Handout 2: Blackworm Lab

Lab Procedures:

  • treatment solutions

If the treatment solutions are not already prepared, create the dilutions in a beaker using the appropriate graduated cylinder to measure the amount of alcohol.

  • label dishes

Each treatment should have a dish to keep the worms in a healthy setting (water only) and a dish to put the treatment solution in. Label each dish according to what it will have in it. Label them so that you can tell while you are performing the experiment.

  • fill dishes

Fill each dish with the solution indicated by the labels you have put on them.

  • make initial observations

Place 10-20 worms into each of the water dishes and let them settle for 2-3 minutes. During this time, make observations and take notes of the worms’ behavior in a healthy setting. Do your best not to disturb the worms, but gentle probing may encourage them to be more active.

  • transfer worms

Move worms from each water dish into the paired treatment dish. Do this carefully, carrying as little liquid from the initial dish into the new dish. (Think about why you might not want to move too much liquid.)

  • make observations

Using the “exposure” sheet provided (Handout 3), take observations (both the level of activity and notes about other observations) at 0, 3, 6, and 10 minutes. You may look at behavior, again, without disturbing the worms and using gentle probing. Be careful about too much probing, as you might miss some interesting effects of the toxin.

  • replace worms into water dishes

Once you have completed your observations, replace the worms into their original water dishes for “recovery” from each treatment. Again, be careful to move as little liquid from the treatment dish into the water dish.

  • make observations

Using the “recovery” sheet provided (Handout 4), make observations as to the behavior of the worms once they are placed into their water dishes. Do they revert to the original behavior? Do you think they will? Why or why not?

  • clean up

Place all the liquid you can into an available beaker. Place the worms into another beaker. Throw away weigh dishes once empty. Clean off spoons or pipettes and the graduated cylinder and return it to the place your instructor designates. Clean off the table.

  • reflection

Use the notes you took during your experiment to complete your “Reflection” (Handouts 5 & 6). Base your analysis on the details from your observations.