CN104542408B - Method for synchronous line establishment of small-population parents in artificial breeding of exopalaemon carinicauda - Google Patents

Abstract

The invention discloses a method for artificially selecting and synchronizing the parents of a small group of white shrimps to establish a line. In the non-breeding peak period when the water temperature is relatively low, the temperature control method is used in the three developmental stages (the developmental stage of the brood shrimp gonad, the fertilized egg embryo) development stage and larval development stage) to regulate the water temperature, so that the family lines built by the small group parents in different gonad development stages can be concentrated as much as possible during the development to the larval stage, and finally realize the synchronous establishment of the small group parents. The present invention sets temperature gradients for the suitable temperature ranges of different developmental stages of the white shrimp, which is beneficial to shorten the development time difference of the offspring of each parent, and realizes the synchronous establishment of a small and medium-sized group of parents of the white shrimp artificially breeding and multiple generations in a year breeding.

Description

A method for synchronous line establishment of small populations of artificially selected white shrimp

technical field

The invention relates to the technical field of aquaculture, in particular to a method for synchronously establishing lines of small populations of white shrimp artificially selected and bred.

Background technique

The white prawn is a bottom-dwelling shrimp in the temperate tropical sea area, with the highest yield in the Yellow Sea and the Bohai Sea. It is one of the three unique economic shrimps in China, and its output is second only to the Chinese prawn and the Chinese hairy shrimp. White prawns have strong environmental adaptability, fast growth, good meat quality, high economic value, and considerable economic benefits from farming. It is a potential shrimp species for breeding. At present, its farming output has reached one-third of the total output of polyculture ponds in the eastern coastal areas of my country. one or so. White prawns are resistant to low temperature and suitable for a wide range of salt, and can be cultured in freshwater ponds after desalination. It has a wide range of culture and great potential. However, most of the current seed sources are natural offspring of wild populations or cultured populations, and there are no artificially selected fine strains to choose from, and fine aquaculture species are very important for the economic benefits of aquaculture units. Artificial breeding is a breeding method that artificially obtains new varieties that meet the breeding goals through trait selection, purification, and comparative identification. It is the most effective way to improve the germplasm of aquaculture animals at this stage.

The generation cycle of most aquaculture species is calculated in units of years, while the traditional family establishment cycle is usually about 20-30 days, and the line establishment cycle accounts for a relatively small proportion of the generation cycle (less than 8%). It has little impact on the comparison and selection of traits between families, but the generation cycle of the white shrimp is short, only 3-4 months, and the traditional method of establishing a line is too long (accounting for more than 20%), which is not conducive to the comparison of traits among families and select. However, previous studies mainly focused on the methods of establishment of shrimp families and breeding strategies, and there is no report on how to shorten the breeding cycle. At the same time, in order to speed up the breeding process, it is feasible and necessary to use the short generation cycle of the white shrimp to achieve multi-generational reproduction in a controlled environment, but in the non-breeding season when the water temperature is low, the gonad development of the parents The synchronization is poor, and the department establishment cycle will be longer. Therefore, shortening the breeding cycle as much as possible to facilitate the comparison and selection of traits among families has become an urgent task in the artificial breeding of white prawns.

Contents of the invention

The invention discloses a method for synchronously establishing a line of parents of a small population of white shrimp artificially selected. The method can greatly shorten the line establishment period of the small population of white shrimp, and shorten the traditional line establishment period from 20-30 days to 3 days. -In about 5 days, the synchronous establishment of the line was basically realized, which provided technical support for the comparison of traits among the lines and the accuracy of selection.

In order to achieve the above object, the technical solution provided by the present invention is a method for synchronously establishing a line of small population parents of white shrimp artificially selected, and the specific steps of the method are as follows:

(1) Selection of parents, early cultivation and grouping: During the non-breeding peak period when the water temperature is low, select male and female parents that have reached sexual maturity and have no injuries in appearance, gradually raise the water temperature to about 25°C and maintain it, and feed them. The fresh bait is nutrient-enriched, and when more than half of the female shrimps are found to have ovarian tissue in the cephalothorax, these female shrimps are picked out separately and divided into early gonad development, middle gonad development, and late gonad development according to the degree of ovarian development. Grouping, while the male shrimps are not grouped, and continue to be cultivated at 25°C;

(2) Synchronization of gonad development: adjust the breeding water temperature of the above three groups of female shrimp to 27°C, 25°C and 23°C respectively, continue to feed fresh bait, observe the gonad development every day, when the ovary develops to close to When laying eggs, the single-tailed female shrimp is transferred to the mating and spawning box respectively, and 1 tail of sexually mature male shrimp is put into it. After the female shrimp has eggs, it is transferred to the same water temperature as the water temperature for cultivating egg-bearing shrimps.

(3) Synchronization of embryonic development: maintain the cultivation temperature of the above three groups of ovum-bearing shrimp at 27°C, 25°C and 23°C respectively. When the larvae are about to hatch, transfer the ovum-bearing shrimp to the hatching tank. Using phototaxis to collect larvae as a family;

(4) Synchronization of larvae development: Adjust the larvae cultivation temperature of the above three groups to 29, 27 and 25°C respectively and maintain them. Artemia nauplii are fed throughout the larvae cultivation process, and the water is changed appropriately depending on the water quality. After all the larvae metamorphose For post-larvae enumeration, candidate lines for the larval rearing stage were selected.

Wherein, the number of the male and female parent individuals is less than 500.

Among them, the male to female ratio of the parents is 1:1.

Among them, the selection criteria for the parents are: reach sexual maturity (body length greater than 4cm, weight greater than 1g), appearance without injury (transparent body color, microstrip blue or red spots; smooth appearance, no attachments; head and chest No damage to nails, appendages, abdominal segments, and tail fans, no broken forehead sword, no other trauma or deformity; no brown spots, black gills, red bodies, soft shells, white spots, etc.), good vitality (response to external stimuli) Sensitive, strong bouncing, normal swimming posture, no side lying, etc.).

Among them, the nutrition strengthening measure is to supply fresh and live bait of lugworm, squid and fresh clam meat, and the ratio of artificially formulated bait to fresh and live bait is preferably 1:3.

Among them, the criteria for judging that the ovaries are developed to be close to spawning are that the ovaries are clear and the ovaries are full of the middle and back of the carapace.

Among them, the volume of the mating and spawning box should not be too large, preferably about 50L.

Wherein, the judging standard and collection method that the larvae are about to hatch in the step (3) is to transfer the ovum-bearing shrimp to the hatching tank when the embryo appearance of the ovum-bearing shrimp is translucent off-white and the eyespots are clear, and observe the gonads every day. Development status, when the ovary is close to spawning, transfer the egg-bearing shrimp to the 50L mating spawning box, use the hatching net to limit the activity range of the broodstock, after the larvae hatch, use the phototaxis of the larvae to separate the broodstock from the larvae; etc. After the larvae hatched completely, remove the broodstock in time, collect the larvae with good phototaxis and strong vitality, count them and transfer them to the larvae cultivation tank as a candidate family of a larvae stage.

Wherein, the step (4) selects the candidate families in the larval cultivation stage, and selects according to the time from metamorphosis to larvae, the number of larvae and the survival rate of metamorphosis.

Wherein, the selection method of the candidate families in the larva cultivation stage in the step (4) is as follows: the time for complete metamorphosis into larvae is concentrated within 5 days, the number of larvae is greater than 500, and 100 of the top 100 in metamorphosis survival rate family lineage.

The advantages of the present invention are:

1. The temperature control measures are simple and easy to implement, which is convenient for popularization and application;

2. The temperature control gradient is designed according to the optimal temperature range of each developmental stage, which has no obvious impact on the growth and development of the offspring of the family;

3. Synchronized line establishment is beneficial to reduce the influence of breeding age and environmental differences on the growth, immunity and other traits of the families, thereby improving the accuracy of trait selection;

4. This method can be popularized and applied to the artificial breeding of other aquaculture species with a short period of time.

In the non-breeding peak period, the present invention uses a temperature control method to regulate water temperature in three developmental stages (gonad developmental stage of broodstock, fertilized egg embryonic developmental stage and larval developmental stage), so that the small group parents in different gonadal developmental stages can build The time of family development to the stage of larvae should be concentrated as much as possible, and finally realize the synchronous establishment of small population parents. The present invention is very necessary and critical for realizing multi-generation selection and breeding of white prawns in one year, shortening the line establishment period as much as possible, and realizing the synchronous establishment of lines in the non-breeding peak period of small population parents.

detailed description

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope of the present invention.

Embodiment 1, a method for synchronously establishing a line of parents of small populations of white shrimp artificially selected

This embodiment proceeds according to the following steps:

(1) Parent selection: the parent of the white shrimp is taken from the 3rd generation reserved seed family of artificial breeding, and the breeding age is about 120 days. One week before the experiment, they had been labeled with different staining combinations. On October 20, 2014, 1000 broodstock shrimps with smooth and complete body surface, no injury, body length greater than 4cm, and average weight of about 1.5g were selected and put into 2 indoor cement ponds (volume 5m ³ , density 150/ m ² or so) for 7 days. Keep the natural temperature during the temporary breeding period, and feed artificial compound bait ("Hengxing" brand prawn compound feed, protein content 40%, 5% total weight of experimental shrimp) every day, remove dead shrimp in time and change the water appropriately according to the water quality;

Early cultivation: After the broodstock enters the pond for 7 days, use a temperature controller (equipped with a 2KW heating rod) to slowly raise the temperature by 1°C every morning and afternoon (2°C/day). After 5 days of warming up to 25°C, the water temperature was maintained no longer, and the clam worm and artificial bait (mass ratio 3:1) were fed once a day, and adjusted (increased or decreased) according to the feeding situation. ) feeding amount; during this period, another cement pool without shrimps was heated up synchronously as a water exchange for experimental broodstock.

Grouping: When half of the female shrimps are found to have ovarian tissue in the cephalothorax by visual observation, these female shrimps are picked out. According to the difference in gonad development (mainly ovary volume), the female broodstock were divided into three groups: early gonad development (D1), middle gonad development (D2) and late gonad development (D3), and 100 shrimps were taken from each group , and continued to culture under different temperature gradients.

(2) Synchronization of gonad development

A total of 3 temperature gradients (27, 25, 23°C) were set up, in which the cultivation water temperature of the D1 group was increased to 27°C, the cultivation water temperature of the D2 group was maintained at 25°C, and the water temperature of the D3 group was dropped to 23°C. Observe the development of the gonads every day. When the ovary develops close to spawning, transfer the single-tailed female shrimp to the 50L mating and spawning box, and put one sexually mature male shrimp into it. Cultivate ovum-bearing shrimp in the same water temperature tank, and record the date of ovulation.

(3) Synchronization of embryonic development

A total of 3 temperature gradients (27, 25, 23°C) were set up, and the hatching temperatures of the brood shrimp obtained in groups D1, D2, and D3 were maintained at 27, 25, and 23°C, respectively. When the appearance of the embryos is translucent off-white, transfer the egg-bearing shrimps to the hatching tank, observe the gonad development every day, and when the ovaries are close to laying eggs, transfer the female shrimps to a 50L plastic incubator, and use a hatching net (15cm × 15cm × 15cm) to limit the activity range of broodstock. After the larvae hatch, the broodstock is separated from the larvae by using the phototaxis of the larvae. After the larvae hatch completely, remove the broodstock in time, collect larvae with good phototaxis and strong vitality, count 800 and transfer them to the larvae cultivation tank (50L) as a family, and record the hatching date.

(4) Synchronization of larval development

A total of 3 temperature gradients (29, 27, 25°C) were set up, and the larvae cultivation temperatures in groups D1, D2, and D3 were adjusted to 29, 27, and 25°C, respectively, and maintained. Artemia nauplii were fed throughout the larvae cultivation, and the water was changed appropriately depending on the water quality. When more than 90% of the larvae metamorphose into larvae, it is considered that the larvae stage is over, count and record the date, select the family with a number of larvae greater than 500 as the candidate family, and start family cultivation after standardization (quantity standardization, 500/family) ; The selection method of the candidate families in the larva cultivation stage is as follows: the time of complete metamorphosis to larvae is concentrated within 5 days, the number of larvae is greater than 500, and the survival rate of metamorphosis ranks top 100 in 100 families.

Synchronization effect: After about 4 weeks of synchronous regulation, 300 female shrimp whose gonad development span reached more than 10 days established a total of 186 families that met the requirements, of which 137 families (73.7%) were concentrated in the 28- After 31 days, 100 families were selected according to the ranking of the number of larvae and the metamorphosis survival rate as the candidate families of the larvae stage.

Through the three-stage synchronization measures, the line establishment cycle that originally lasted more than ten days can be compressed to 3-5 days, thus realizing the synchronous generation generation of family selection and breeding.

The technology and method of the present invention can also be used in artificial breeding research of other short-generation cycle aquatic animals.

In the non-breeding peak period, the present invention uses a temperature control method to regulate water temperature in three developmental stages (gonad developmental stage of broodstock, fertilized egg embryonic developmental stage and larval developmental stage), so that the small group parents in different gonadal developmental stages can build The time of family development to the stage of larvae should be concentrated as much as possible, and finally realize the synchronous establishment of small groups of parents. The present invention sets temperature gradients for the suitable temperature ranges of different developmental stages of the white shrimp, which is beneficial to shorten the development time difference of the offspring of each parent, and realizes the synchronous establishment of a small and medium-sized group of parents of the white shrimp artificially breeding and multiple generations in a year breeding.

The foregoing is a description of the embodiments of the present invention, and through the above descriptions of the disclosed embodiments, those skilled in the art can implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. a method for synchronously establishing lines of small group parents of white shrimp artificially selected, is characterized in that, the specific steps of the method are as follows: (1) Selection of parents, early cultivation and grouping: During the non-breeding peak period when the water temperature is low, select male and female parents that have reached sexual maturity and have no injuries in appearance, gradually raise the water temperature to about 25°C and maintain it, and feed them. The fresh bait is nutrient-enriched, and when more than half of the female shrimps are found to have ovarian tissue in the cephalothorax, these female shrimps are picked out separately and divided into early gonad development, middle gonad development, and late gonad development according to the degree of ovarian development. Grouping, while the male shrimps are not grouped, and continue to be cultivated at 25°C; (2) Synchronization of gonad development: adjust the breeding water temperature of the above three groups of female shrimp to 27°C, 25°C and 23°C respectively, continue to feed fresh bait, observe the gonad development every day, when the ovary develops to close to When laying eggs, the single-tailed female shrimp is transferred to the mating and spawning box, and 1 tail of sexually mature male shrimp is put into it. After the female shrimp has ovum, it is transferred to the ovum-bearing shrimp cultivation tank whose water temperature is the same as the cultivation water temperature to continue to cultivate; (3) Synchronization of embryonic development: maintain the cultivation temperature of the above three groups of brood shrimp at 27°C, 25°C and 23°C respectively. Phototaxis collected larvae as a candidate family for 1 larval stage; (4) Synchronization of larval development: adjust the larval cultivation temperature of the above three groups to 29°C, 27°C and 25°C respectively and maintain them, feed Artemia nauplii throughout the larval cultivation, and change the water appropriately depending on the water quality. After the larvae are all metamorphosed into larvae, they are counted, and the candidate families in the larvae cultivation stage are selected. 2. The method for synchronously establishing a line of small-group parents of white shrimp artificially selected according to claim 1, wherein the number of male and female parents is less than 500. 3. the artificial breeding method of small group of white shrimp artificial breeding as claimed in claim 1, is characterized in that, the selection standard of described step (1) parent is: reach sexual maturity specification, outward appearance has no injury or disease, Vitality is good, the ratio of male to female is 1:1. 4. The method for synchronous establishment of a small group of parents of white shrimp artificially selected according to claim 3, wherein the sexually mature standard is that the body length is greater than 4cm and the body weight is greater than 1g; the appearance is free from injuries and diseases Refers to transparent body color, microstrip blue or red spots; smooth appearance, no attachments; no trauma and deformity; no brown spots, black gills, red bodies, soft shells, and white spots; The stimulus response is sensitive, the bounce is strong, the swimming posture is normal, and there is no side lying. 5. The method for artificially selecting small populations of white prawns for artificial breeding as claimed in claim 1, wherein the method for synchronously establishing a line of parents is characterized in that, in the step (1), nutritional enhancement is to supply the fresh and alive meat of clams, squids and fresh clams. For bait, the ratio of artificial bait to fresh bait is preferably 1:3. 6. The method for artificially breeding small populations of white prawns as claimed in claim 1, wherein the method for synchronously establishing a line of parents in a small population is characterized in that, in the step (2), the criterion for judging that the ovary develops to be close to spawning is that the ovary is clear, the ovary Fills the middle and back of the carapace. 7. The method for synchronously establishing lines of small group parents of white prawns artificially selected according to claim 1, wherein the volume of the spawning box for mating in the step (2) is 50L. 8. The method for synchronously establishing a line of small group parents of white prawns artificially selected according to claim 1, characterized in that the judging standard and collection method for the larvae to be hatched in the step (3) are when ovum-bearing shrimps are observed When the appearance of the embryo is translucent off-white and the eyespots are clear, transfer the egg-bearing shrimp to the hatching tank and observe the gonad development every day. The hatching net limits the activity range of the broodstock. After the larvae hatch, use the phototaxis of the larvae to separate the broodstock from the larvae; remove the broodstock in time after the larvae hatch completely, collect the larvae with good phototaxis and strong vitality, and transfer them to the larvae after counting. Sink as a candidate lineage at the 1 larval stage. 9. The artificial breeding method for the small-group parental synchronous line-building of white shrimp as claimed in claim 1, characterized in that, the step (4) selects the candidate family of the larvae cultivation stage, based on the metamorphosis to the larvae. Time, the number of larvae and the survival rate of metamorphosis were used for selection. 10. the artificial selection method of small population parent of white prawn as claimed in claim 9, is characterized in that, the selection method of the candidate family line in the larval shrimp cultivation stage in the described step (4) is: complete metamorphosis is The time of larvae is concentrated within 5 days, the number of larvae is more than 500, and the survival rate of metamorphosis ranks in the top 100 100 families.