumination is below 1000 Lx, and the illumination cycle is light:dark=12h:12h;

[0026] (4.4) Control the culture environment, namely:

[0027] The water temperature for aquaculture is 17℃~25℃, of which the water temperature in spring is ≥17℃ and the water temperature in summer is ≤25℃;

[0028] The salinity of the water used in the farm is 25‰~32‰, the pH is 7.8~8.3, and the dissolved oxygen content is ≥5mg / L. The pond is emptied once a month. Before emptying the pond, astaxanthin is used for 5 consecutive days at a dosage of 10mL / kg mixed with feed. Before and after emptying the pond, astaxanthin feeding is stopped and VC Yingjiling is sprayed at a dosage of 0.5g / m 3 .

[0029] Preferably, the aquaculture farm in step 1 is located around a sea area with smooth and pollution-free sea flow and convenient transportation; the water quality of aquaculture water meets the requirements of NY5052-2001 for water quality of pollution-free food seawater aquaculture.

[0030] Preferably, the parent size in step 2 is ≥ 2 kg, the temperature of the parent breeding sea area is 13° C., and fresh frozen small fish and small shrimp are fed during breeding.

[0031] Preferably, the density of the fertilized female fish in the breeding pond in step 3 is 1 fish / m 3 , the output process is:

[0032] Select female fish that are about to give birth, wrap the fish body with a cloth soaked in seawater and cover the eyes of the female fish, gently squeeze the fish abdomen towards the reproductive opening, and the mature fry will slowly flow into the pre-prepared water tank. Stop squeezing the fry after the outflow speed of the fry slows down, put the parent fish back into the pond and mark the net cage, and squeeze the fry again after 2 to 4 hours until the birth is completed;

[0033] The culture pool contains naturally filtered seawater at a temperature of 13°C. The temperature is raised by 0.5°C per day during the culture period and is temporarily maintained at a constant temperature when the temperature reaches 17°C.

[0034] Preferably, in step (4.2), the feeding amount of rotifers is 6 to 8 per mL, and the feeding amount of Artemia nauplii is 3 to 5 per mL according to the volume of the culture water body;

[0035] The microecological preparation, feed additive, disease prevention and control medicine and use method are:

[0036] Brown sugar-free EM probiotics once a week, 3-5g / m 3; 0.2% multivitamin, once a week, diluted 2g / kg feed each time; bile acid is used at a dosage of 4-6g / kg feed each time, once a week for prevention, and used for 5 consecutive days for treatment; poplar flower essence, 10mL / kg each time, mixed with enteritis killer 5g / kg feed, once a week for prevention, and used for 3-5 consecutive days for treatment;

[0037] When the seedlings are ≤2cm in length, feed them 4 to 5 times a day; when the seedlings are >2cm in length, feed them 2 to 3 times a day.

[0038] Preferably, the daily fresh seawater replacement rate is 50% on the 1st to 15th day after the seedlings are born; the daily fresh seawater replacement rate is 50% to 100% on the 15th to 45th day after the seedlings are born; and after the 46th day after the seedlings are born, fresh seawater is used for constant flow culture.

[0039] Furthermore, in the constant flow aquaculture of fresh seawater, the flow rate is controlled at 1 BL / s.

[0040] Preferably, the rotifers and Artemia nauplii in step (4.2) are subjected to nutritional enrichment treatment before being fed.

[0041] Furthermore, the culturing method of rotifers comprises the following steps:

[0042] The culture density is 500 cells / mL, the water temperature is 28℃, the salinity is 28-30, the pH is 8.0-8.4, the light intensity is 1000Lx, and sufficient aeration is used to maintain the dissolved oxygen content of the water above 5mg / L;

[0043] The enhancer for the rotifer nutritional enhancement treatment is Schizochytrium powder, the dosage is 0.25 g / L based on the volume of the water body, and the nutritional enhancement time is 12 hours;

[0044] The method for cultivating Artemia nauplii comprises the following steps:

[0045] The culture density was 150 cells / mL, the water temperature was 28°C, the salinity was 28-30, the pH was 8.0-8.4, the light intensity was 1000Lx, and there was sufficient aeration;

[0046] The enhancer for the Artemia salina nutritional enhancement treatment includes Schizochytrium powder, the amount of the enhancer is 0.4 g / L based on the volume of the water body, and the nutritional enhancement time is 12 hours.

[0047] Preferably, in step (4.2), when the seedlings are fed with rotifers and Artemia nauplii 15 to 30 days after birth, the feeding method of the rotifers and Artemia nauplii is: feeding rotifers normally, reducing the amount of rotifers fed in the afternoon, supplementing with a small amount of Artemia nauplii, and gradually advancing the feeding time of Artemia nauplii and increasing the feeding amount of Artemia nauplii in the later stage until the feeding of rotifers is stopped;

[0048] Specifically: from 15 to 20 days, the amount of rotifers fed in the afternoon is reduced by 1 / ml, and the amount of Artemia fed is increased by 1 / ml; from 20 to 25 days, the amount of rotifers fed in the afternoon is reduced by 2 / ml, and the amount of Artemia fed is increased by 2 / ml; from 25 to 30 days, the amount of rotifers fed is 0, and the amount of Artemia fed is 5 / ml;

[0049] When the seedlings are fed with Artemia nauplii and compound feeds at 30 to 45 days after birth, the feeding method of Artemia nauplii and compound feeds is: feeding Artemia nauplii normally, reducing the feeding amount of Artemia nauplii in the afternoon, supplementing with a small amount of compound feeds, and gradually advancing the feeding time of compound feeds and increasing the feeding amount of compound feeds in the later stage until the feeding of Artemia nauplii is stopped, specifically:

[0050] On the 30th to 35th day, the Artemia feeding amount is reduced by 1 / ml in the afternoon. On the 35th to 40th day, the Artemia feeding amount is reduced by 2 / ml in the afternoon. On the 40th to 45th day, the Artemia feeding amount is 0. Feed the compound feed in small amounts and multiple times according to the degree of fullness.

[0051] Preferably, when the water temperature is greater than 25°C, the feed is halved, and the remaining bait and feces are siphoned off 2 hours after each feeding; the light, water temperature, salinity and other environmental factors are kept stable to prevent the occurrence of stress reactions, and the diseased and dead individuals in the breeding pond are cleaned up in time.

[0052] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a method for cultivating fish fry to improve the quality of fish fry, which has the following beneficial effects:

[0053] The breeding method provided by the present invention collects the parents from the original breeding farm of Xu's flatfish in advance, artificially cultivates the parents in cages at sea and rejuvenates the parents with nutrition, and obtains the offspring seedlings by using the artificial squeezing method. The number of fry can be regulated according to production, and the problems of dystocia and abortion of the parent fish in the first reproduction can be avoided, the inconvenience of manual operation can be reduced and the density of the breeding pond can be controlled; the method of selecting the combination of easily absorbed natural plant active ingredients and common microecological preparations can be used to avoid disinfection and drug use, thereby improving the quality of Xu's flatfish seedlings and the health of their diet; the flow rate of the breeding water body at different growth stages is controlled to ensure that the flatfish exhibits a more natural behavior ability and obtain the best growth performance. The method integrates nutritional rejuvenation, artificial birthing, pollution-free water quality control and seedling behavior state control, and focuses on solving the technical problems of poor parental germplasm, dead seedlings or insufficient seedling activity, slow growth and poor stress resistance in the breeding process of Xu's flatfish seedlings. The operation during the breeding period is highly controllable, the survival rate of the seedlings is high, the use of microecological probiotics and the control of water flow rate have significant growth-promoting and immune effects, and it has good prevention and control effects on bacterial diseases, realizes pollution-free seedling breeding, can reduce disease occurrence and mortality, reduce feed coefficient, and effectively improve the economic benefits of aquaculture. DETAILED DESCRIPTION

[0054] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] The following examples and comparative examples all took place from May to July.

[0056] Example 1

[0057] Step 1: The farm should be located in an area with smooth and pollution-free sea flow and convenient transportation. The water quality of aquaculture water should meet the requirements of NY5052-2001 for pollution-free food seawater aquaculture water quality.

[0058] Step 2: Select parents:

[0059] The parent fish of Xu's flatfish are selected and nourished by being temporarily raised in filtered seawater at 13°C with fresh frozen small fish and shrimp for more than one month. After temporary raising, the individuals with uniform size, normal body color, no damage on the body surface, no disease or deformity, strong activity and good feeding condition are selected;

[0060] Step 3: Parent breeding

[0061] The male and female parents of the broodstock fish that have been raised in step 2 are placed in a breeding pond at a ratio of 1:1. After the parents mate, the fertilized female broodstock are taken out and placed in a breeding pond to give birth (1 fish / m 3 ), after production, the newly hatched seedlings are placed in a seedling cultivation pool for cultivation;

[0062] The culture pool contains naturally filtered seawater at a temperature of 13°C. The temperature is raised by 0.5°C every day during the culture period and is temporarily kept at a constant temperature when it reaches 17°C.

[0063] Fresh frozen small fish and shrimp are fed to the breeding pond, while the female fish waiting to give birth in the breeding pond are not fed;

[0064] The female fish waiting to give birth in the breeding pond lies quietly in the dark at the bottom of the pond, with their heads often facing downwards, and their pectoral, pelvic and caudal fins swaying slowly; select the female fish that is about to give birth, wrap the fish body with a cloth soaked in seawater and cover the female fish's eyes, gently squeeze the fish's abdomen in the direction of the reproductive opening, and the mature fry slowly flow into the circular water tank prepared in advance; then gently squeeze the abdomen of the parent fish until the outflow speed of the fry slows down, stop squeezing the fry, put the parent fish back into the pond and mark the net cage, and squeeze the fry again after 2 to 4 hours according to production needs;

[0065] Step 4: Seedling breeding

[0066] (4.1) Adjust the stocking density in time according to the size of the seedlings. The stocking density is:

[0067] ≤1cm seedlings 2500 / m 3 ;

[0068] 2000 seedlings / m 3 ;

[0069] 1500 fry / m3 of 3-5cm 3 ;

[0070] 5~8cm seedlings 700 / m 3 ;

[0071] 500 scorpionfish larger than 8cm / m 3 ;

[0072] During the cultivation period, the individuals with uneven growth and size are selected and cultivated in separate ponds to ensure uniform specifications of seedlings in the same breeding pond;

[0073] (4.2) Feeding of seedlings, namely:

[0074] Feed rotifers on the 1st to 15th day of hatching fry, sprinkle fresh Chlorella until the water body shows a slight algae color, and replace the water with 50% fresh seawater every day;

[0075] From the 15th to the 30th day, feed rotifers and Artemia nauplii, sprinkle fresh Chlorella until the water body shows a slight algae color, and replace the water with 50% fresh seawater every day;

[0076] The feeding method of rotifers and Artemia nauplii is: feed rotifers normally, reduce the amount of rotifers in the afternoon, and feed Artemia nauplii in small amounts. In the later stage, the feeding time of Artemia nauplii is gradually advanced and the amount of Artemia nauplii is increased until the feeding of rotifers is stopped.

[0077] Specifically: from 15 to 20 days, the amount of rotifers fed in the afternoon is reduced by 1 / ml, and the amount of Artemia fed is increased by 1 / ml; from 20 to 25 days, the amount of rotifers fed in the afternoon is reduced by 2 / ml, and the amount of Artemia fed is increased by 2 / ml; from 25 to 30 days, the amount of rotifers fed is 0, and the amount of Artemia fed is 5 / ml;

[0078] From the 30th to the 45th day, feed Artemia nauplii and sea urchin fry feed (particle size 0.25-0.36mm), sprinkle or mix with microecological preparations, feed additives and disease prevention drugs, and change the water volume by 50%-100% every day;

[0079] The feeding method of Artemia nauplii and compound feed is: feed Artemia nauplii normally, reduce the amount of Artemia nauplii in the afternoon, feed a small amount of compound feed, gradually advance the feeding time of compound feed and increase the amount of compound feed in the later stage, until the feeding of Artemia nauplii is stopped. Specifically:

[0080] On the 30th to 35th day, the Artemia feeding amount is reduced by 1 / ml in the afternoon. On the 35th to 40th day, the Artemia feeding amount is reduced by 2 / ml in the afternoon. On the 40th to 45th day, the Artemia feeding amount is 0. Feed the compound feed in small amounts and multiple times according to the degree of fullness.

[0081] After the 45th day, feed the fry feed of suitable particle size, sprinkle or mix the feed with microecological preparations, feed additives and disease prevention drugs, and cultivate in fresh seawater.

[0082] The above baits are rinsed clean and free of pathogens;

[0083] Usage of probiotics, feed additives and disease control drugs: Brown sugar-free EM probiotics once a week, 3-5g / m 3 ; 0.2% multivitamin, once a week, diluted to 2g / kg feed for feeding; bile acid is used at a dosage of 4-6g / kg feed each time, once a week for prevention, and used for 5 consecutive days for treatment; poplar flower essence, 10mL / kg each time, mixed with enteritis killer 5g / kg feed for feeding, once a week for prevention, and used for 3-5 consecutive days for treatment;

[0084] When the seedlings are ≤2cm in length, feed them 4-5 times a day in small amounts. When they are >2cm in length, they are phototropic and tend to be phototropic. Feed them 2-3 times a day in concentrated amounts.

[0085] In the above-mentioned constant flow water culture using fresh seawater, the flow rate of the constant flow water is adjusted according to the actual body length of the seedlings, and the flow rate is controlled to be 1BL / s;

[0086] Rotifers are fed at 5 / mL of culture water, and Artemia nauplii are fed at 3-5 / mL. Nutritional fortification is required before feeding.

[0087] The rotifer enhancer is Schizochytrium powder; the culture density of rotifers is 500 / ml, the amount of enhancer is 0.25g / L (water volume), the enhancement is 12h, the water temperature is about 28℃, the salinity is 28-30, the pH is 8.0-8.4, the light intensity is about 1000Lx, and the water is aerated enough to keep the dissolved oxygen content of the water above 5mg / L;

[0088] The Artemia nauplii enhancer is Schizochytrium powder, the culture density of Artemia nauplii is 150 / ml, the amount of enhancer is 0.4g / L (water volume), the enhancement is 12h, the water temperature is about 28℃, the salinity is 28-30, the pH is 8.0-8.4, the light intensity is about 1000Lx, and sufficient aeration is used to maintain the dissolved oxygen content of the water above 5mg / L;

[0089] (4.3) Control the light in the culture environment, that is:

[0090] The light intensity is below 1000Lx, the light is uniform, and the light cycle is light: dark = 12h:12h;

[0091] (4.4) Control the culture environment, namely:

[0092] The aquaculture water temperature is 17-25℃, the salinity is 25-32‰, the pH is 7.8-8.3, and the water is slightly aerated. The dissolved oxygen is above 5mg / L. The water quality is monitored daily and the pond is emptied once a month. Before the pond is emptied, astaxanthin is used for 5 consecutive days at a dosage of 10mL / kg mixed with feed. Before and after the pond is emptied, astaxanthin feeding is stopped and VC Yingjiling is sprayed at a dosage of 0.5g / m 3 ;

[0093] When the water temperature is higher than 25℃, the feed should be halved. The remaining bait and feces should be siphoned out 2 hours after each feeding. The light, water temperature, salinity and other environmental factors should be kept stable to prevent the occurrence of stress response, and the diseased and dead individuals in the breeding pond should be cleaned up in time.

[0094] Denoted as S1.

[0095] Example 2

[0096] The difference from Example 1 is that:

[0097] (4.1) Adjust the stocking density in time according to the size of the seedlings. The stocking density is:

[0098] ≤1cm seedlings 2000 / m 3 ;

[0099] 1500 seedlings / m 3 ;

[0100] 1000 fry / m3 of 3-5cm 3 ;

[0101] 5~8cm seedlings 600 / m 3 ;

[0102] 400 scorpionfish larger than 8cm / m 3 ;

[0103] During the cultivation period, individuals with uneven size and growth are screened and cultured in separate ponds to ensure that the specifications of seedlings in the same breeding pond are uniform.

[0104] Denoted as S2.

[0105] Example 3

[0106] The difference from Example 1 is that:

[0107] (4.1) Adjust the stocking density in time according to the size of the seedlings. The stocking density is:

[0108] ≤1cm seedlings: 1500 / m 3 ;

[0109] 1000 seedlings / m 3 ;

[0110] 800 fry / m3 of 3-5cm 3 ;

[0111] 5-8cm seedlings 500 / m 3 ;

[0112] 300 scorpionfish larger than 8cm / m 3 ;

[0113] During the cultivation period, individuals with uneven size and growth are screened and cultured in separate ponds to ensure that the specifications of seedlings in the same breeding pond are uniform.

[0114] Denoted as S3.

[0115] Comparative Example 1

[0116] Step 1: The farm is located in a sea area with smooth and pollution-free sea flow and convenient transportation. The water used for aquaculture is sand-filtered natural seawater;

[0117] Step 2: Select artificially bred parents of Xu's flatfish, and select female fish with uniform size, normal body color, no body damage, no disease or deformity. Place the mated female fish ready to give birth in a 15℃ naturally filtered seawater breeding pond for breeding. After the fry are produced, they are promptly removed and placed in the fry breeding pond;

[0118] Step 3: Adjust the stocking density according to the size of the seedlings. The stocking density is:

[0119] ≤1cm seedlings 2500 / m 3 ;

[0120] 2000 seedlings / m 3 ;

[0121] 1500 fry / m3 of 3-5cm 3 ;

[0122] 5~8cm seedlings 700 / m 3 ;

[0123] 500 scorpionfish larger than 8cm / m 3 During the cultivation period, individuals with uneven growth and size are selected and cultivated in separate ponds to ensure uniform specifications of seedlings in the same breeding pond;

[0124] The breeding environment uses natural light, and the light cycle is a natural day and night cycle.

[0125] The aquaculture water temperature is 15-25℃, the salinity is 25-32‰, the pH is 7.8-8.3, and there is a slight amount of aeration. The dissolved oxygen is above 5mg / L. The water quality is monitored daily and the pond is emptied once a month.

[0126] Newly hatched larvae were fed rotifers from day 1 to 15, and the water was replaced by 50% of fresh seawater daily;

[0127] From day 15 to day 30, feed rotifers and Artemia nauplii, and replace 50% of the water with fresh seawater daily;

[0128] From the 30th to the 45th day, feed Artemia nauplii and compound feed, and change the water volume by 50% to 100% every day;

[0129] After the 45th day, feed compound feed and fresh seawater are often used for breeding; the above baits are rinsed clean and free of pathogens;

[0130] When the seedlings are ≤2cm in length, feed them in small amounts and multiple times, 4-5 times a day. When the seedlings are >2cm in length, they are obviously phototropic, so feed them intensively, 2-3 times a day.

[0131] Rotifers are fed at 5 / mL of the culture water, and Artemia nauplii are fed at 3-5 / mL. Before feeding, nutritional fortification is required. The rotifer fortifier is fortified yeast. The culture density of rotifers is 500 / ml, the amount of fortifier is 0.25g / L (water volume), and the fortification is for 12 hours. The water temperature is about 28°C, the salinity is 28-30, the pH is 8.0-8.4, the light intensity is about 1000Lx, and it is adequately aerated.

[0132] The enhancer of Artemia nauplii is Schizochytrium powder, the culture density is 150 / ml, the amount of enhancer is 0.4g / L (water volume), the enhancer is 12h, the water temperature is about 28℃, the salinity is 28-30, the pH is 8.0-8.4, the light intensity is about 1000Lx, and the water is aerated sufficiently;

[0133] When the water temperature is higher than 25℃, the feed should be halved. The remaining bait and feces should be siphoned out 2 hours after each feeding. The light, water temperature, salinity and other environmental factors should be kept stable to prevent the occurrence of stress response, and the diseased and dead individuals in the breeding pond should be cleaned up in time.

[0134] Denoted as D1.

[0135] Comparative Example 2

[0136] The difference from Comparative Example 1 is that:

[0137] Step 3: Adjust the stocking density according to the size of the seedlings. The stocking density is:

[0138] ≤1cm seedlings 2000 / m 3 ;

[0139] 1500 seedlings / m 3 ;

[0140] 1000 fry / m3 of 3-5cm 3 ;

[0141] 5~8cm seedlings 600 / m 3 ;

[0142] 400 scorpionfish larger than 8cm / m 3 During the cultivation period, individuals with uneven size and growth are screened and cultured in separate ponds to ensure that the specifications of seedlings in the same breeding pond are uniform.

[0143] Denoted as D2.

[0144] Comparative Example 3

[0145] The difference from Comparative Example 1 is that:

[0146] Step 3: Adjust the stocking density according to the size of the seedlings. The stocking density is:

[0147] ≤1cm seedlings: 1500 / m 3 ;

[0148] 1000 seedlings / m 3 ;

[0149] 800 fry / m3 of 3-5cm 3 ;

[0150] 5-8cm seedlings 500 / m 3 ;

[0151] 300 scorpionfish larger than 8cm / m 3 During the cultivation period, individuals with uneven size and growth are screened and cultured in separate ponds to ensure that the specifications of seedlings in the same breeding pond are uniform.

[0152] Denoted as D3.

[0153] Experimental example

[0154] After 90 days of culturing the fry of S. philippinarum using the culturing methods provided in the above Examples 1 to 3 and Comparative Examples 1 to 3, the survival rates of S. philippinarum individuals in different groups were statistically analyzed. The results are shown in Table 1.

[0155] Table 1 Survival rate and body length of individuals in different groups of Scorpionfish

[0156]

[0157] The above Table 1 shows that the breeding method provided by the present invention can significantly improve the survival rate and growth rate of the seedlings.

[0158] In summary, the breeding method provided by the present invention selects lively and healthy individuals artificially cultivated in cages at sea by the original breeding farm of Xu's flatfish as stable parents for breeding seedlings, improves the breeding efficiency of Xu's flatfish parents and the environmental adaptability of seedlings through nutritional fortification, controls reasonable breeding density according to different specifications of breeding seedlings, and optimizes the use of microecological preparations and feed additives, etc., reduces the water pollution and disease incidence rate of the breeding environment, and the disease incidence rate of Xu's flatfish is generally less than 5%, thereby improving the survival rate, and controlling the flow rate of the seedling breeding water body, enhancing the natural behavior ability of the seedlings and improving the growth performance of the seedlings, and the growth rate is increased by more than 5%, which has good application prospects. It can be seen from the embodiment that the above-mentioned breeding method can significantly improve the survival rate and growth rate of the individuals in the breeding period of the seedlings by breeding Xu's flatfish for 90 days.

[0159] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will comply with the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A method for improving the quality of fry of Scorpionfish, characterized in that: The following steps are involved: Step 1: Select a farm and adjust the quality of water used for breeding; Step 2: Select the parent species of Xu's flathead scorpionfish; Select active and healthy 2-year-old mature parents that were artificially bred and cultured in cages at sea at Xu's flatfish stock farm in advance; Step 3: Breeding of the parent stock of Xu's flathead scorpionfish; The parents after the breeding treatment in step 2 are placed in a culture pond in a ratio of female to male = 1:1, and after the parents mate, the fertilized female fish are taken out and placed in a breeding pond to wait for birth, and after birth, the newly hatched seedlings are placed in a seedling cultivation pond for cultivation; Step 4: Seedling breeding (4.1) Control the stocking density, that is: When the seedlings are fry with a length of ≤1cm, the stocking density is 2000-2500 / m 3 ; When the fry are fry with a length of >1cm and ≤3cm, the stocking density is 1500-2000 / m 3 ; When the fry are fry with a length of >3cm and ≤5cm, the stocking density is 1000-1500 / m 3 ; When the fry are fry with a length of >5cm and ≤8cm, the stocking density is 700-800 / m 3 ; When the length of the seedlings is greater than 8 cm, the stocking density is 500-600 / m 3 . (4.2) Feeding of seedlings, namely: Feed the seedlings with rotifers on the 1st to 15th day after birth, and sprinkle fresh Chlorella until the water body has a slight algae color; Feed the seedlings with rotifers and Artemia nauplii on the 15th to 30th day after birth, and sprinkle fresh Chlorella until the water body has a slight algae color; Feed the seedlings with Artemia nauplii and a 0.25-0.36mm particle size mixed feed for sea urchin fry on the 30th to 45th day after birth, and sprinkle or mix with microecological preparations, feed additives and disease control drugs; When the seedlings are ≥45 days old, they are fed with a feed with appropriate particle size according to the seedling size, and microecological preparations, feed additives and disease prevention drugs are sprinkled or mixed into the feed; (4.3) Control the light in the culture environment, that is: The intensity of the illumination is below 1000 Lx, and the illumination cycle is light:dark=12h:12h; (4.4) Control the breeding environment, namely: The water temperature for aquaculture is 17℃~25℃, of which the water temperature in spring is ≥17℃ and the water temperature in summer is ≤25℃; The salinity of the water used in the farm is 25‰~32‰, the pH is 7.8~8.3, and the dissolved oxygen content is ≥5mg / L. The pond is emptied once a month. Before emptying the pond, astaxanthin is used for 5 consecutive days at a dosage of 10mL / kg mixed with feed. Before and after emptying the pond, astaxanthin feeding is stopped and VC Yingjiling is sprayed at a dosage of 0.5g / m 3 .

2. A method for cultivating fish for improving the quality of fry of Scorpionfish according to claim 1, characterized in that: The aquaculture farm described in step 1 is selected around a sea area with smooth and pollution-free sea flow and convenient transportation; the water quality of aquaculture water meets the requirements of pollution-free food seawater aquaculture water quality NY5052-2001.

3. A method for cultivating fish for improving the quality of fry of Scorpionfish according to claim 1, characterized in that: The parent stock in step 2 has a size of ≥2kg, the temperature of the parent breeding sea area is 13°C, and the parent stock is fed with fresh frozen small fish and small shrimp during the breeding period, and the parent stock is fed until full, and the remaining bait is cleaned up in time the next day.

4. A method for cultivating fish for improving the quality of fry of Scorpionfish according to claim 1, characterized in that: The density of fertilized female fish in the breeding pond in step 3 is 1 fish / m 3 , the output process is: Select female fish that are about to give birth, wrap the fish body with a cloth soaked in seawater and cover the eyes of the female fish, gently squeeze the fish abdomen towards the reproductive opening, and the mature fry will slowly flow into the pre-prepared water tank. Stop squeezing the fry after the outflow speed of the fry slows down, put the parent fish back into the pond and mark the net cage, and squeeze the fry again after 2 to 4 hours until the birth is completed; The culture pool contains naturally filtered seawater at a temperature of 13°C. The temperature is raised by 0.5°C every day during the culture period and is temporarily maintained at a constant temperature when the temperature reaches 17°C.

5. The method for raising the quality of fry of Scorpionfish according to claim 1, characterized in that: In step (4.2), the feeding amount of rotifers is 6 to 8 per mL, and the feeding amount of Artemia nauplii is 3 to 5 per mL according to the volume of the culture water body; The microecological preparation, feed additive, disease prevention and control medicine and use method are: Brown sugar-free EM probiotics once a week, 3-5g / m 3 ; 0.2% multivitamin, once a week, diluted 2g / kg feed each time; bile acid is used at a dosage of 4-6g / kg feed each time, once a week for prevention, and used for 5 consecutive days for treatment; poplar flower essence, 10mL / kg each time, mixed with enteritis killer 5g / kg feed, once a week for prevention, and used for 3-5 consecutive days for treatment; When the seedlings are ≤2cm in length, feed them 4-5 times a day; when the seedlings are >2cm in length, feed them 2-3 times a day.

6. A method for cultivating fish for improving the quality of fry of Scorpionfish according to claim 1, characterized in that: The daily fresh seawater replacement rate is 50% from the 1st to the 15th day after the seedlings are born; the daily fresh seawater replacement rate is 50% to 100% from the 15th to the 45th day after the seedlings are born; and fresh seawater is used for constant flow culture after the 46th day after the seedlings are born.

7. A method for cultivating fish for improving the quality of fry of Scorpionfish according to claim 6, characterized in that: In fresh seawater constant flow aquaculture, the flow rate is controlled at 1BL / s.

8. The method for raising the quality of fry of Scorpionfish according to claim 1, characterized in that: The rotifers and Artemia nauplii described in step (4.2) need to be subjected to nutritional enrichment treatment before being fed.

9. A method for cultivating fish for improving the quality of fry of Scorpionfish according to claim 8, characterized in that: The culturing method of the rotifer comprises the following steps: The culture density is 500 cells / mL, the water temperature is 28℃, the salinity is 28-30, the pH is 8.0-8.4, the light intensity is 1000Lx, and sufficient aeration is used to maintain the dissolved oxygen content of the water above 5mg / L; The enhancer for the rotifer nutritional enhancement treatment is Schizochytrium powder, the dosage is 0.25 g / L based on the volume of the water body, and the nutritional enhancement time is 12 hours; The method for cultivating Artemia nauplii comprises the following steps: The culture density was 150 cells / mL, the water temperature was 28°C, the salinity was 28-30, the pH was 8.0-8.4, the light intensity was 1000Lx, and there was sufficient aeration; The enhancer for the Artemia salina nutritional enhancement treatment includes Schizochytrium powder, the amount of the enhancer is 0.4 g / L based on the volume of the water body, and the nutritional enhancement time is 12 hours.

10. A method for cultivating fish for improving the quality of fry of Scorpionfish according to claim 1, characterized in that: When the seedlings are fed with rotifers and Artemia nauplii 15 to 30 days after birth in step (4.2), the feeding method of the rotifers and Artemia nauplii is: feeding the rotifers normally, reducing the amount of rotifers fed in the afternoon, supplementing with a small amount of Artemia nauplii, and gradually advancing the feeding time of Artemia nauplii and increasing the feeding amount of Artemia nauplii in the later stage until the feeding of rotifers is stopped; Specifically: from 15 to 20 days, the amount of rotifers fed in the afternoon is reduced by 1 / ml, and the amount of Artemia fed is increased by 1 / ml; from 20 to 25 days, the amount of rotifers fed in the afternoon is reduced by 2 / ml, and the amount of Artemia fed is increased by 2 / ml; from 25 to 30 days, the amount of rotifers fed is 0, and the amount of Artemia fed is 5 / ml; When the seedlings are fed with Artemia nauplii and compound feeds at 30 to 45 days after birth, the feeding method of Artemia nauplii and compound feeds is: feeding Artemia nauplii normally, reducing the feeding amount of Artemia nauplii in the afternoon, supplementing with a small amount of compound feeds, and gradually advancing the feeding time of compound feeds and increasing the feeding amount of compound feeds in the later stage until the feeding of Artemia nauplii is stopped, specifically: On the 30th to 35th day, the Artemia feeding amount is reduced by 1 / ml in the afternoon. On the 35th to 40th day, the Artemia feeding amount is reduced by 2 / ml in the afternoon. On the 40th to 45th day, the Artemia feeding amount is 0. Feed the compound feed in small amounts and multiple times according to the degree of fullness.

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