CN105875453A - Crossbreeding method for improving high-temperature tolerance of patinopecten yesoensis - Google Patents

Abstract

The invention discloses a crossbreeding method capable of improving the high temperature tolerance of Ezo scallop. The female oyster of Ezo scallop and the long ribbed clam are used as brood shells, and fertilization is carried out at a water temperature of 18-19°C, and sperm and egg cells are fertilized. High fertilization rate, rapid development of embryos and larvae, significantly shortened development time to D-shaped larvae and juvenile shellfish, can provide hybrid shellfish seedlings with fast growth and strong stress resistance, and finally obtained scallops and offspring hybrid scallops adapt to The ability of high temperature environment has been enhanced, and there is still no death phenomenon when the seawater reaches 26°C, which can expand the cultivation range of Ezo scallop.

Description

Cross-breeding method for improving high temperature tolerance of Ezo scallop

technical field

The invention relates to the field of marine shellfish genetics and breeding, in particular to a hybrid breeding method for improving high temperature tolerance of Ezo scallop.

Background technique

Pationopecten yessoensis is large and grows fast, and it is the main economic shellfish cultured in the northern coast of China. In the 1980s, it was successfully introduced into China from Japan and realized artificial propagation technology. However, since the Ezo scallop is native to Hokkaido, Japan, its living water temperature does not exceed 23°C. If the water temperature in artificial culture reaches 23°C, it will die on a large scale, causing huge economic losses to the farmers. Because of this, shrimp Yi scallops are currently only cultured in coastal areas such as Changhai, Dalian, Liaoning.

Amusium pleuronectes belongs to Bivalvia, Pterioida, Pectinidae and Amusium . The long-ribbed Riyue mussel is large, fast-growing, rich in nutrition, and delicious in meat. Its dried product is a rare sea treasure "scallop". The hermaphrodite is a warm-water species. As a traditional economic shellfish in my country, it is mainly distributed in coastal areas such as Hainan and Guangdong.

Scallop scallops and clams long ribs belong to different genera and species in classification, and the long-term geographical isolation makes the two have significant differences in biology. So far, there is no related report on the distant hybrid breeding of Ezo scallop and long ribbed clam.

Contents of the invention

The present invention is to solve the above-mentioned deficiencies existing in the prior art, and proposes a hybrid breeding method for improving the high temperature tolerance of Ezo scallop,

The technical solution of the present invention is: a kind of crossbreeding method that improves Ezo scallop high temperature tolerance, it is characterized in that carry out according to the following steps:

a. Select the long-ribbed sun moon clam and Ezo scallop female as hybrid broodstock;

b. Artificial breeding to make the gonads of the hybrid brood mature at the same time;

c. Ovulation of the female scallop scallop and sperm of the long ribbed shellfish were obtained by induced labor;

d. Mating eggs and sperm to produce fertilized eggs and hatching fertilized eggs into D-shaped larvae;

e. Grow D-shaped larvae to spat.

When the seawater in the sea area where the scallop grows rises to 24~25°C, select the 2-year-old and above as the hybrid brood; The female shellfish of Ezo scallop is a hybrid broodstock.

After the hybrid broodstock were washed and disinfected, they were put into different cultivation ponds for cultivation, and the cultivation density was 10-15/m ³ water body, and the mixed algae of Chrysophylla and Nitzschia crescentus and yeast powder were fed once in the morning and evening. Sargassum powder fermentation broth, the daily feeding amount of the mixed algae is 100,000 to 150,000/ml water body, and the addition amount of the fermentation broth is 5 to 8 ppm/ ^m3 water body; the cultivation water temperature of long rib sun and moon broodstock Start from 24-25°C, lower the temperature by 0.5°C every day until it drops to 18±0.5°C, and cultivate it at a constant temperature until the gonads mature. ±0.5 ℃, constant temperature culture until gonad mature.

The gonad-matured hybrid broodstock was dried in the shade at room temperature for 2 hours, and then the hybrid broodstock was stimulated with running water for 0.5-1 hour. The female scalloped shellfish was placed in 12°C seawater irradiated with ultraviolet rays, and the long ribbed clamshell Put them into 20°C seawater irradiated with ultraviolet rays, and collect the eggs laid by the Ezo scallop and the sperm excreted by the long rib clam.

The collection of the sperm discharged from the long ribbed shellfish is to immerse the semened long ribbed shellfish in a seawater container with ultraviolet light at 20°C when the long ribbed shellfish is ejaculating. Shellfish continued to ejaculate for 5 to 10 minutes to collect sperm.

For example, adding sodium hydroxide solution to seawater at 20°C irradiated with ultraviolet rays of the long ribbed shellfish to raise the pH of the seawater to 9.0 ~ 9.2 can accelerate the ejaculation of the long ribbed shellfish.

The collection of the sperm discharged from the long ribbed shellfish is to obtain the male gonads of the long ribbed shellfish by dissecting, and the obtained gonads are filtered through a 600 mesh screen into a 0.2‰ ammonia seawater beaker, and the final concentration is added to the beaker. 0.2 ~ 0.5 ppm calf serum was activated, and the sperm was collected after 20 ~ 30 min of activation.

The step d is as follows: slowly increase the temperature of seawater in the collected eggs to 18-19°C, slowly reduce the temperature of the seawater in the collected sperm to 18-19°C, and press 10 to ~ 15:1 ratio for mixed fertilization. Before fertilization, adjust the salinity of seawater at 18 ~ 19°C to 33.5 ~ 34.0. During the fertilization process, a low-power wave pump is used to stir the water body, so that the sperm and egg cells are evenly distributed and finally form fertilized eggs. The fertilized eggs are hatched to D-shaped larvae in the hatching tank. During the hatching period, the water is slightly aerated and the water is stirred once an hour.

The e step is as follows: the D-shaped larvae are selected with a 400-mesh sieve, moved to aerated culture in the cultivation pond, the cultivation density of the D-shaped larvae in the cultivation pond is 12 ~ 15 ind/ml, and the seawater in the cultivation pond is all passed through Three-stage sand filter, the cultivation water temperature is 18-19°C, the pH is 8.02-8.15, and the salinity is 32.3-33.1. The water in the cultivation pond is changed every morning and evening, and the daily water change is 80-150%. The D-shaped larva opens the bait For Chrysophytes, the daily feeding amount is 15,000 to 20,000/ml water body. When the average shell length of the D-shaped larvae is 120 µm, start feeding Chrysophytes and Nitzschia, and the daily feeding amount of Chrysophytes is 2.0 ~ 25,000 pcs/ml of water body, and 15,000 to 20,000 pcs/ml of water body per day, and when the average shell length of the D-shaped larvae is 160 μm, add flat algae on the basis of the above-mentioned bait. The daily feeding amount of algae is 0.5 to 10,000/ml of water until it grows to juvenile shellfish.

In the present invention, the female scallop shellfish and the long ribbed shellfish are used as broodstock, and fertilized under the condition of water temperature of 18-19°C, the fertilization rate of sperm and egg cells is high, the embryo and larvae develop quickly, and D-shaped larvae and larvae are developed. The time of juvenile scallops is significantly shortened, and hybrid scallops with fast growth and strong stress resistance can be provided. The ability of the finally obtained scallops and their progeny hybrid scallops to adapt to high temperature environments has been enhanced, and there is no death in seawater up to 26°C Phenomenon, can expand the scope of cultivation of Ezo scallop.

detailed description

The present invention improves the crossbreeding method of Ezo scallop high temperature tolerance, carries out according to the following steps:

a. Select the long-ribbed sun moon clam and Ezo scallop female as hybrid broodstock:

In mid-March, when the seawater in the sea area where the scallop grows rises to 24-25°C, select the sea shell that is more than 2 years old as the hybrid brood; when the seawater where the scallop grows rises to 2-3°C, Female scallop shellfish over 2 years old were selected as hybrid broodstock.

b. Artificial breeding to mature the gonads of hybrid broodstock at the same time:

After the hybrid broodstock were washed and disinfected, they were put into different cultivation ponds for cultivation, and the cultivation density was 10-15/m ³ water body, and the mixed algae of Chrysophylla and Nitzschia crescentus and yeast powder were fed once in the morning and evening. Sargassum powder fermentation liquid, the daily feeding amount of the mixed algae is 100,000 to 150,000/ml water body, and the addition amount of the fermentation liquid is 5 to 8 ppm/ ^m3 water body; Start from 24-25°C, lower the temperature by 0.5°C every day until it drops to 18±0.5°C, and cultivate it at a constant temperature until the gonads mature. ±0.5 ℃, constant temperature culture until gonad mature. In this way, the simultaneous maturation of the gonads of the long-rib sun and moon broodstock and the Ezo scallop can be guaranteed.

c. Obtain eggs of female scallop scallop and sperm of long ribbed shellfish by induced labor:

The gonad-matured hybrid broodstock was dried in the shade at room temperature for 2 hours, and then the hybrid broodstock was stimulated with running water for 0.5-1 hour. The female scalloped shellfish was placed in 12°C seawater irradiated with ultraviolet rays, and the long ribbed clamshell Put them into seawater at 20°C irradiated with ultraviolet rays, collect the eggs produced by the Ezo scallop and the sperm discharged by the long rib clam respectively, that is, when the long rib sun moon molluscs are found to ejaculate, immediately remove the ejaculated long rib sun moon Immerse the shellfish in a seawater container with ultraviolet light at 20°C, and the long-ribbed sun and moon shellfish can continue to ejaculate for 5 to 10 minutes to collect sperm.

If the long-ribbed sun and moon shellfish excrete slowly, you can add sodium hydroxide solution to the 20°C seawater soaked in the ultraviolet rays of the long-ribbed sun and moon shellfish to raise the pH of the seawater to 9.0 ~ 9.2 to speed up the long-ribbed sun and moon shellfish. Ejaculate.

It is also possible to obtain the male gonads of the long ribbed shellfish by dissection, filter the obtained gonads through a 600-mesh screen into a 0.2‰ ammonia seawater beaker, and add calf serum with a final concentration of 0.2 to 0.5 ppm into the beaker for activation. Sperm were collected after 20-30 min.

d. Mating eggs and sperm to produce fertilized eggs and hatching fertilized eggs into D-shaped larvae:

Slowly increase the seawater temperature in the collected eggs to 18 ~ 19°C, slowly reduce the seawater temperature in the collected sperm to 18 ~ 19°C, and mix the sperm of the long ribbed shellfish and the egg cells of the Ezo scallop at a ratio of 10 ~ 15:1 Mixed fertilization. Before fertilization, adjust the salinity of seawater at 18-19°C to 33.5-34.0. During the fertilization process, use a low-power wave pump to stir the water body, so that the sperm and egg cells are evenly distributed and finally form fertilized eggs. Fertilized eggs are placed in the hatching tank Hatched to D-shaped larvae, slightly aerated during hatching, stirring the water once an hour.

e. Rearing D-shaped larvae to spat:

The D-shaped larvae are selected with a 400-mesh sieve, and moved to the cultivation pond for aerated culture. The D-shaped larvae in the cultivation pond are cultivated at a density of 12 to 15 ind/ml. The water temperature is 18-19°C, the pH is 8.02-8.15, and the salinity is 32.3-33.1. The water in the cultivation pond is changed every morning and evening, and the daily water change is 80-150%. The feeding amount is 15,000 to 20,000/ml water body. When the average shell length of D-shaped larvae is 120 µm, start feeding Chrysophylla and Nitzschia crescentus. The daily feeding amount of golden algae is 20,000 to 25,000/ml water body , and the daily feeding amount of Nitzschia is 15,000 to 20,000/ml water body; when the average shell length of D-shaped larvae is 160 μm, the flat algae is supplemented on the basis of the above-mentioned bait, and the daily feeding amount of flat algae is 0.5 ~ 10,000/ml water body, until the spat grow to adulthood. However, the optimum temperature for growth and development of common Ezo scallop larvae was 15.0-17.5 ℃, and the survival rate decreased significantly when the water temperature reached 19.0 ℃.

The juvenile scallops were bred according to conventional methods to obtain progeny hybrid scallops with excellent traits such as fast growth, large size, and high temperature resistance. When the seawater reaches 26°C, there is still no death phenomenon, and the obtained adult scallops are close to the scallops in appearance and properties, and can be expanded to coastal waters such as Shandong for cultivation, expanding the range of scallops for cultivation.

Claims (9)

1. a method for cross-breeding improving high temperature tolerance of scallops, characterized in that it is carried out in the following steps: a. Select the long-ribbed sun moon clam and Ezo scallop female as hybrid broodstock; b. Artificial breeding to make the gonads of the hybrid brood mature at the same time; c. Ovulation of the female scallop scallop and sperm of the long ribbed shellfish were obtained by induced labor; d. Mating eggs and sperm to produce fertilized eggs and hatching fertilized eggs into D-shaped larvae; e. Grow D-shaped larvae to spat. 2. The hybrid breeding method for improving the high temperature tolerance of Ezo scallop according to claim 1, characterized in that the step a is as follows: when the seawater in the sea area where the long-ribbed scallop grows rises to 24 ~ 25 ° C, select 2 years old or more The long-ribbed scallops are hybrid broodstock; when the seawater where the scallop grows rises to 2-3°C, female scallops over 2 years old are selected as the hybrid broodstock. 3. the hybrid breeding method for improving the high temperature tolerance of Ezo scallop according to claim 1, characterized in that the b step is as follows: after the hybrid parent shellfish is cleaned and sterilized, it is put into different cultivation ponds for cultivation respectively, and the cultivation The density is 10 to 15 per ^m3 water body, and the mixed algae of Chrysophylla and Nitzschia Crescent and the fermented liquid of yeast powder and sargassum powder are fed once in the morning and evening, and the daily feeding amount of the mixed algae is 100,000 to 150,000 pcs/ml water body, the added amount of the fermentation broth is 5-8 ppm/m ³ water body; the cultivation water temperature of long-ribbed sun and moon broodstock starts from 24-25°C, and the temperature is lowered by 0.5°C every day until it drops to 18±0.5°C. Cultivate at a constant temperature until the gonads are mature. The water temperature of the broodstock of Ezo scallops starts from 2 to 3°C, and the temperature is raised by 0.5°C every day until the temperature rises to 7±0.5°C, and the water is cultivated at a constant temperature until the gonads mature. 4. The hybrid breeding method for improving the high temperature tolerance of scallop according to claim 3, characterized in that the c step is as follows: dry the hybrid parent shellfish with mature gonads in the shade for 2 h at room temperature, and then stimulate the scallop with running water. After hybridizing broodstock for 0.5-1 h, put the female scalloped shellfish in 12°C seawater irradiated with ultraviolet rays, put the long rib clam in 20°C seawater irradiated with ultraviolet light, and collect the eggs and Sperm discharged from the long ribbed shellfish. 5. The method of cross-breeding for improving the high temperature tolerance of Ezo scallop according to claim 4, characterized in that: said collecting the sperm of the long-ribbed sun and moon shellfish is when the long-ribbed sun and moon shellfish ejaculate, and the ejaculate Immerse the refined long-rib gillfish in a seawater container at 20°C irradiated with ultraviolet rays, and continue to ejaculate for 5 to 10 minutes to collect sperm. 6. The cross-breeding method for improving the high temperature tolerance of Ezo scallop according to claim 4, characterized in that: add sodium hydroxide solution to the 20°C seawater irradiated with ultraviolet rays of the long ribbed shellfish to raise the pH of the seawater As high as 9.0 ~ 9.2. 7. the method for cross-breeding of improving the high temperature tolerance of Ezo scallop according to claim 4, characterized in that: the collection of the sperm of the long ribbed shellfish is to obtain the male gonad of the long ribbed shellfish by anatomical method, and the The obtained gonads were filtered through a 600-mesh sieve into a 0.2‰ ammonia seawater beaker, and calf serum with a final concentration of 0.2-0.5 ppm was added to the beaker for activation, and sperm were collected after activation for 20-30 min. 8. The hybrid breeding method for improving high temperature tolerance of Ezo scallop according to claims 4, 5, 6, and 7, characterized in that the step d is as follows: the temperature of seawater in the collected eggs is slowly raised to 18-19°C , slowly reduce the temperature of the seawater in the collected sperm to 18-19°C, mix the sperm of the long ribbed shellfish and the egg cells of the scallop scallop at a ratio of 10-15:1 for fertilization, and adjust the salinity of the seawater at 18-19°C before fertilization. to 33.5 ~ 34.0. During the fertilization process, a low-power wave-making pump is used to stir the water body, so that the sperm and egg cells are evenly distributed and finally form fertilized eggs. The fertilized eggs are hatched in the hatching tank to D-shaped larvae. water once. 9. The method for cross-breeding that improves the high temperature tolerance of Ezo scallop according to claim 8, characterized in that the e step is as follows: the D-shaped larva is selected with 400 mesh screens, and moved to the cultivation pond for aeration Cultivation, the cultivation density of D-shaped larvae in the cultivation pool is 12 ~ 15 ind/ml, the sea water in the cultivation pond is filtered through three-stage sand, the temperature of the cultivation water is 18 ~ 19°C, and the pH is 8.02 ~ 8.15, the salinity is 32.3 ~ 33.1, the water in the cultivation pond is changed every morning and evening, and the amount of water changed every day is 80 ~ 150%. Water body, when the average shell length of D-shaped larvae is 120 µm, start to feed Chrysophytes and Nitzches. The daily feeding amount of Chrysophytes is 20,000 to 25,000/ml water body, and the daily feeding amount of Nitzches is 1.5 ~ 20,000/ml water body; the average shell length of D-shaped larvae is 160 µm, add flat algae on the basis of the above-mentioned bait, and the daily feeding amount of flat algae is 0.5 to 10,000/ml water body until it grows to juvenile shellfish.