Introduction: Lumbriculus variegatus is a scientific name for an organism found in freshwater habitats throughout North America and Europe.. Common names.

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1 Introduction: Lumbriculus variegatus is a scientific name for an organism found in freshwater habitats throughout North America and Europe.. Common names for it include: blackworm, california blackworm, and mudworms. They live in microhabitats. Rotting logs immersed in water and the edges of ponds are among their favorite.The blackworm tail specializes in gas exchange between the air and their dorsal blood vessel.. Blackworms are an organism that reproduces asexually by fragmentation; the blackworm will break apart then grow a new body, head, or both. They also have a very thin exterior with translucent skin. All of these characteristics make experimenting on them very easy and educational. Hypothesis: If a blackworm is exposed to water with a stimulant in it than its pulse rate will be faster than a worm exposed to a worm in depressant water. Independent Variable was the stimulant that is added to the water Dependent Variable was the pulse rate Constants were the temperature they were kept at (4 degrees C) and the type of worm that were being tested. Materials: ●Microscope ●Blackworm ●Well slide Conclusion: After concluding our experiment on lumbriculus variegatus, the data does not support our hypothesis. We predicted that if our worm was exposed to a stimulant in water, than its pulse rate would’ve been faster than the worm that was in the water with a depressant. There were many limitations in the experiment like the inability to use the same exact worm or run more trials. These results were very unexpected because usually a stimulant will stimulate or increase the pulse rate while depressants slow down the pulse rate. Errors that could’ve happened are the wrong worms could’ve been grabbed before experimenting or pulse rates could’ve been missed while the worm was squirming under the microscope. Another thing that may have skewed the results, was if a worm that had already been tested was taken out of the community bowl then it may have already been agitated or tire from being previously worked with. With that being said, in the future it may be best to try the experiment with more time for trials and possibly get a smaller well slide to reduce the space that the worm has to move in. Results: The blackworm exposed to a stimulant had a lower pulse rate, average being 13.5 pulses/min but ranging from 10 to 16. The blackworm exposed to a depressant had an average pulse rate of 18.3 and ranged from 17 to 20. The blackworm was highly active after accumulated time under the microscope making each trial more of a challenge. Procedure: First we used a pipette to select a blackworm from the stimulant dish We then put the worm on a slide, drawing out water. We then put the cover slide on top to keep our worm in its well. After setting up this part of the experiment, and then the microscope, we continued with counting its pulse rate per minute. We did 10 trials, turning off the microscope’s light after each trial to prevent frying the worm and agitation. After our stimulant worm was tested, we put him back in its dish and did the whole process over with a worm from depressant water. The Effects of Stimulants on Blackworms Madeline Gibbs and Caitlin Malanowski Genesee Community College Bio 100, Albion High School References Drewes, C., (2004, September) Lumbriculus variegatus: A Biology Profile, Pbworks.com ●Pipette ● Timer