Our lab time at PSN again. This time the experiments were about:
1) Cold fish
2) Water quality
After learning that we were to do an experiment with fishes, I initially didn't want to participate, but the PSN facilitator said that it wouldn't hurt the fish, and proceeded to get 2 fishes in 2 containers for my boys.
1) Cold fish
Purpose: To determine if temperature affects the movement of a fish's operculum and mouth
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| We were given this drawing of parts of a fish |
We were asked to count how many times per minute the fish opens and closes its mouth and operculum at different temperatures. Having learnt Science in Bahasa Malaysia when I was in school, I hadn't heard of the term operculum before and now just learned that it meant "penutup insang". The first count was the current temperature of the water in the fish tank. Then we had to repeat the counting for 2 more times and get an average.
The second was in icy water. Put a block of ice into the jar to get the water to make it colder. Then we had to count again, and repeat for 2 more times. After the first round of counting, I decided to abandon this project and returned our fishes to the facilitator. I thought it was too cruel to the fish. Repeating it 3 times per temperature was too long and too stressful for the fish, I thought. I was also horrified to see a little boy taking the thermometer and stirring his fish in the jar, just like stirring a bowl of soup.
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| The block of ice reduced the temperature to 18 celcius |
Everyone was supposed to do a third round, and put in more ice until the temperature reads 10 celcius, but by then, the children were restless and the moms decided to stop, and return their fishes. We had learnt enough that when the fish is in warmer water, it opens and closes it's mouth and operculum more frequently, compared to being in cold, icy water. We learnt that animals conserve energy when in cold environment. Their body loses hear (and thus energy) when the temperature is colder, thus, their body movement slows down.
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| The facilitator calls this the 'ICU' by the facilitator. Fish in the icy water have to be left in their jar and the jar put inside the water in the large fish tank in order to acclimatise back to the normal tank water temperature. |
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| Finally, all the fishes recuperated and lived to see another day |
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| This rubber fish looks very real |
2) Water quality
We also did another experiment to test the water quality of pond water versus tap water.
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| Using a pipette to drop water into a small test tube |
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| We used a freshwater master test kit to test for pH, Ammonia and Nitrite in the pond water and tap water |
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| Indicator cards |
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| Dropping several drops of the solution into the tube of pond water and tap water. |
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| The solution changed colour and turned blue indicating the pH of the water. Compare the water colour against the colour and number on the card |
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| Testing for ammonia - the water turned light yellow |
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