Friday, November 16, 2012

Wednesday, November 14, 2012

Alevins on the move (almost)

In this short video, you can see the alevins as they move around in a petri dish.  They are not quite free swimming yet, but they are getting bigger and moving more vigorously every day.

Alevins are growing!

In this photo, a few of our alevins are in a petri dish with a penny on a paper towel underneath to give a sense of their current size.

Testing the Water in the Trout Tank

In middle school we take care of our trouts by doing four tests to see if the fish tank water is clean and
they are living in a safe environment. The tests are for pH, ammonia, nitrite, and nitrate levels.

The acidity level of a tank is measured by doing a pH test.  A pH level of 7.0 is neutral.  If the reading is higher than that, the tank is alkaline.  If the pH is lower, the water is acidic.  To test for pH, we fill a test tube with 5 mL of water and add three drops of test solution.  Then we compare it to the color chart.  If the pH is too high or too low in the tank, we will add chemicals that help adjust it to the right level.  

Another important test  is for ammonia levels.  Ammonia levels can be too high because of fish waste and decaying uneaten food.  The level should be 8 ppm or less.  To test for ammonia, we fill a test tube to 5 mL, then add two different kinds of testing solution.  After we shake it, we have to wait 5 minutes for the color to develop.  Then we compare it to a color chart.   If there is too much ammonia, we can do a partial water change or add special materials to the filter that will take out the ammonia.  

We also test for nitrites in the tank.   There are beneficial bacteria in the tank, but they can also make toxic nitrites if the ammonia level is too high.  Nitrites interfere with the trouts’ respiration.  To do the test we fill a test tube up to 5ml.  Then we add 5 drops of testing solution, shake for 5 seconds, and then let it sit for 5 minutes.  The nitrite level should be 0 parts per million (ppm).  If it is too high, we can add a special material that will remove it from the water.  We can also add beneficial bacteria and aquarium salt.  

We do a nitrate test to see if the tank is unhealthy from a build up of fish waste. If there is too much nitrate the tank will cause the fish to get sick and die.  When we do the test, we fill a test tube with 5 mL of water from the tank.  Then we add two different kinds of testing solution and shake for at least 30 seconds.  We compare our results to a color chart to see what the nitrate level is.  A nitrate level of 40 parts per million (ppm)  or less is healthiest.

~by Antek, Ellie, Lydia and Gavin

Sunday, November 4, 2012

Here's a short video of the remaining 65 alevins swimming.
Went into school today to take care of the animals and I'm happy to report that there are 65 little trout still alive even with the power out all week.  Survival of the fittest, indeed!

Wednesday, October 24, 2012

Yesterday, we had our first eggs hatch!  The newly hatched eggs are called alevins.  They look like this:

The sac on the bottom of the newborn baby trout is its egg, which it is still using for nutrition.

Middle school students viewed one of the alevins under our new digital microscope, which is able to take pictures and videos.  Below, see a closeup picture, taken by 8th grader Hunter, of the alevin's spine and another of its egg sac:

                                                                            Egg Sac

It's so exciting to have new life in our classroom!  Feel free to come down and see the new babies.