A method for inducing synchronous maturation of shrimp broodstock

Abstract

The application provides a method for promoting synchronous maturation of parent shrimps, which comprises the following steps: temporarily breeding male parent shrimps and female parent shrimps in a pool; adjusting water flow velocity to perform water flow domestication and temperature domestication, setting the water flow velocity to be 0.4-1.5 m / s, and feeding nutrition enhancer to perform intensive feeding when the water flow domestication is performed; the nutrition enhancer comprises the following components: taurine, arachidonic acid, phosphatidylserine and cuttlefish bone powder; setting the temperature to be 18-19 DEG C, increasing the temperature by 0.4-0.6 DEG C per day, and increasing the temperature to 27-28 DEG C. The water flow domestication and the temperature domestication are performed by adjusting the water flow velocity, and the intensive feeding of the nutrition enhancer is combined when the water flow domestication is performed, which is beneficial to the accumulation of nutritional substances in the hepatopancreas tissue of the female shrimps, promotes synchronous development and maturation of the ovary, and can make the maturation rate of the female shrimps reach 100%, and the synchronous maturation rate reach 80%.

Description

TECHNICAL FIELD

[0001] The present application relates to the shrimp breeding technical field, and particularly relates to a method for promoting synchronous sexual maturation of parent shrimps. BACKGROUND

[0002] Macrobrachium rosenbergii, also known as Malaysian prawn or freshwater long-clawed shrimp, has become a large country for Macrobrachium rosenbergii breeding in China due to its fast growth speed, wide food habit and other advantages. With the expansion of the Macrobrachium rosenbergii breeding scale, in the condition of large-scale breeding, synchronous breeding of uniform size seedlings in the same period is required. Different ovary development leads to long breeding time of seedlings, and is prone to intra-group killing and other phenomena, reduces the breeding performance of seedlings, and is prone to congenital deficiency in later development. Therefore, how to promote the synchronous development of gonads of Macrobrachium rosenbergii is one of the current research hotspots. At present, more researches are on the development rule of ovary and testis of Macrobrachium rosenbergii, and the synchronous ovary development of Macrobrachium rosenbergii still needs to be researched. SUMMARY

[0003] In view of this, the purpose of the present application is to provide a method for promoting synchronous sexual maturation of parent shrimps, which can help to provide a good acclimation environment for synchronous ovary development of Macrobrachium rosenbergii, avoid gonadal development delay or excessive development, and reduce the adverse reactions such as stress reaction and peroxidation reaction of parent shrimps, so as to effectively improve the reproductive performance of parent shrimps.

[0004] The technical scheme of the present application is implemented as follows:

[0005] A method for promoting synchronous sexual maturation of parent shrimps, comprising the following steps:

[0006] S1 temporary breeding: temporarily breeding male parent shrimps and female parent shrimps in a pool;

[0007] S2 acclimation and strengthening: adjusting water flow speed to perform water flow acclimation and temperature acclimation, setting the water flow speed to 0.4-1.5 m / s, and feeding a nutrition enhancer to perform intensive feeding when performing water flow acclimation;

[0008] The components of the nutrition enhancer include taurine, arachidonic acid, phosphatidylserine and cuttlefish powder;

[0009] The temperature is set to 18-19 DEG C, and the temperature is increased by 0.4-0.6 DEG C per day until the temperature reaches 27-28 DEG C.

[0010] Further, the water flow acclimation is performed for 20-80 min per day.

[0011] Further, the water flow acclimation is performed 2-4 times per day, and each time is 10-20 min.

[0012] Further, the water flow domestication is performed for 12-16 days.

[0013] Further, the water flow domestication comprises high-speed water flow domestication for 6-8 days and low-speed water flow domestication for 6-8 days, the water flow speed of the high-speed water flow domestication is 1.2-1.5 m / s, and the water flow speed of the low-speed water flow domestication is 0.4-0.6 m / s.

[0014] Further, the temperature rising comprises three gradually transitioned temperature rising stages: the first stage is rising to 21-22 DEG C, the second stage is rising to 24-25 DEG C, and the third stage is rising to 27-28 DEG C.

[0015] Further, the first stage is: when rising to 21-22 DEG C, stopping rising, and maintaining the water temperature of 21-22 DEG C for 3-4 days.

[0016] The second stage is: when rising to 24-25 DEG C, stopping rising, and maintaining the water temperature of 24-25 DEG C for 3-4 days.

[0017] The third stage is: rising to 27-28 DEG C until the target parent prawns are harvested.

[0018] Further, the nutritional enhancer comprises the following components in parts by weight: 24-32 parts of taurine, 12-22 parts of arachidonic acid, 8-16 parts of phosphatidylserine and 50-58 parts of cuttlefish bone powder.

[0019] Further, the feeding amount of the nutritional enhancer is 0.8-1.2% of the weight of the parent prawns.

[0020] Further, the parent prawns are Macrobrachium rosenbergii.

[0021] Compared with the prior art, the method has the following beneficial effects:

[0022] The method of the present application is beneficial to the accumulation of nutrients in the hepatopancreas of female prawns, promotes the synchronous development and maturation of ovaries, and can make the maturation rate of female prawns reach 100% and the synchronous maturation rate reach 80%.

[0023] The water flow domestication and temperature domestication obtained by the present application can provide a good domestication environment for the synchronous development of ovaries of Macrobrachium rosenbergii, avoid slow or rapid development of gonads, and combine with the nutritional enhancer to promote the development of gonads of parent prawns, reduce adverse reactions such as stress reaction and peroxidation reaction, and achieve the purpose of effectively improving the reproductive performance of parent prawns.

[0024] The method of the present application can improve the reproductive capacity of parent prawns, enhance the immunity of parent prawns, lay a material foundation for the growth of fry in the later stage, and ensure the nutrition, survival rate, size, etc. of fry. Detailed Implementation

[0025] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0026] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0027] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0028] Example 1

[0029] Select healthy, lively adult giant freshwater prawns with no surface injuries, weighing approximately 2.2–2.5 g. Temporarily raise them in a pond at a female-to-male ratio of 1:1 for 5 days, with a stocking density of 15 prawns / m². 2 The shrimp were fed formulated feed at 6% of their body weight, twice a day, in the morning and afternoon. Uneaten feed and feces were promptly removed. Water salinity was controlled at 24–26, pH at 7.8–8.1, and dissolved oxygen at greater than 7 mg / L. Five experimental groups were established for broodstock rearing. The control group was fed only formulated feed for giant freshwater prawns (Yangzhou Hongda Feed Co., Ltd., adult shrimp feed), with water salinity controlled at 24–26, pH at 7.8–8.1, temperature at 27–28℃, and dissolved oxygen at greater than 7 mg / L. No water flow or temperature acclimatization or nutritional fortification was performed.

[0030] Experimental Group 1: Water flow acclimatization and temperature acclimatization were carried out by adjusting the water flow speed. First, the water flow speed of high speed acclimatization (1.2-1.5 m / s) was used for 7 days, and then the water flow speed of low speed acclimatization (0.4-0.6 m / s) was used for 7 days. Water flow acclimatization was carried out 4 times a day for 15 minutes each time.

[0031] Meanwhile, during the water flow acclimatization process, a nutrient fortifier was added for enhanced feeding, with the amount of nutrient fortifier being 1% of the weight of the broodstock shrimp.

[0032] The nutritional fortifier is a mixture of 28 parts taurine, 17 parts arachidonic acid, 12 parts phosphatidylserine, and 52 parts cuttlebone powder.

[0033] The initial temperature is set at 18℃, and the temperature is increased by 0.5℃ per day. When the temperature reaches 22℃, the temperature increase is stopped and maintained at 22℃ for 3 days. Then, the temperature is increased by 0.5℃ per day until it reaches 25℃. When the temperature is stopped, the temperature is maintained at 25℃ for 4 days. Finally, the temperature is increased by 0.5℃ per day until it reaches 28℃, until the target broodstock shrimp are harvested.

[0034] Experimental group 2: adjusting water flow velocity to conduct water flow and temperature domestication, setting water flow velocity 0.4-0.6 m / s, conducting water flow domestication for 14 days, conducting water flow domestication 4 times per day, each time for 15 min;

[0035] Meanwhile, when conducting water flow domestication, feeding nutrition enhancer to conduct intensive feeding, the feeding amount of nutrition enhancer is 1% of the weight of parent shrimps;

[0036] The nutrition enhancer is composed of 28 parts of taurine, 17 parts of arachidonic acid, 12 parts of phosphatidylserine and 52 parts of cuttlefish powder;

[0037] Setting initial temperature as 18℃, increasing water temperature by 0.5℃ per day, increasing water temperature to 28℃, until harvesting target parent shrimps.

[0038] Experimental group 3: adjusting water flow velocity to conduct water flow and temperature domestication, setting water flow velocity 0.4-0.6 m / s, conducting water flow domestication for 14 days;

[0039] Feeding nutrition enhancer and compound feed at the same time, once in the morning and once in the afternoon, the feeding amount of nutrition enhancer is 1% of the weight of parent shrimps;

[0040] The nutrition enhancer is composed of 28 parts of taurine, 17 parts of arachidonic acid, 12 parts of phosphatidylserine and 52 parts of cuttlefish powder;

[0041] Setting initial temperature as 18℃, increasing water temperature by 0.5℃ per day, increasing water temperature to 22℃, stopping increasing water temperature, maintaining 22℃ water temperature for 3 days, then increasing water temperature by 0.5℃ per day, increasing water temperature to 25℃, stopping increasing water temperature, maintaining 25℃ water temperature for 4 days, finally increasing water temperature by 0.5℃ per day, increasing water temperature to 28℃, until harvesting target parent shrimps.

[0042] The experiment was conducted for 20 days, after which the feeding was stopped for 24 hours, 10 female shrimps were randomly selected, the ovary volume, size and color characteristics were observed, the ovary tissue was taken out, the gonadosomatic index was calculated, the gonadosomatic index GSI = ovary fresh weight / body weight x 100%, according to the following ovary development period, the female shrimps were classified, the maturation rate was calculated, the maturation rate = the number of female shrimps developed to phase VI at the same time / total number, the synchronous maturation rate = the number of female shrimps in phase VII at the same time / total number.

[0043] Phase I: the ovary is small and not easy to observe;

[0044] Phase II: the ovary can be observed with the naked eye, the volume is 2-3 times larger than that in phase I;

[0045] Phase III: the ovary is obvious and very easy to observe, the whole is milky white;

[0046] Stage IV: The ovary volume is increased, and the whole ovary is milky white, not transparent, and a small amount of yellowish white;

[0047] Stage V: The ovary is obvious, and a large amount of yellowish white is present;

[0048] Stage VI: The ovary is obvious, and presents dark green, not transparent, and ovules are present;

[0049] Stage VII: The ovary has developed maturely, covers the stomach, presents dark green and golden brown, and mature ovules are visible;

[0050] Stage VIII: The ovary has ovulated, and is translucent.

[0051] Table 1: Effects of different treatments on ovary development of female prawns

[0052] Group GSI / % Stage Ⅲ Stage Ⅳ Stage Ⅴ Stage Ⅵ Stage Ⅶ Stage Ⅷ Maturity rate Synchronous maturity rate Experimental group 1 0.631 0 0 0 1 8 1 100％ 80％ Experimental group 2 0.540 0 0 1 1 5 3 90％ 50％ Experimental group 3 0.481 0 0 3 3 4 0 70％ 40％ Control group 0.412 0 1 3 4 2 0 60％ 20％

[0053] As shown in Table 1, the ovary development of female prawns is changed to different degrees after different treatments. The mature rate of female prawns in experimental group 1 reaches 100%, and the synchronous mature rate is 80%, which indicates that water flow acclimation by adjusting water flow speed and temperature acclimation, and combined with intensified feeding of the nutritional enhancer during water flow acclimation, are beneficial to accumulation of nutritional substances in the hepatopancreas tissue of female prawns, and promote synchronous development and maturation of the ovary; the mature rate of female prawns in experimental group 2 is 90%, but the synchronous mature rate is low, which is 50%, and the number of female prawns in stage VIII is relatively large, which also indicates that appropriate water flow acclimation and temperature acclimation form an environment suitable for development of female prawns, which causes the female prawns to grow and develop too fast, and the ovary development is not synchronous; the synchronous mature rate of female prawns in experimental group 3 is 40%, which indicates that the nutritional enhancer can improve the resistance of female prawns during water flow acclimation combined with intensified feeding, and then promote energy intake of female prawns under environmental stress, accelerate synthesis and accumulation of nutritional substances required for development of the ovary, and improve the ovary development.

[0054] Example 2

[0055] S1 temporary breeding: male parent prawns and female parent prawns are temporarily bred in a pond at a ratio of 1:1 for 5 days;

[0056] S2 acclimation and intensification: water flow acclimation by adjusting water flow speed and temperature acclimation are performed, high-speed water flow acclimation is performed at a water flow speed of 1.2-1.5 m / s for 7 days, and then low-speed water flow acclimation is performed at a water flow speed of 0.4-0.6 m / s for 7 days, water flow acclimation is performed 4 times a day, and each time lasts for 15 min;

[0057] Meanwhile, the nutritional enhancer is fed during water flow acclimation, and the feeding amount of the nutritional enhancer is 1% of the weight of the parent prawns;

[0058] The nutritional enhancer is composed of 28 parts of taurine, 17 parts of arachidonic acid, 12 parts of choline chloride and 12 parts of cuttlebone powder;

[0059] The initial temperature is set to 18 DEG C, the temperature is increased by 0.5 DEG C per day, when the temperature is increased to 22 DEG C, the temperature increasing is stopped, the water temperature of 22 DEG C is maintained for 3 days, then the water temperature is increased by 0.5 DEG C per day, when the temperature is increased to 25 DEG C, the temperature increasing is stopped, the water temperature of 25 DEG C is maintained for 4 days, finally the water temperature is increased by 0.5 DEG C per day, until the target parent prawn is harvested.

[0060] Through detection, the GSI is 0.614%, and dead prawns appear.

[0061] Example 3

[0062] S1 temporary breeding: the male parent prawn and the female parent prawn are temporarily bred in a pool at 1:1 for 5 days;

[0063] S2 acclimation and strengthening: the water flow velocity is adjusted for water flow acclimation and temperature acclimation, first, the water flow acclimation is performed for 7 days at a high-speed water flow acclimation water flow velocity of 1.2-1.5 m / s, then the water flow acclimation is performed for 7 days at a low-speed water flow acclimation water flow velocity of 0.4-0.6 m / s, the water flow acclimation is performed 3 times per day, and each time for 20 min;

[0064] Meanwhile, the nutritional enhancer is fed for strengthening breeding when the water flow acclimation is performed, and the feeding amount of the nutritional enhancer is 0.8% of the weight of the parent prawn;

[0065] The nutritional enhancer is composed of 32 parts of taurine, 22 parts of arachidonic acid, 16 parts of phosphatidylserine and 58 parts of cuttlebone powder;

[0066] The initial temperature is set to 19 DEG C, the temperature is increased by 0.5 DEG C per day, when the temperature is increased to 21 DEG C, the temperature increasing is stopped, the water temperature of 21 DEG C is maintained for 3 days, then the water temperature is increased by 0.5 DEG C per day, when the temperature is increased to 24 DEG C, the temperature increasing is stopped, the water temperature of 24 DEG C is maintained for 3 days, finally the water temperature is increased by 0.5 DEG C per day, until the target parent prawn is harvested.

[0067] The above only describes the preferred embodiments of the present application and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for inducing synchronous sexual maturation in broodstock shrimp, characterized in that, Includes the following steps: S1 Temporary Holding: Male and female broodstock shrimp are temporarily held in the pond; S2 Acclimation and Enhancement: Adjust the water flow speed for water flow acclimation and temperature acclimation. Set the water flow speed to 0.4~1.5m / s. During water flow acclimation, add nutrient fortifiers for enhanced feeding. The components of the nutritional fortifier include: taurine, arachidonic acid, phosphatidylserine, and cuttlebone powder; Perform water flow training 2-4 times a day, 10-20 minutes each time; The water flow acclimatization process lasted 12-16 days, including 6-8 days of high-speed water flow acclimatization and 6-8 days of low-speed water flow acclimatization. High-speed water flow acclimatization was performed first, followed by low-speed water flow acclimatization. The water flow velocity for high-speed water flow acclimatization was 1.2-1.5 m / s, and the water flow velocity for low-speed water flow acclimatization was 0.4-0.6 m / s. Set the temperature to 18~19℃, and increase it by 0.4~0.6℃ per day until it reaches 27~28℃.

2. The method for promoting synchronous sexual maturation of broodstock shrimp according to claim 1, characterized in that, The temperature rise includes three gradual transitional stages: the first stage is to raise the temperature to 21~22℃, the second stage is to raise the temperature to 24~25℃, and the third stage is to raise the temperature to 27~28℃.

3. The method for promoting synchronous sexual maturation of broodstock shrimp according to claim 2, characterized in that, The first stage is: when the temperature reaches 21~22℃, stop heating and maintain the water temperature at 21~22℃ for 3~4 days; The second stage is: when the temperature reaches 24~25℃, stop heating and maintain the water temperature at 24~25℃ for 3~4 days; The third stage is to raise the temperature to 27-28℃ until the target parent shrimp are harvested.

4. The method for promoting synchronous sexual maturation of broodstock shrimp according to claim 1, characterized in that, The nutritional fortifier comprises the following components by weight: 24-32 parts taurine, 12-22 parts arachidonic acid, 8-16 parts phosphatidylserine, and 50-58 parts cuttlebone powder.

5. The method for promoting synchronous sexual maturation of broodstock shrimp according to claim 1, characterized in that, The amount of nutrient fortifier added to the feed should be 0.8-1.2% of the weight of the broodstock shrimp.

6. The method for promoting synchronous sexual maturation of broodstock shrimp according to any one of claims 1 to 5, characterized in that, The broodstock is the giant freshwater prawn (Macrobrachium rosenbergii).