Method for improving growth and development speed and antibacterial ability of crassostrea gigas larvae by using taurine

Abstract

The invention relates to an aquaculture technology, in particular to a method for improving growth and development speed and antibacterial ability of crassostrea gigas larvae by using taurine. The crassostrea gigas shell top larvae are soaked with taurine, so that the growth of the larvae can be promoted, the attachment and metamorphosis process can be accelerated, and the survival rate after vibrio splendidus infection can be improved. The taurine is proved to be capable of improving the growth and development speed and the immune defense capability of the crassostrea gigas larvae, and has wide application prospects in the aspects of shortening the crassostrea gigas breeding period, improving the breeding success rate and the quality of the larvae, promoting the green development of the crassostrea gigas breeding industry and the like.

Description

Technical Field

[0001] The invention relates to aquaculture technology, in particular to a method for improving the growth and development speed and antibacterial ability of oyster larvae by utilizing taurine. Background Art

[0002] The giant oyster (Crassostrea gigas) is the main farmed shellfish in the northern coastal areas of my country, playing an important role in ensuring the supply of high-quality protein and promoting the development of the fishery economy. In recent years, due to factors such as germplasm degradation, deterioration of the marine environment and an imperfect disease prevention and control system, the disease problem in the seed breeding stage of the giant oyster has become increasingly serious, and the success rate of seed breeding and seed quality have declined year by year, seriously restricting the high-quality development of the oyster farming industry. Improving the growth and development speed of larvae and their ability to resist diseases and stress 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 adding an appropriate amount of taurine to feed can improve the growth performance and immune capacity of aquatic animals such as grass carp, golden pomfret, Japanese swamp shrimp, and square-headed snail. In addition, taurine also has the effects of improving feed palatability and enhancing appetite, and therefore has received more and more attention in the field of aquaculture. However, there are few reports on the application of taurine in the breeding stage of shellfish seedlings. Summary of the invention

[0004] The present invention aims to provide a method for improving the growth and development speed and antibacterial ability of long oyster larvae by using taurine. The method can improve the growth and development speed and antibacterial ability of long oyster larvae, shorten the seedling raising period, and reduce the production cost, which has important practical significance for promoting the healthy and sustainable development of the oyster aquaculture industry.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for improving the growth and development speed and antibacterial ability of long oyster larvae by using taurine, wherein the long oyster shell top larvae are soaked in taurine to promote the growth of the larvae, accelerate the attachment and metamorphosis process, and improve the survival rate after infection by Vibrio splendens.

[0007] Place the oyster shell larvae in a 10 -7 The samples were immersed in filtered seawater containing M taurine for 12 hours.

[0008] During the taurine soaking treatment, the water temperature is 21-23° C., 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 the larvae during the taurine soaking treatment is 2 to 4 larvae / mL.

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

[0011] During the taurine soaking treatment, no feeding is performed on the larvae.

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

[0013] The present invention soaks the oyster larvae in taurine of a specific concentration, which can significantly improve the growth and development speed and antibacterial ability of the larvae, shorten the seedling raising period, improve the seedling raising success rate and seedling quality, and has great economic value. In addition, taurine is green, non-toxic, low-priced and easy to obtain, and has significant advantages in large-scale application and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The data of shell height (A) and shell length (B) of oyster shell larvae after soaking in different concentrations of taurine provided in Example 1 of the present invention. -7 , 10 -6 and 10 -5 Respectively represents the concentration of taurine is 10 -7 M, 10 -6 M and 10 -5 M. Different letters indicate significant differences (p<0.05).

[0015] Figure 2 The eye spot appearance rate of the oyster shell larvae after soaking in different concentrations of taurine provided in Example 2 of the present invention. -7 , 10 -6 and 10 -5 Respectively represents the concentration of taurine is 10 -7 M, 10 -6 M and 10 - 5 M. Different letters indicate significant differences (p<0.05).

[0016] Figure 3 The larvae of oyster shells treated with different concentrations of taurine provided in Example 3 of the present invention were exposed to Vibrio splendens (2×10 7 CFU / L) survival rate after 48h infection. -7 , 10 -6 and 10 -5 Respectively represents the concentration of taurine is 10 -7 M, 10 -6 M and 10 -5M. Different letters indicate significant differences (p<0.05). DETAILED DESCRIPTION

[0017] The specific implementation modes of the present invention are further described below in conjunction with examples. It should be noted that the specific implementation modes described here are only for illustrating and explaining the present invention, and are not limited to the present invention.

[0018] The present invention utilizes taurine, a natural amino acid that is low in cost and easily available, to soak the oyster shell larvae, which can promote the growth of the larvae, accelerate the attachment and metamorphosis process, and improve the survival rate after Vibrio splendens infection, thereby achieving the purpose of reducing seedling cultivation costs and improving seedling quality.

[0019] Example 1: Effect of taurine on the growth promotion of larvae

[0020] The larvae of long oyster shells were collected and divided into four groups, which were laid in the culture tanks and placed in the water tanks under taurine concentrations of 0 M, 10 -7 M, 10 -6 M and 10 -5 The 0M treatment group was used as the control group (Control). After 12 hours of immersion treatment, the seawater in the tank was replaced with normal filtered seawater, and the growth of the larvae was counted on the 10th day of the experiment. The larval density was 2-4 / 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 7.7-8.0 mg / L. No feeding was done during the immersion treatment. After 12 hours of treatment, Isochrysis and Chlorella were fed three times a day, and the water was fully changed every two days.

[0021] Experimental results: On the 10th day, 10 -7 The shell height and shell length of the larvae in group M were 298.98 μm and 276.79 μm, which were 1.09 and 1.08 times those of the control group, respectively (p<0.05). -6 Group M and 10 -5 There was no significant difference between the M group and the control group ( Figure 1 ).

[0022] Example 2: The promoting effect of taurine on larval eyespot formation

[0023] The larvae of long oyster shells were collected and divided into four groups, which were laid in the culture tanks and kept in the water under taurine concentrations of 0 M, 10 -7 M, 10 -6 M and 10 -5The 0M treatment group was immersed in seawater of 100 mL, of which the 0M treatment group was the control group (Control). After 12 h of immersion treatment, the seawater in the water tank was replaced with normal filtered seawater. The breeding environment and conditions were the same as those in Example 1. On the 10th day of the experiment, 100 mL of seawater was taken from each group, and the larvae were enriched using a 200-mesh sieve, and the eye spot appearance rate was counted under an optical microscope, with three replicates for each group.

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

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

[0026] The larvae of long oyster shells were collected and divided into four groups, which were laid in the culture tanks and placed in the water tanks under taurine concentrations of 0 M, 10 -7 M, 10 -6 M and 10 -5 The 0M treatment group was used as the control group (Control). After 12 h of immersion, the seawater in the tank was replaced with normal filtered seawater. The culture environment and conditions were the same as those in Example 1. After 10 days, 1×10 4 The larvae were placed in a 10L plastic bucket and stimulated by soaking Vibrio splendens at a concentration of 2×10 7 CFU / L, the survival rate of the shell-top larvae was calculated 48 hours after bacterial stimulation.

[0027] Experimental results: After stimulation with Vibrio splendens, -7 Group M, 10 -6 Group M and 10 -5 The survival rates of the larvae in group M were 89.55%, 88.84% and 84.46%, which were 1.46, 1.45 and 1.37 times that of the control group, respectively (p < 0.05) ( Figure 3 ).

Claims

1. A method for improving the growth rate and antibacterial ability of oyster larvae by using taurine, characterized in that: The larvae of the long-shelled oyster were treated with taurine.

2. The method for improving the growth rate and antibacterial ability of oyster larvae by using taurine according to claim 1, characterized in that: The oyster shell larvae are placed in a 10 -7 M taurine in the aquaculture seawater and soak for 12 hours.

3. The method for improving the growth and development speed and antibacterial ability of oyster larvae by using taurine according to claim 1, characterized in that: During the taurine treatment, the water temperature is 21-23° C., the salinity is 30-32, the pH value is 7.8-8.0, and the dissolved oxygen is 7.7-8.0 mg / L.

4. The method for improving the growth rate and antibacterial ability of oyster larvae by using taurine according to claim 1, characterized in that: The larvae density during the taurine soaking treatment is 2 to 4 larvae / mL.

5. The method for improving the growth rate and antibacterial ability of oyster larvae by using taurine according to claim 1, characterized in that: After the taurine soaking treatment, the larvae were further cultured using filtered seawater.

6. The method for improving the growth rate and antibacterial ability of oyster larvae by using taurine according to claim 1, characterized in that: During the taurine soaking treatment, no feeding is performed on the larvae.

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