Construction and breeding method of fast-growing family of oplegnathus punctatus

Abstract

The invention provides a construction and breeding method of a fast-growing family of oplegnathus punctatus, and belongs to the technical field of artificial breeding. The invention provides an oplegnathus punctatus family construction method. The oplegnathus punctatus family construction method comprises the following steps: carrying out artificial spawning induction on female and male parents of oplegnathus punctatus in a breeding season, respectively collecting unfertilized eggs and semen by adopting an abdomen extrusion method, mixing the unfertilized eggs and the semen, activating by utilizing seawater to complete artificial dry fertilization, and taking the fertilized eggs as a group of families. According to the method, the full length and the body weight of the obtained oplegnathus punctatus family are measured at different stages, and high-quality varieties which grow quickly can be screened out.

Description

Technical Field

[0001] The invention belongs to the technical field of artificial breeding, and particularly relates to a construction and breeding method of a fast-growing family of rockfish. Background Art

[0002] Oplegnathus punctatus, commonly known as spotted bream and black gold drum, belongs to the order Perciformes, family Oplegnathidae, and genus Oplegnathus. It is mainly distributed in the middle and lower layers of warm and tropical coastal waters, often active in reefs and corals. It is colorful and is commonly known as "coral reef fish". Due to its unique taste, delicate meat, and edible and medicinal value, it has been loved by consumers in recent years, but due to the scarcity of natural resources, the wild catch is relatively small. In 2014, Laizhou Mingbo Aquatic Products Co., Ltd. made a breakthrough in the artificial breeding technology of spotted bream for the first time. The stable and high-quality seed output made spotted bream a new type of aquaculture variety, and also laid the foundation for the subsequent large-scale breeding and excellent variety cultivation of spotted bream. However, the lack of fast-growing germplasm of spotted bream has limited the development of the spotted bream industry. Therefore, the selection and breeding of excellent varieties of spotted bream and the creation of excellent germplasm are important links to promote the further development of the spotted bream industry.

[0003] Growth traits have always been one of the hot issues in the field of aquatic research. Selective breeding is a traditional breeding method that uses the original population for purposeful and planned repeated selection and elimination to isolate stable genetically excellent varieties. Family selection is the most widely used breeding technology in selective breeding. It is to establish a family and compare and observe each family as a unit to enrich the dominant genes and improve the homozygosity of target shape-related genes. Family selection technology has been applied in many fish and has achieved fruitful results. Yang Huizan et al. established an XX-type all-female GIFT tilapia family to provide high-quality female parents for the large-scale seed production of all-male GIFT tilapia, and then provide basic materials for tilapia sex control and breeding research; Lian Zitong et al. used family selection technology to screen out 4 fast-growing families of yellow eel (Monopterus albus); Wei Xinjian et al. compared the growth performance of 32 constructed large yellow croaker (Pseudosciaena crocea) families and screened out 3 fast-growing families. However, there is a problem of difficulty in constructing a pedigree for the spotted sea bream. Summary of the invention

[0004] The invention provides a method for constructing and breeding a fast-growing family of spotted rockfish, which can quickly construct a spotted rockfish family and can be applied to the cultivation and screening of new varieties of spotted rockfish.

[0005] The present invention provides a method for constructing a pedigree of a spotted rock porgy, comprising the following steps: artificially inducing spawning of female and male parents of the spotted rock porgy during the breeding season, collecting unfertilized eggs and semen respectively by squeezing the abdomen, mixing the unfertilized eggs and semen, activating them with seawater to complete artificial dry fertilization, and using the fertilized eggs as a group of families.

[0006] In a preferred embodiment of the present invention, the sources of the female and male parents of the spotted sea bream include wild spotted sea bream parents from Japan, and the sex of the wild spotted sea bream parents is identified.

[0007] In a preferred embodiment of the present invention, the parents whose sexes have been identified are electronically marked and then temporarily cultured in a pond.

[0008] In a preferred embodiment of the present invention, the breeding season includes March to April of the Gregorian calendar every year.

[0009] In a preferred embodiment of the present invention, during the breeding season, 4-5 years old, healthy, 2000-2500 g in weight and 40-50 cm in length of female and male spotted porgy are selected to construct spotted porgy families.

[0010] In a preferred embodiment of the present invention, when performing the artificial dry insemination, the volume ratio of semen to unfertilized egg is 500 μL: (50-150) mL.

[0011] In a preferred embodiment of the present invention, the amount of seawater used is twice the volume of the unfertilized eggs.

[0012] In a preferred embodiment of the present invention, the fertilized eggs after artificial dry fertilization are evenly distributed in a mesh screen for incubation.

[0013] In a preferred embodiment of the present invention, after the artificial dry fertilization is performed for 24 hours, the sunken unfertilized dead eggs are picked out, and then each group of families is incubated separately.

[0014] In a preferred embodiment of the present invention, the water temperature during incubation is 25±0.5°C.

[0015] The present invention also provides application of the construction method in cultivating new germplasm of rock bream.

[0016] Beneficial effects: The present invention provides a method for constructing a family of spotted porgy, comprising the following steps: artificially inducing spawning of female and male spotted porgy parents during the breeding season, collecting unfertilized eggs and semen respectively by squeezing the abdomen, mixing the unfertilized eggs and semen, activating them with seawater to complete artificial dry fertilization, and using the fertilized eggs as a group of families. The present invention uses wild spotted porgy parents from Japan provided by Laizhou Mingbo Aquatic Products Co., Ltd., and uses the construction method to establish a total of 40 spotted porgy families. The total length and weight are measured at different stages, and it is found that there are large differences in the growth of spotted porgy between different families and within different families. The weight of fast-growing families No. 7, No. 14 and No. 34 is nearly twice that of slow-growing families. The family breeding technology method can be used to screen out fast-growing and excellent varieties. In addition, in order to further study the daily and stage weight gain of each family, the present invention also analyzes the daily weight gain rate and the relative weight gain rate, and finds that in the early stage of fry (before 90 days), families 12, 16, 23, 27, 29, 33 and 36 grow faster than families 7 and 14; but at 90 to 180 days of age, families 7, 14 and 34 grow faster than other families; as of 180 days of age, families 7, 14 and 34 still grow significantly faster than other families, so families 7, 14 and 34 are identified as fast-growing families. DETAILED DESCRIPTION

[0017] The present invention provides a method for constructing a pedigree of a spotted rock porgy, comprising the following steps: artificially inducing spawning of female and male parents of the spotted rock porgy during the breeding season, collecting unfertilized eggs and semen respectively by squeezing the abdomen, mixing the unfertilized eggs and semen, activating them with seawater to complete artificial dry fertilization, and using the fertilized eggs as a group of families.

[0018] The parent of the spotted rock bream described in the present invention can be a wild-type spotted rock bream. For example, in the embodiment, a wild spotted rock bream from Japan is selected as a parent, which is provided by Laizhou Mingbo Aquatic Products Co., Ltd. The present invention selects male and female individuals with good growth and development, good health, and good gonadal development as reserve parents. Before pedigree construction, the sex of the spotted rock bream needs to be identified. The sex identification includes using the spotted rock bream sex-specific DNA molecular markers to identify the sex of the spotted rock bream reserve parent fish. The molecular markers have been disclosed in literature materials (Li Ming. Preliminary study on the genomics of spotted rock bream and the establishment of sex-specific marker discovery and genetic sex identification technology. Shanghai Ocean University doctoral dissertation. 2020).

[0019] The present invention electronically marks the parents after sex identification and temporarily raises them in a pond, and selects female and male parents of spotted porgy to construct spotted porgy families in the breeding season, wherein the breeding season includes March to April of the Gregorian calendar each year. In the breeding season, the present invention selects female and male parents of spotted porgy that are 4 to 5 years old, healthy, weigh 2000 to 2500 g and are 40 to 50 cm long to construct spotted porgy families.

[0020] The present invention artificially induces labor on male and female parents, collects unfertilized eggs by squeezing the abdomen, and collects the unfertilized eggs into a dry beaker for later use; similarly, the abdominal squeezing method is used to collect the semen of male spotted porgy, and the eggs of each female fish are artificially dry fertilized with the sperm of one male fish. The minimum volume ratio of semen and unfertilized eggs for fertilization in the present invention is 500 μL: (50-150) mL, and seawater with a volume of 2 times the amount of eggs is added to activate and complete fertilization as a family, and the floating fertilized eggs are evenly distributed in a mesh screen for incubation; after 24 hours, the unfertilized dead eggs that sink are picked out, and then each family group is incubated separately, and the water temperature is maintained at 25±0.5°C.

[0021] The present invention also provides application of the construction method in cultivating new germplasm of rock bream.

[0022] After obtaining different families, the present invention further comprises testing the growth performance of the different families, wherein the growth performance comprises weight and total length, wherein the measurement standards of weight comprise daily weight gain rate and relative weight gain rate, and the measurement standards of total length comprise daily growth rate and relative growth rate.

[0023] in,

[0024] Daily weight gain (DWG) = W / T;

[0025] Daily growth rate (DWL) = L / T;

[0026] Relative weight gain rate (RWGR) = (W2-W 1) / (T2-T 1);

[0027] Relative growth rate (RLGR) = (L2-L 1) / (T2-T 1);

[0028] T represents the number of days after the fry hatched (d), W is the average body weight corresponding to T (g), and L is the average total length corresponding to T (cm); T1 and T2 are the actual growth days of the fry at the two measurements (d), W1 and W2 are the average body weight of the fry at T1 and T2, respectively, and L1 and L2 are the average body length of the fry at T1 and T2, respectively.

[0029] In order to further illustrate the present invention, the construction and breeding method of a fast-growing family of spotted sea bream provided by the present invention are described in detail below in combination with the embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0030] Example 1

[0031] 1. Materials and Methods

[0032] 1.1 Parental Materials

[0033] The wild rockfish parents from Japan in the present invention are provided by Laizhou Mingbo Aquatic Products Co., Ltd., and male and female individuals with good growth and development, good health and good gonadal development are selected as reserve parents. The sex of the reserve parent fish of the rockfish of the company is identified by using the sex-specific DNA molecular marker of the rockfish. The identified parents are electronically marked and temporarily raised in the pond. In the breeding season (March to April), the female and male rockfish parents of 4 to 5 years old, healthy, weighing 2000 to 2500g and 40 to 50cm in length are selected to construct the rockfish family.

[0034] 1.2 Family construction

[0035] Artificial induction of labor was performed on both male and female parents, and unfertilized eggs were collected by squeezing the abdomen. The unfertilized eggs were collected in a dry beaker for later use. The semen of male spotted porgy was also collected by squeezing the abdomen. The eggs of each female fish were artificially dry fertilized with the sperm of one male fish. The minimum volume ratio of semen to eggs for fertilization was 500μL: (50-150)mL. Seawater with a volume of 2 times the amount of eggs was added to activate the fertilization and treat it as a family. The floating fertilized eggs were evenly distributed on the mesh for incubation. After 24 hours, the unfertilized dead eggs that sank were picked out, and then each family was incubated separately, and the water temperature was maintained at 25±0.5℃.

[0036] 1.3 Measurement and data analysis

[0037] When the spotted sea bream families grew to 90 and 180 days of age, about 30 individuals were randomly selected from each family for weight and full length measurement. The data obtained were analyzed using SPSS19 statistical software, and the weight and full length mean values ​​and annotation errors of each period were calculated. Multiple comparisons were used to analyze the growth differences between each family. When P<0.05, the differences were significant and represented by different letters.

[0038] 2. Results and Analysis

[0039] 2.1 Statistical analysis of the total length and weight of the family of rock snapper

[0040] In April 2023, 40 families of spotted rock bream were successfully established through artificial induction of labor and artificial insemination. At 180 days of age, about 30 fish were randomly selected from each family for growth performance measurement, totaling 1,193 fish. The data showed that at 180 days of age, the body length of spotted rock bream ranged from 11.20 to 20.20 cm, with an average body length of 15.30 cm (Table 1); the body weight ranged from 33.80 to 270.60 g, with an average body weight of 92.46 g (Table 1).

[0041] Table 1 Statistical results of body length and weight of 180-day-old spotted sea bream

[0042]

[0043] 2.2 Analysis of growth performance of different families

[0044] In order to analyze the growth performance of the spotted rock bream families, the body length and weight data of the spotted rock bream families were measured at 90 and 180 days after hatching. The results showed that the body length and weight of the families were quite different. The average total length at 90 days old was 5.48-7.44 cm, and the average weight was between 5.14 and 12.42 g; the average total length at 180 days old was 14.25-17.72 cm, and the average weight was between 70.04 and 164.37 g. According to the analysis of the 180-day-old data, the average weight of families 7, 14 and 34 was higher among the 40 families, all above 140 g; the average weight of families 3, 4, 6, 9, 17, 22, 28, 29 and 36 was lower among the 40 families, all below 80 g (Table 2). Based on the growth performance at 180 days of age, families 7, 14 and 34 were preliminarily defined as fast-growing families, and families 3, 4, 6, 9, 17, 22, 28, 29 and 36 were preliminarily defined as slow-growing families.

[0045] Table 2 Average total length and average body weight of each family of rockfish at different growth stages

[0046]

[0047]

[0048] Analysis of the daily growth rate and daily weight gain rate as well as the relative growth rate and relative weight gain rate of each family at 180 days of age showed that the daily growth rate of 40 families was between 0.0791 and 0.0985 cm / day, and the daily weight gain rate was between 0.3891 and 0.9131 g / day; the daily growth rate and daily weight gain rate of fast-growing families 7, 14 and 34 were higher among all families, ranging from 0.0954 to 0.0985 cm / day and 0.7805 to 0.9131 g / day, respectively (Table 3). To further determine the growth performance of each family, the relative growth rate and relative weight gain rate at different stages were analyzed. The results showed that the relative growth rate within 90 days of age was between 0.0609 and 0.0826, and the relative weight gain rate was between 0.0571 and 0.138; the relative growth rate from 90 to 180 days of age was between 0.0838 and 0.1251, and the relative weight gain rate was between 0.6843 and 1.7231 (Table 3); the relative weight gain rate and growth rate of the fast-growing families 7, 14 and 34 were higher than those of the other families at all stages.

[0049] Table 3 Analysis of DWG, DWL, RWGR and RLGR of each family of 180-day-old rockfish

[0050]

[0051]

[0052] In summary, the present invention has established 40 families of spotted rock bream, and measured the total length and weight at different stages. It is found that there are large differences in the growth of spotted rock bream between different families and within different families. The weight of fast-growing families No. 7, No. 14 and No. 34 is nearly twice that of slow-growing families. The family selection technology method can screen out fast-growing excellent varieties. In addition, the daily weight gain rate and relative weight gain rate are analyzed, and it is found that in the early stage of fry (before 90 days), families No. 12, No. 16, No. 23, No. 27, No. 29, No. 33 and No. 6 grow faster than families No. 7 and No. 14; but at 90 to 180 days of age, families No. 7, No. 14 and No. 34 grow faster than other families; by 180 days of age, families No. 7, No. 14 and No. 34 still grow significantly faster than other families, so families No. 7, No. 14 and No. 34 are identified as fast-growing families, which can be applied to the subsequent breeding of fast-growing new varieties.

[0053] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for constructing a pedigree of a grouper, characterized in that: The following steps are involved: During the breeding season, artificial spawning is performed on female and male parents of grouper sea bream. Unfertilized eggs and semen are collected separately by squeezing the abdomen. The unfertilized eggs and semen are mixed and activated with seawater to complete artificial dry fertilization. The fertilized eggs are regarded as a family group.

2. The construction method according to claim 1, characterized in that: The sources of the female and male parents of the spotted seabream include wild spotted seabream parents from Japan, and the sex of the wild spotted seabream parents is identified.

3. The construction method according to claim 2, characterized in that: The method comprises electronically marking the parents identified by sex and then temporarily raising them in a pond.

4. The construction method according to claim 1, characterized in that: The breeding season includes March to April of the Gregorian calendar every year.

5. The construction method according to claim 1 or 4, characterized in that: During the breeding season, 4-5 years old, healthy female and male parents of the spotted seabream, weighing 2000-2500g and 40-50cm in length, were selected to construct the spotted seabream family.

6. The construction method according to claim 1, characterized in that: When performing the artificial dry insemination, the volume ratio of semen to unfertilized eggs is 500 μL: (50-150) mL.

7. The construction method according to claim 6, characterized in that: The amount of seawater used is twice the volume of the unfertilized eggs.

8. The construction method according to claim 1, characterized in that: The fertilized eggs after artificial dry fertilization are evenly distributed on the mesh screen for incubation.

9. The construction method according to claim 8, characterized in that: The water temperature during the incubation was 25±0.5°C.

10. Use of the construction method according to any one of claims 1 to 9 in cultivating new germplasm of Gnaphalium striata.

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