Lumbriculus variegatus Figure 2 Lumbriculus variegatus Pulse Rate of Blackworms Pulse Rate in Lumbriculus variegatus when placed in a stimulant and plain water. By, Malia Rogers and Jacob Weller Abstract: The California Blackworm’s pulse rate was observed in a microscope. Two worms were compared. One worm was placed in a stimulant and the other worm was placed in plain water. The pulse rate was counted for one minute. This trial was repeated 5 times for each worm. The results showed that the worm in the plain water had a faster pulse rate than the worm in the stimulant. Methodology: Procedure: Place some worms in water with a stimulant. Place some worms in plain water. Use 3 layers of tape to cover the slide and cut out a small rectangle. Place a worm from the plain water in the slide with a little of the water. Count the number of pulses using a microscope for 1 minute. Repeat 5 times. Put that worm back and place a worm from the stimulant on the slide. Count the pulse for 1 minute. Repeat 5 trials. Compare the average results. Materials: Microscope, slide, cover, and tape. At least 2 California Blackworms. Water with stimulant. Plain water. Statistical Tests: 5 trials for each worm. Count the number of pulses in 1 minute. After five trials average the results for each worm to compare. Discussion: The data does not support the hypothesis. The significance is that in humans, stimulants will usually increase pulse rate, however, in worms it does not affect them, if anything it slows the pulse down. This must mean that there is a difference in the way the water enters the body or a difference in the way the system absorbs the water. Also, if the stimulant wasn’t strong enough, or diluted, then it could affect the effect of the stimulant. Finding if depressants also have little effect or the opposite effect will show that the water is not being absorbed into the blood stream the same way it is absorbed in humans or that Blackworm bodies have a different reaction to chemicals than humans. Introduction: Will a worm placed in a stimulant have a change in pulse rate? Stimulants in people increase energy and can cause many physical reactions. They enhance the activity of the central and peripheral nervous system. They can increase heart rate, blood pressure, and alertness. We inferred that the same effect would take place in California Blackworms. We formed the hypothesis that, if a worm is placed in a stimulant, then its pulse rate will increase more than a worm placed in plain water.   Figure 1 Trial Number Stimulant Worm Pulse/Minute Plain Water Worm Pulse/Minute 1 18 20 2 16 3 4 12 5 14 22 Median 19 Mean Results: The average pulse rate for the worm with the stimulant was actually 2 pulses/minute less than the pulse rate of the worm in plain water. In figure 1 and 2, the plain water worm is 20 and the stimulant worm is 18. The results fluctuated and individual trials do vary. But overall, the pulse rate of the plain water worm was higher.