Method for coral algae removal based on menthol exposure

Abstract

The invention discloses a method for coral algae removal based on menthol exposure, and belongs to the technical field of coral breeding. The method comprises the following steps: circularly domesticating corals in a light period and a dark period in sequence to complete algae removal; in the photoperiod, the coral is placed in seawater containing menthol to be subjected to low-illumination-intensity stress culture; in the dark period, the coral is placed in seawater without menthol to be cultured. According to the technical method for completely removing algae from the coral, based on the chemical induction effect of menthol on the coral-zooxanthellae symbiont, it can be guaranteed that zooxanthellae are rapidly and thoroughly discharged, the life vitality of the coral is kept, and the method is efficient, rapid, stable and free of pollution. Various experimental requirements such as subsequent coral host research and specific zooxanthellae colonization can be fully met, and the problems that a traditional thermal whitening method for inducing coral to discharge symbiotic algae is unstable, and coral host death is easily caused are solved.

Description

Technical Field

[0001] The invention relates to the technical field of coral breeding, and in particular to a method for coral algae removal based on menthol exposure. Background Art

[0002] The coral reef ecosystem is the "tropical rainforest" in the ocean. Its area does not even reach 0.1% of the ocean area, but it maintains the survival of more than 25% of the world's marine life. In recent years, coral bleaching has become one of the most serious ecological crises facing the global marine ecosystem. Coral bleaching is essentially due to the breakdown of the mutualistic symbiotic relationship between the coral host and the symbiotic algae (Symbiodiniaceae). When the seawater temperature continues to exceed the seasonal average by 1-2°C, the coral will expel the symbiotic zooxanthellae. Coral bleaching not only means the loss of biodiversity, but also indicates deep crises such as damage to the marine carbon pump mechanism and disorder of biogeochemical cycles. Therefore, it is of great significance to carry out systematic research on the stress resistance of corals under environmental changes and to breed highly stress-resistant super corals for the protection and restoration of coral reef ecosystems in the future.

[0003] If you want to conduct targeted research and screen for highly stress-resistant corals, you can colonize highly stress-resistant zooxanthellae in the corals, which requires the corals' original symbiotic algae to be removed. Currently, physical high-temperature stimulation is usually used to induce corals to expel symbiotic algae, but this method is not efficient in removing algae, and it takes a long time and has poor coral host stability. Therefore, a chemical algae removal method that can quickly and thoroughly remove coral algae is urgently needed to be developed. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a method for coral de-algaeing based on menthol exposure, so as to solve the problems of low de-algaeing efficiency, long time consumption and poor coral host stability of existing coral de-algaeing treatment methods.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: A method for coral algae removal based on menthol exposure, characterized by comprising the following steps: The corals are tamed in cycles of light and dark cycles to complete the algae removal; During the photoperiod, corals were placed in seawater containing menthol for low light intensity stress culture; During the dark cycle, corals were cultured in seawater without menthol.

[0006] The beneficial effects of the present invention are as follows: the present invention provides a method for completely removing algae from corals, which is efficient, rapid and stable, and can ensure rapid and thorough excretion of zooxanthellae and maintain the vitality of corals through the chemical induction of menthol on coral-zooxanthellae symbionts, and can fully meet various experimental requirements such as subsequent coral host research and colonization of specific zooxanthellae.

[0007] Furthermore, the coral is a Staghorn Pocillopora.

[0008] Furthermore, in each cycle, the light period was 6-12 h, and the dark period was 12-18 h.

[0009] Preferably, the light period is 8 h and the dark period is 16 h in each cycle.

[0010] Furthermore, the cycle domestication period is 4-5 days.

[0011] Preferably, the cycle acclimation period is 4 days.

[0012] Furthermore, the concentration of menthol during the photoperiod is 0.2-0.5 mmol / L.

[0013] Preferably, the concentration of menthol during the photoperiod is 0.38 mmol / L.

[0014] The beneficial effect of adopting the above further technical scheme is that the present invention ensures the stable effect of completely removing algae and bleaching the Acropora cup coral by adjusting the concentration of menthol addition, and can also effectively maintain the vitality of the coral, without affecting the subsequent re-colonization of highly stress-resistant zooxanthellae and the screening and cultivation of super stress-resistant corals.

[0015] Furthermore, the low light intensity during the photoperiod was 100-150 μmol photons / m 2 / s.

[0016] Preferably, the low light intensity in the photoperiod is 120 μmol photons / m 2 / s.

[0017] Furthermore, the corals were fed brine shrimp during the dark cycle.

[0018] Furthermore, the corals that have completed the algae removal are placed in seawater without menthol for recovery culture for 10-14 days, during which time they are fed with brine shrimp.

[0019] The beneficial effect of adopting the above further technical solution is that the present invention restores and cultivates the corals after bleaching and algae removal, and feeds a large number of brine shrimps, so that the corals can be heterotrophic instead of autotrophic, thereby maintaining the health of the coral host.

[0020] The above-mentioned method for coral algae removal based on menthol exposure is applied in breeding highly stress-resistant corals.

[0021] The present invention has the following beneficial effects: (1) The present invention provides a technical method for completely removing algae from corals. The method is efficient, rapid and stable, and can fully meet various experimental requirements such as subsequent coral host research and colonization of specific zooxanthellae. The traditional thermal bleaching method is relatively unstable in inducing corals to expel symbiotic algae, which can easily cause the death of the coral host. Based on the chemical induction effect of menthol on the coral-zooxanthellae symbiosis, the present invention can not only ensure the rapid and thorough expulsion of zooxanthellae, but also maintain the vitality of the coral. On this basis, the present invention ensures the stable effect of completely removing algae and bleaching the Acropora cup coral by adjusting the optimal menthol addition concentration.

[0022] (2) The present invention is specifically designed to target the characteristics of Acropora hornensis, which is widely distributed in the South my country Sea. It is an important technical support for the selection and breeding of Acropora hornensis with high stress resistance, and can provide valuable resources for the protection and restoration of the coral reef ecosystem in the South my country Sea. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The effect diagram of the algae removal treatment of Example 1 and Comparative Example 1-2, wherein a is Comparative Example 1, b is Comparative Example 2, and c is Example 1; Figure 2 These are microscopic observation pictures of the polyp of Acropora hornba before and after algae removal in Example 1, wherein a is before algae removal treatment, and b is after algae removal treatment. DETAILED DESCRIPTION

[0024] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0025] Embodiment 1: A method for coral algae removal based on menthol exposure, comprising the following steps: (1) Taking Acropora hornba as the research object, the coral colony was divided into 40 3×3 cm 2 The small strains of about 100 strains were first placed in a fresh filtered seawater culture tank for adaptive cultivation.

[0026] (2) Prepare a 1 mol / L menthol stock solution and add menthol to a fresh filtered seawater culture tank without corals to make the menthol concentration in the seawater 0.38 mmol / L. Adjust the light intensity in the culture tank to 120 μmolphotons / m2 / s, as a photoperiod culture tank.

[0027] (3) Place the culture tank filled with normal fresh filtered seawater in a dark environment as a dark cycle culture tank.

[0028] (4) The coral colony after adaptive cultivation in step (1) is placed in a light cycle culture tank at 9:00 every day, and transferred to a dark cycle culture tank at 17:00 every day. This treatment is continued for 4 consecutive days to complete bleaching and algae removal. A small amount of brine shrimp is fed during the dark cycle culture.

[0029] (5) After the bleaching and algae removal in step (4), the coral colony is placed in fresh filtered seawater for further cultivation for 12 days and fed with brine shrimp every day.

[0030] Embodiment 2: A method for coral algae removal based on menthol exposure, comprising the following steps: (1) Taking Acropora hornba as the research object, the coral colony was divided into 40 3×3 cm 2 The small strains of about 100 strains were first placed in a fresh filtered seawater culture tank for adaptive cultivation.

[0031] (2) Prepare a 1 mol / L menthol stock solution and add menthol to a fresh filtered seawater culture tank without corals to make the menthol concentration in the seawater 0.25 mmol / L. Adjust the light intensity in the culture tank to 120 μmolphotons / m 2 / s, as a photoperiod culture tank.

[0032] (3) Place the culture tank filled with normal fresh filtered seawater in a dark environment as a dark cycle culture tank.

[0033] (4) The coral colony after adaptive cultivation in step (1) is placed in a light cycle culture tank at 9:00 every day, and transferred to a dark cycle culture tank at 21:00 every day. This treatment is continued for 5 consecutive days to complete bleaching and algae removal. A small amount of brine shrimp is fed during the dark cycle culture.

[0034] (5) After the bleaching and algae removal in step (4), the coral colony is placed in fresh filtered seawater for further cultivation for 12 days and fed with brine shrimp every day.

[0035] Embodiment 3: A method for coral algae removal based on menthol exposure, comprising the following steps: (1) Taking Acropora hornba as the research object, the coral colony was divided into 40 3×3 cm 2 The small strains of about 100 strains were first placed in a fresh filtered seawater culture tank for adaptive cultivation.

[0036] (2) Prepare a 1 mol / L menthol stock solution and add menthol to a fresh filtered seawater culture tank without corals to make the menthol concentration in the seawater 0.45 mmol / L. Adjust the light intensity in the culture tank to 120 μmolphotons / m 2 / s, as a photoperiod culture tank.

[0037] (3) Place the culture tank filled with normal fresh filtered seawater in a dark environment as a dark cycle culture tank.

[0038] (4) The coral colony after adaptive cultivation in step (1) is placed in a light cycle culture tank at 10:00 every day, and transferred to a dark cycle culture tank at 16:00 every day. This treatment is continued for 5 consecutive days to complete bleaching and algae removal. A small amount of brine shrimp is fed during the dark cycle culture.

[0039] (5) After the bleaching and algae removal in step (4), the coral colony is placed in fresh filtered seawater for further cultivation for 12 days and fed with brine shrimp every day.

[0040] Comparative Example 1: A method for removing algae from corals, comprising the following steps: (1) Taking Acropora hornba as the research object, the coral colony was divided into 40 3×3 cm 2 The small strains of about 100 strains were first placed in a fresh filtered seawater culture tank for adaptive cultivation.

[0041] (2) Place the culture tank filled with normal fresh filtered seawater under a light intensity of 120 μmol photons / m 2 / s culture environment as a photoperiod culture tank.

[0042] (3) Place the culture tank filled with normal fresh filtered seawater in a dark environment as a dark cycle culture tank.

[0043] (4) The coral colony after adaptive cultivation in step (1) is placed in a light cycle culture tank at 9:00 every day, and transferred to a dark cycle culture tank at 17:00 every day. This treatment is continued for 4 consecutive days to complete bleaching and algae removal. A small amount of brine shrimp is fed during the dark cycle culture.

[0044] Comparative Example 2: A method for coral algae removal based on menthol exposure, comprising the following steps: (1) Taking Acropora hornba as the research object, the coral colony was divided into 40 3×3 cm 2 The small strains of about 100 strains were first placed in a fresh filtered seawater culture tank for adaptive cultivation.

[0045] (2) Prepare a 1 mol / L menthol stock solution and add menthol to a fresh filtered seawater culture tank without corals to make the menthol concentration in the seawater 0.13 mmol / L. Adjust the light intensity in the culture tank to 120 μmolphotons / m 2 / s, as a photoperiod culture tank.

[0046] (3) Place the culture tank filled with normal fresh filtered seawater in a dark environment as a dark cycle culture tank.

[0047] (4) The coral colony after adaptive cultivation in step (1) is placed in a light cycle culture tank at 9:00 every day, and transferred to a dark cycle culture tank at 17:00 every day. This treatment is continued for 4 consecutive days to complete bleaching and algae removal. A small amount of brine shrimp is fed during the dark cycle culture.

[0048] (5) After the bleaching and algae removal in step (4), the coral colony is placed in fresh filtered seawater for further cultivation for 12 days and fed with brine shrimp every day.

[0049] Test example: The corals treated in step (4) of Example 1 and Comparative Example 1-2 were observed and compared under microscopic observation. Figure 1 and Figure 2 shown.

[0050] Figure 1 It shows that the density of symbiotic algae in the coral tissue of Comparative Example 1 without the addition of menthol is very high and almost no treatment is achieved; in the experimental group of Comparative Example 2 in which 0.13 mmol / L menthol is added, due to the relatively low concentration of menthol, although the symbiotic algae in the coral tissue are partially removed, there are still obvious residual algae, and the symbiotic algae in the coral tissue are not completely removed; and in the experimental group treated with 0.38 mol / L menthol in Example 1 of the present application, the coral tissue has been completely bleached, and the algae removal is successfully completed, while the coral tissue still maintains a high vitality.

[0051] according to Figure 2 It can be seen that the polyps of Acropora hornii before the algae removal treatment were full of symbiotic algae, while the polyps of the corals after the algae removal treatment in Example 1 were completely free of symbiotic algae.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for coral algae removal based on menthol exposure, characterized in that: The following steps are involved: The corals are tamed in cycles of light and dark cycles to complete the algae removal; During the photoperiod, corals were placed in seawater containing menthol for low light intensity stress culture; During the dark cycle, corals were cultured in seawater without menthol.

2. The method for coral algae removal based on menthol exposure according to claim 1, characterized in that: The coral is a Staghorn coral.

3. The method for coral algae removal based on menthol exposure according to claim 1, characterized in that: In each cycle, the light period was 8-12 h and the dark period was 12-16 h.

4. The method for coral algae removal based on menthol exposure according to claim 1, characterized in that: The cycle training time is 4-5 days.

5. The method for coral algae removal based on menthol exposure according to claim 1, characterized in that: The concentration of menthol in the photoperiod is 0.2-0.5 mmol / L.

6. The method for coral algae removal based on menthol exposure according to claim 1, characterized in that: The low light intensity in the photoperiod is 100-150 μmol photons / m 2 / s.

7. The method for coral algae removal based on menthol exposure according to claim 1, characterized in that: Feed corals with brine shrimp during the dark cycle.

8. The method for coral algae removal based on menthol exposure according to claim 1, characterized in that: After the algae are removed, the corals are placed in seawater without menthol for recovery and cultivation for 10-14 days, during which time they are fed with brine shrimp.

9. Use of the method for coral algae removal based on menthol exposure according to any one of claims 1 to 8 in breeding highly stress-resistant corals.

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