A method for improving the growth and development speed and antibacterial capacity of long oyster larvae by using taurine

Abstract

The present application relates to aquaculture technology, in particular to a method for improving the growth and development speed and antibacterial ability of long oyster larvae by using taurine. The taurine soaking treatment of long oyster shell top larvae can promote the growth of larvae, accelerate the attachment metamorphosis process, and improve the survival rate after infection of Vibrio splendidus. The present application proves that taurine can improve the growth and development speed and immune defense ability of long oyster larvae, and has broad application prospects in shortening the oyster breeding cycle, improving the success rate and seed quality of breeding, promoting the green development of oyster culture industry, etc.

Description

TECHNICAL FIELD

[0001] The present application relates to the aquaculture technology, and in particular to a method for improving the growth and development speed and antibacterial capacity of Crassostrea gigas larvae by using taurine. BACKGROUND

[0002] Crassostrea gigas is the main cultured shellfish in the coastal areas of northern China, and plays an important role in ensuring high-quality protein supply and promoting the development of the fishery economy. In recent years, due to factors such as genetic degradation, environmental deterioration, and imperfect disease prevention and control system, the disease problem at the larval rearing stage of Crassostrea gigas has become increasingly serious, and the success rate of larval rearing and the quality of larval seed have decreased year by year, which has seriously restricted the high-quality development of the oyster culture industry. Improving the growth and development speed and the disease resistance and stress resistance of larvae has become a key way to solve this problem.

[0003] Taurine is a sulfur-containing amino acid with multiple physiological functions such as anti-inflammatory, antioxidant, and osmotic pressure regulation. Studies have found that appropriate addition of taurine in feed can improve the growth performance and immune capacity of aquatic animals such as grass carp, goldfish, Japanese marsh shrimp, and Thais clavigera. In addition, taurine also has the effects of improving feed palatability and enhancing appetite, and thus has received more and more attention in the field of aquaculture. However, there are few reports on the application of taurine at the larval rearing stage of shellfish. SUMMARY

[0004] The present application aims to provide a method for improving the growth and development speed and antibacterial capacity of Crassostrea gigas larvae by using taurine. This method can improve the growth and development speed and antibacterial capacity of Crassostrea gigas larvae, shorten the larval rearing period, and reduce production costs, which has important practical significance for promoting the healthy and sustainable development of the oyster culture industry.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0006] A method for improving the growth and development speed and antibacterial capacity of Crassostrea gigas larvae by using taurine, which can promote the growth of larvae, accelerate the process of attachment metamorphosis, and improve the survival rate after Vibrio splendidus infection.

[0007] Place the Crassostrea gigas D-larvae in filtered seawater containing 10 -7 M taurine for 12 hours of soaking treatment.

[0008] The water temperature during taurine soaking treatment is 21-23℃, the salinity is 30-32, the pH value is 7.8-8.0, and the dissolved oxygen is 7.7-8.0 mg / L.

[0009] The density of larvae during taurine soaking treatment is 2-4 per mL.

[0010] After the taurine soaking treatment, the seawater containing taurine is replaced with filtered seawater, and the larva cultivation is continued.

[0011] During the taurine soaking treatment, the larva is not fed with bait.

[0012] Compared with the prior art, the present application has the following advantages:

[0013] The present application can significantly improve the growth and development speed and the antibacterial ability of the larva of Pinctada martensii, shorten the breeding cycle, improve the breeding success rate and the quality of the seedling, and has great economic value. In addition, taurine is green, non-toxic, low in price and easy to obtain, and has significant advantages in large-scale application and promotion. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The shell height (A) and shell length (B) data of the shell top larva of Pinctada martensii after taurine soaking treatment at different concentrations according to Example 1 of the present application are provided. Control represents the control group, 10 -7 , 10 -6 and 10 -5 represent the concentration of taurine of 10 -7 M, 10 -6 M and 10 -5 M respectively. Different letters represent significant difference (p<0.05).

[0015] Figure 2 The eye spot appearance rate of the shell top larva of Pinctada martensii after taurine soaking treatment at different concentrations according to Example 2 of the present application is provided. Control represents the control group, 10 -7 , 10 -6 and 10 -5 represent the concentration of taurine of 10 -7 M, 10 -6 M and 10 - 5 M respectively. Different letters represent significant difference (p<0.05).

[0016] Figure 3 The survival rate of the shell top larva of Pinctada martensii after Vibrio splendidus (2x10 7 CFU / L) infection for 48h after taurine soaking treatment at different concentrations according to Example 3 of the present application is provided. Control represents the control group, 10 -7 , 10 -6 and 10 -5 represent the concentration of taurine of 10 -7 M, 10 -6 M and 10 -5M Different letters represent significant differences (p < 0.05). DETAILED DESCRIPTION

[0017] The specific embodiments of the present application are further described in the following examples, it should be noted that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not limited to the present application.

[0018] The present application uses taurine, a natural amino acid with low cost and easy to obtain, to soak the juvenile of Pinctada martensii, which can promote the growth of the juvenile, speed up the process of attachment metamorphosis, and improve the survival rate after Vibrio splendidus infection, so as to achieve the purpose of reducing the cost of breeding and improving the quality of seedlings.

[0019] Example 1: Promoting effect of taurine on the growth of juvenile

[0020] The juvenile of Pinctada martensii was collected and evenly divided into four groups, which were respectively laid in the breeding tank and soaked in seawater with taurine concentration of 0M, 10 -7 M, 10 -6 M and 10 -5 M, wherein the 0M treatment group was the control group (Control). After 12h of soaking treatment, the seawater in the tank was replaced with normal filtered seawater, and the growth of the juvenile was counted on the 10th day of the experiment. The density of the juvenile was 2-4 per mL, the water temperature was 21-23℃, the salinity was 30-32, the pH value was 7.8-8.0, and the dissolved oxygen was 7.7-8.0mg / L. No feeding was performed during the soaking treatment, and after 12h of treatment, the juvenile was fed with Isochrysis galbana and Chlorella sp. three times a day, and the water was changed once every two days.

[0021] Experimental results: on the 10th day, the shell height of the juvenile in the 10 -7 M group was 298.98μm, and the shell length was 276.79μm, which were 1.09 times and 1.08 times of the control group (p<0.05), respectively, the shell height of the juvenile in the 10 -6 M group and the 10 -5 M group had no significant difference compared with the control group (p>0.05). Figure 1

[0022] Example 2: Promoting effect of taurine on the formation of eye spots of juvenile

[0023] The juvenile of Pinctada martensii was collected and evenly divided into four groups, which were respectively laid in the breeding tank and soaked in seawater with taurine concentration of 0M, 10 -7 M, 10 -6 M and 10 -5 ​M group was the control group (Control). After 12 h of soaking treatment, the seawater in the water tank was replaced with normal filtered seawater. The breeding environment and conditions were the same as in Example 1. On the 10th day of the experiment, 100 mL of seawater was taken from each group, the larvae were enriched using a 200-mesh silk screen, and placed under an optical microscope to count the occurrence rate of eye spots, with three replicates for each group.

[0024] Experimental results: 10 -7 The occurrence rate of eye spots in the M group was 47.77%, which was 2.58 times that of the control group (p<0.05), 10 -6 The M group and 10 -5 The M group and the control group had no significant difference Figure 2 ).

[0025] Example 3: Taurine improves the survival rate of larvae after Vibrio splendidus infection

[0026] Top shell larvae of Pinctada martensii were collected and divided into four groups, which were placed in breeding tanks with taurine concentrations of 0 M, 10 -7 M, 10 -6 M, and 10 -5 M. The 0 M treatment group was the control group (Control). After 12 h of soaking treatment, the seawater in the water tank was replaced with normal filtered seawater, and the breeding environment and conditions were the same as in Example 1. After 10 days, 1 x 10 4 Top shell larvae were selected from each treatment group and placed in a 10 L plastic bucket for Vibrio splendidus soaking stimulation. The concentration of Vibrio splendidus was 2 x 10 7 CFU / L, and the survival rate of top shell larvae was counted after 48 h of bacterial stimulation.

[0027] Experimental results: After Vibrio splendidus stimulation, 10 -7 M group, 10 -6 M group, and 10 -5 The survival rates of the M group, 10 Figure 3 ).

Claims

1. A method for improving the growth and development speed and antibacterial ability of Pinctada martensii larvae by using taurine, characterized by the following steps: The long oyster shell top larvae are subjected to taurine soaking treatment; the taurine soaking treatment is placing the long oyster shell top larvae in 10 -7 M taurine in the breeding seawater for 12 h. ​ 2. The method for improving the growth and development speed and antibacterial ability of Pinctada martensii larvae by taurine according to claim 1, characterized in that: The water temperature during the taurine soaking treatment is 21-23 ℃, the salinity is 30-32, the pH value is 7.8-8.0, and the dissolved oxygen is 7.7-8.0 mg / L.

3. The method for improving the growth and development speed and antibacterial ability of Pinctada martensii larvae by taurine according to claim 1, characterized in that: The density of the larvae during the taurine soaking treatment is 2-4 per mL.

4. The method for improving the growth and development speed and antibacterial ability of Pinctada martensii larvae by taurine according to claim 1, characterized in that: After the taurine soaking treatment, the larvae are further cultivated in filtered seawater.

5. The method for improving the growth and development speed and antibacterial ability of Pinctada martensii larvae by taurine according to claim 1, characterized in that: During the taurine soaking treatment, the larvae are not fed with feed.

Images