Eliminating coral-eating nudibranchs with potassium permanganate.

 

An Effective Solution

Procedures

Preparing Solutions

1. Prepared a 10,000mg/L (10g/L) stock solution by adding 5.00g KMnO₄ to a 500mL volumetric flask and filling to volume mark with distilled water.

2. Diluted 0.50mL stock solution to 500mL with synthetic seawater to produce a solution of 10mg/L.

3. Repeated step 2 with stock solution volumes of 1.25mL, 2.50mL, 3.75mL, 5.00mL, and 7.50mL to produce solutions with concentrations of 25mg/L, 50mg/L, 75mg/L, 100mg/L, and 150mg/L, respectively.

4. Stored solutions in stoppered Erlenmeyer flasks.

 

Nudibranch Tests

1. Transferred 80mL of synthetic seawater from holding tank to a petri dish.

2. Transferred 10 nudibranchs from a coral colony to the petri dish.

3. Repeated steps 1 and 2, substituting KMnO₄ solutions for synthetic seawater.

4. Observed each test group for 90 minutes from time of initial immersion. Observed each test group under a microscope at regular intervals.

5. Recorded observations and discarded all solutions and nudibranchs from test groups.

 

Egg Tests

1. Transferred 80mL of synthetic seawater from holding tank to a petri dish.

2. Transferred several nudibranch egg masses from a coral colony to the petri dish.

3. Repeated steps 1 and 2, substituting KMnO₄ solutions for synthetic seawater.

4. Observed each test group for 90 minutes from time of initial immersion. Observed each group under a microscope at varying intervals.

5. After a period of 90 minutes, egg masses from each test group were removed from immersion, rinsed in clean holding tank seawater, and placed in separate test tubes suspended in the holding tank. Solutions were then discarded.

6. Eggs were observed under a microscope at 48 hour intervals to determine vitality.

7. After the eggs in each test group were confirmed to be either viable or non-viable, the eggs and water in the test tubes were discarded.

 

 

 

 

 

 

 

 

 

 

 

 

Coral Tests

1. Transferred 500mL of synthetic seawater to a 1L beaker.

2. Placed an infested colony of Montipora capricornis into beaker.

3. Repeated steps 1 and 2 using each concentration level of KMnO₄.

4. Removed corals after 90 minutes of immersion.

5. Rinsed coral colonies in clean synthetic seawater and returned to holding system.

6. Observed at 24-hour intervals for 48 hours.

7. Immersed samples of M. digitata, M. capricornis, M. confusa, M. capitata, and one unidentified Montipora species in 500mL of 50mg/L KMnO₄ solution for 90 minutes.

8. Rinsed coral samples and returned to holding tank. Observed for 48 hours.

Nudibranch and Egg Tests