Illumination regulation and control method for promoting synchronous and rapid maturation of gonads of haliotis discus hannai

Abstract

The invention discloses an illumination regulation and control method for promoting synchronous and rapid maturation of gonads of haliotis discus hannai, and belongs to the technical field of aquatic seedling breeding. Rapid and synchronous development of ovaries of the haliotis discus hannai is promoted by artificially regulating and controlling the light intensity and the light period in the culture environment in the development stage of the ovaries of the haliotis discus hannai; the illumination intensity is maintained in a range of 1.5 + / -0.5 [mu] mol / m < 2 > / s, the illumination period is 18 h illumination and 6 h darkness, and 24 h is taken as a cycle period. According to the method, the illumination intensity and period in the breeding environment are manually regulated and controlled, so that the light environment requirement of the female haliotis discus hannai in the gonad development period is met, the gonad development speed is increased, the difference between gonad development individuals is reduced, synchronous gonad maturation of haliotis discus hannai groups is achieved, the breeding period is effectively shortened, and the breeding cost is reduced. The large-scale production efficiency of the fertilized eggs and the stability of fry breeding are improved.

Description

Technical Field

[0001] This invention belongs to the field of industrialized seedling breeding technology of abalone, specifically involving a light regulation method to promote the synchronous and rapid maturation of gonads in abalone. Background Technology

[0002] Light is a crucial regulatory signal in the biological world and is often a key factor influencing biological rhythms. Organisms use variations in photoperiod or day length as cues to initiate life history events such as diapause, migration, reproduction, and development. Different photoperiods can affect the development, behavior, and physiology of individual organisms. In aquatic ecosystems, photoperiod determines the optimal time for growth, reproduction, migration, and other behavioral and physiological activities, making it one of the key environmental factors affecting the growth, development, and survival of aquatic organisms.

[0003] Abalone is a widely distributed marine gastropod and one of the world's most valuable fishery products. In artificial breeding of abalone, the ratio of female to male abalone to spawners is typically 8:1, meaning that the sperm produced by one male abalone can fertilize eight females. Therefore, the demand for female abalone far exceeds that for males. However, with the continuous development of the abalone farming industry, problems such as asynchronous gonadal development and large-scale mortality due to weakened constitution after concentrated gonadal release under high-density cultivation conditions have gradually emerged, severely hindering the healthy and sustainable development of the industry.

[0004] Currently, the control of light environment in abalone seedling breeding lacks sufficient attention and technical support. Establishing a simple method for controlling light environment is of great significance for achieving synchronous and rapid maturation of gonads in abalone populations, effectively shortening the breeding cycle, improving the efficiency of large-scale egg production, and enhancing the stability of seedling cultivation. Summary of the Invention

[0005] To overcome the problems of asynchronous gonadal development in female abalone seedlings and large-scale mortality due to weakened constitution after concentrated gonadal release under high-density cultivation conditions, this invention provides a light regulation method to promote synchronous and rapid maturation of gonads in abalone. This method can significantly improve the gonadal index of female abalone and reduce the differences in gonadal development between individuals, which is of great significance for improving the seedling efficiency of abalone.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for light regulation to promote the synchronous and rapid maturation of gonads in Abalone fasciatus involves artificially controlling the light intensity and photoperiod in the culture environment of female Abalone fasciatus to promote the synchronous and rapid maturation of their ovaries; the light intensity is maintained at 1.5 ± 0.5 μmol / m². 2 Within a range of / s, the light cycle is 18 hours of light followed by 6 hours of darkness, with a cycle of 24 hours.

[0007] Preferably, the method specifically includes the following steps: (1) Select wrinkled abalone in the ovarian development stage of the proliferation period and raise them in an indoor factory-style flow water or recirculating water mode. (2) An artificial light source, consisting of LED lights, is placed above the aquaculture pond. During the lighting period, the light intensity at the bottom of the aquaculture pond is maintained at 1.5 ± 0.5 μmol / m. 2 Within the range of / s; (3) The lighting period is from 6:00 to 24:00 every day, and the rest of the time is dark; (4) The spectrum of LED lighting is the full spectrum.

[0008] As a preferred option, full-spectrum LED luminaires have a wavelength range of 430-760nm.

[0009] Preferably, the transition time between light and darkness is 20-30 minutes.

[0010] The transition between light and darkness should be gradual to avoid sudden environmental changes that could irritate the wrinkled abalone.

[0011] Preferably, the dissolved oxygen in the culture water during the culture stage is greater than 6 mg / L, pH is 7.5-8, water temperature is 18-20℃, and salinity is 29-31.

[0012] As a preferred option, feed fresh Gracilaria or kelp once a day.

[0013] Preferably, the feeding amount is 3-5% of the abalone's wet body weight.

[0014] Preferably, the initial stocking density of the female abalone is 35-40 individuals / m². 2 .

[0015] Appropriate initial stocking density can avoid overcrowding stress while ensuring stocking efficiency.

[0016] Preferably, a wireless controller can be used to remotely control the light source to reduce the impact of human activities on the farmed organisms.

[0017] The beneficial effects of this invention are: This invention, based on the gonadal development characteristics of the wrinkled abalone, meets its light environment requirements, especially specific photoperiods, during gonadal development by artificially controlling illumination. This significantly improves the gonadal index of female wrinkled abalone and reduces inter-individual differences in gonadal development, thereby enhancing the productivity and economic benefits of aquaculture enterprises, and has great application potential. Detailed Implementation

[0018] The present invention will be further described below with reference to specific implementation methods.

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The following non-limiting embodiments can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way.

[0020] Example 1 Three culture tanks with dimensions of 1 m × 1 m × 0.6 m were selected, each containing 40 abalone (Abalone fasciatus) as three replicates. The abalone shells used had a length of 6.17 ± 0.73 cm and a weight of 41.06 ± 3.63 g. These were individuals from the same batch after artificial spawning. The abalone were in the proliferative phase of ovarian development, meaning the ovaries mainly contained oogonia and stage I oocytes. Ooogonia were attached to the trabeculae, and the nucleoli of newly developing stage I oocytes began to appear. The oocytes attached to the trabeculae and extended towards the digestive glands, resembling teardrops in shape. They were cultured in an indoor, factory-style flow-through system for the following five months. During the culture period, the light environment control method described in this invention was used. The switching on and off of the lights was automatically controlled by a clock controller. The LED lighting used had a full spectrum, with a wavelength range of 430-760 nm. The light intensity at the bottom of the tank was 1.43 ± 0.24 μmol / m². 2 / s; the light cycle is 18 hours of light followed by 6 hours of darkness, with a 24-hour cycle; the lighting period is from 6:00 AM to 12:00 AM daily, with the remaining time spent in darkness; the transition time between light and darkness is 20-30 minutes. The water temperature is 19 ± 1℃, salinity is 30 ± 1, pH is 7.9, and dissolved oxygen concentration is >6.5 mg / L. The aquaculture water is taken from natural sea areas and used after sedimentation and sand filtration. Fresh Gracilaria is fed once daily at 5:00 PM at an amount equal to 3% of the abalone's wet body weight.

[0021] Comparative Example 1 The photoperiod during the aquaculture period was 12 hours of light and 12 hours of darkness. The abalone size and other aquaculture conditions were the same as in Example 1.

[0022] Comparative Example 2 The photoperiod during the aquaculture period was 24 hours of light and 0 hours of darkness. The abalone size and other aquaculture conditions were the same as in Example 1.

[0023] Comparative Example 3 The light intensity during the breeding period was 0.52 ± 0.07 μmol / m². 2 / s, the abalone specifications and other farming conditions are the same as in Example 1.

[0024] Comparative Example 4 The light intensity during the breeding period was 2.14 ± 0.26 μmol / m². 2 / s, the abalone specifications and other farming conditions are the same as in Example 1.

[0025] Comparative Example 5 The light intensity during the breeding period was 0.52 ± 0.07 μmol / m². 2 / s, the light cycle is 12 h of lighting and 12 h of darkness, and the abalone size and other farming conditions are the same as in Example 1.

[0026] Comparative Example 6 The light intensity during the breeding period was 0.52 ± 0.07 μmol / m². 2 / s, the light cycle is 24 h of illumination and 0 h of darkness, and the abalone size and other farming conditions are the same as in Example 1.

[0027] Comparative Example 7 The light intensity during the breeding period was 2.14 ± 0.26 μmol / m². 2 / s, the light cycle is 12 h of lighting and 12 h of darkness, and the abalone size and other farming conditions are the same as in Example 1.

[0028] Comparative Example 8 The light intensity during the breeding period was 2.14 ± 0.26 μmol / m². 2 / s, the light cycle is 24 h of illumination and 0 h of darkness, and the abalone size and other farming conditions are the same as in Example 1.

[0029] At the end of culture (150 days) in each group of Example 1, Comparative Example 1, and Comparative Example 2, the survival rate of abalone in each treatment group was counted. Subsequently, the abalone were dissected and the gonads were separated to calculate the gonad index. The calculation formula is as follows: Survival rate (%) = (Number of abalone at the end of the experiment / Number of abalone at the beginning of the experiment) * 100 Gonadal index (%) = (gonad wet weight / body weight wet weight)*100 Table 1

[0030] As shown in Table 1, the survival rate of the wrinkled abalone in Example 1 was very close to that of the abalone in all comparative examples, with no significant difference.

[0031] Table 2

[0032] As shown in Table 2, the gonadal index of female abalone cultured under the light mode described in Example 1 for 150 days was significantly higher than that of abalone in Comparative Examples 1 and 2. The light regulation described in this invention significantly improved the gonadal development of abalone and reduced inter-individual differences.

Claims

1. A light-regulating method for promoting the synchronous and rapid maturation of gonads in abalone with wrinkled discs, characterized in that: Artificially controlling the light intensity and photoperiod of the culture environment for female abalone promoted the synchronous and rapid maturation of their ovaries; the light intensity was maintained at 1.5 ± 0.5 μmol / m². 2 Within a range of / s, the light cycle is 18 hours of light followed by 6 hours of darkness, with a cycle of 24 hours.

2. The method according to claim 1, characterized in that: The method specifically includes the following steps: (1) Select wrinkled abalone in the ovarian development stage of the proliferation period and raise them in an indoor factory-style flow water or recirculating water mode. (2) An artificial light source, consisting of LED lights, is placed above the aquaculture pond. During the lighting period, the light intensity at the bottom of the aquaculture pond is maintained at 1.5 ± 0.5 μmol / m². 2 Within the range of / s; (3) The lighting period is from 6:00 to 24:00 every day, and the rest of the time is dark; (4) The spectrum of LED lighting is the full spectrum.

3. The method according to claim 2, characterized in that: The water used for aquaculture is taken from natural sea areas and filtered through sedimentation.

4. The method according to claim 2, characterized in that: During the aquaculture period, continuous aeration was maintained, with a water temperature of 19 ± 1℃, a salinity of 30 ± 1, and a pH range of 7.5-8.

0.

5. The method according to claim 2, characterized in that: Feed fresh gecko or kelp once a day.

6. The method according to claim 2, characterized in that: The feeding amount is 3-5% of the abalone's wet body weight.

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