Method for reducing air exposure oxidative damage of juvenile golden trevally

Abstract

The invention belongs to the technical field of fish culture, and particularly discloses a method for reducing air exposure oxidative damage of golden trevally juvenile fish, air exposure is performed after anesthesia pretreatment, and the anesthesia treatment can block a typical stress pathway of a fish body to air exposure, reduce excessive activation or inhibition of an anti-oxidation system and maintain physiological balance in the body; the activity of antioxidant enzyme in the muscle of the juvenile golden trevally can be kept stable, MDA accumulation is reduced, and tissue damage caused by oxidation imbalance is avoided. The method can be realized only through conventional anesthesia pretreatment without complex equipment, and is suitable for large-scale application in aquaculture, transportation and other scenes.

Description

Technical Field

[0001] The invention belongs to the technical field of fish breeding, and particularly relates to a method for reducing oxidative damage caused by air exposure of juvenile yellow oriole toothless scad. Background Art

[0002] Fish inevitably experience short- or long-term exposure to air during aquaculture, seedling transportation, and manual handling (such as sorting and counting). Air exposure disrupts fish's physiological balance, triggering stress responses and leading to the accumulation of reactive oxygen free radicals. This in turn induces abnormal fluctuations in antioxidant enzyme systems (such as SOD and GSH-Px), resulting in oxidative damage. Oxidative damage directly impacts fish growth performance, immune function, and survival, particularly in juveniles.

[0003] The yellowtail trevally (Gnathanodon speciosus) is a marine fish of high economic value. Its juveniles are frequently exposed to air stress during aquaculture and transportation. Existing technologies lack effective mitigation methods for oxidative damage caused by air exposure in yellowtail trevally juveniles. Therefore, developing a simple, effective, and effective mitigation method is crucial for improving aquaculture profitability. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes a method for reducing oxidative damage of oriole toothless scad juveniles exposed to air, so as to solve the problem that oriole toothless scad juveniles are prone to obvious oxidative damage when exposed to air.

[0005] The method of reducing oxidative damage of juvenile yellowtail trevally exposed to air comprises the following steps:

[0006] S1. Soaking the juvenile yellowtail trevally in an anesthetic solution until the trevally is in an anesthetized state;

[0007] S2, remove the anesthetized juvenile fish from the water and perform targeted manipulation;

[0008] S3. After the operation, move the fish into clean water for recovery.

[0009] The anesthetic in S1 is MS-222 with a concentration of 80-100 mg / L. The anesthesia state is that the fish loses its balance but the gill cover moves regularly.

[0010] The anesthesia time in S1 is within 3 minutes.

[0011] The time of the target operation in S2 is within 180 seconds.

[0012] The beneficial effects of the present invention are:

[0013] Compared to existing technologies, this method uses anesthesia pretreatment followed by air exposure. This anesthesia treatment blocks typical stress pathways in fish exposed to air, reduces overactivation or inhibition of antioxidant systems, and maintains physiological balance. It also stabilizes antioxidant enzyme activity in the muscles of juvenile yellowtail scad, reduces MDA accumulation, and avoids tissue damage caused by oxidative imbalance. This method, which requires no complex equipment and can be achieved solely through conventional anesthesia pretreatment, is suitable for large-scale application in aquaculture, transportation, and other scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments.

[0015] Figure 1 Graphs showing changes in antioxidant indicators under direct air exposure in the examples, where a is a graph showing changes in GSH-Px activity, b is a graph showing changes in MDA content, c is a graph showing changes in SOD activity, and d is a graph showing changes in T-AOC.

[0016] Figure 2 Graphs showing changes in antioxidant indices after anesthesia treatment under air exposure in the examples, wherein a is a graph showing changes in GSH-Px activity, b is a graph showing changes in MDA content, c is a graph showing changes in SOD activity, and d is a graph showing changes in T-AOC. DETAILED DESCRIPTION

[0017] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. In addition, the technical features involved in the various embodiments described below can be combined with each other as long as they do not conflict with each other.

[0018] Environmental control: The water temperature was maintained at (28±1)℃ and the pH was maintained at (7.8-8.2). These conditions are suitable for the survival of juvenile yellowtail trevally and can reduce the interference of environmental factors on the experimental results.

[0019] Comparative Example 1: The juvenile yellow oriole toothless trevally is exposed to air directly.

[0020] Changes in antioxidant enzyme activities in muscle tissue of juvenile yellowtail trevally Figure 1As shown in the results, glutathione peroxidase (GSH-Px) activity initially increased and then decreased with treatment time, with significant differences observed between the 0s, 60s, 180s, and 90s air exposure groups (P < 0.05). Malondialdehyde (MDA) content initially increased and then decreased with treatment time, but no significant differences were observed between the different air exposure time groups (P > 0.05). Superoxide dismutase (SOD) expression levels showed significant differences between the 0s, 60s, 90s, and 180s air exposure groups (P < 0.05). Total antioxidant capacity (T-AOC) did not differ significantly between the different air exposure time groups (P > 0.05). Direct air exposure at different times primarily affected glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities, with no significant effects on MDA and T-AOC.

[0021] Example 1

[0022] The juveniles were anesthetized with 50mg / L MS-222 for 3 minutes. The anesthetized juveniles were exposed to air for 180 seconds. Figure 2 As shown. Glutathione peroxidase (GSH-Px) levels initially decreased and then increased over time, with no significant differences observed between the different anesthesia time groups (P>0.05). Malondialdehyde (MDA) levels initially increased and then decreased over time, but no significant differences were observed between the different anesthesia time groups (P>0.05). Superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) levels did not differ significantly between the different anesthesia time groups (P>0.05), and their activities showed no significant trend. It can be seen that the effects of air exposure at different times after anesthesia on glutathione peroxidase (GSH-Px), malondialdehyde (MDA), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) were not significant, that is, anesthesia can reduce the effects of long-term air exposure on glutathione peroxidase (GSH-Px), malondialdehyde (MDA), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) in the muscles of juvenile yellow oriole toothless scad, that is, compared with direct air exposure, anesthesia followed by air exposure can reduce the stress response of juvenile yellow oriole toothless scad during air exposure.

[0023] Conclusion: Under the conditions of water temperature (28±1)℃ and pH (7.8-8.2), the experiment determined the effects of direct air exposure and air exposure after anesthesia and re-wetting on the activities of antioxidant enzymes (superoxide dismutase SOD, malondialdehyde MDA, glutathione peroxidase GSH-Px and total antioxidant capacity T-AOC) in the muscles of juvenile yellowtail scad (Gnathanodon speciosus). The results showed that in the direct air exposure treatment without anesthesia: GSH-Px activity and SOD activity were significantly different between the different air exposure time groups, and changed with the extension of air exposure time. After 120 minutes of re-immersion recovery, the activities of these enzymes failed to return to the level before air exposure (corresponding to the air exposure 0s group in the data, the same below) (P<0.05); although the MDA content fluctuated, there was no significant difference, and it returned to the level before air exposure after 120 minutes of re-immersion recovery; after 180 seconds of air exposure treatment, the MDA and GSH-Px activities of the juvenile oriole toothless scad were significantly higher than the level before air exposure (P<0.05), while the SOD activity was significantly lower than the level before air exposure (P<0.05), indicating that direct air exposure for 180 seconds showed obvious oxidative damage.

[0024] The method of anesthesia followed by air exposure was used. After 180 seconds of air exposure after anesthesia, there was no significant difference in GSH-Px activity, MDA content, SOD activity and T-AOC activity in the muscle, indicating that anesthesia inhibited the typical stress response of fish to air exposure. In the anesthesia followed by air exposure group, the MDA content reached the maximum value 60 minutes after recovery in water, which was significantly higher than that before air exposure (P<0.05). After 120 minutes of anesthesia recovery, the other enzyme activity values ​​and MDA of each experimental group were able to return to the levels before air exposure.

[0025] Therefore, the levels of antioxidant enzymes in juvenile yellowtail trevally after anesthesia were higher than those after direct air exposure. Anesthesia followed by air exposure can reduce oxidative damage more than direct air exposure.

[0026] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. The preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification.

Claims

1. A method for reducing oxidative damage in juvenile yellowtail trevally exposed to air, characterized in that: The following steps are involved: S1. Soaking the juvenile yellowtail trevally in an anesthetic solution until the trevally is in an anesthetized state; S2, remove the anesthetized juvenile fish from the water and perform targeted manipulation; S3. After the operation, move the fish into clean water for recovery.

2. The method for reducing oxidative damage caused by air exposure in juvenile yellowtail trevally according to claim 1, characterized in that: The anesthetic in S1 is MS-222 with a concentration of 80-100 mg / L. The anesthesia state is that the fish loses its balance but the gill cover moves regularly.

3. The method for reducing oxidative damage caused by air exposure in juvenile yellowtail trevally according to claim 2, characterized in that: The anesthesia time in S1 is within 3 minutes.

4. The method for reducing oxidative damage caused by air exposure in juvenile yellowtail trevally according to claim 3, characterized in that: The time of the target operation in S2 is within 180 seconds.

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