Variegatus Vs Blackworm Essay

Introduction Lumbriculus variegatus, or blackworms, are part of the segmented worms called annelids. The body is organized into repeated segments. It has a closed circulatory system, similar to humans because the blood is contained within blood vessels. Two major blood vessels, the ventral and dorsal vessels, run straight from the head to the tail, and several vessels connect the two in the anterior segments. The dorsal blood vessel acts similar to the heart, pumping the blood through wavelike contractions of its muscular walls. Blackworms have bright, red blood because of the presence of a hemoglobin-like pigment, erythrocruorin, which transports oxygen. Because the body wall of the worm is transparent, the blackworm’s pulse is visible as the dorsal
We did not expect this at all. The pulse rate for the control treatment also increased, but this could have been due to the stress of moving the worms from dish to dish. The low and medium treatment increased, but the high treatment did not. These results could have been because of error on any of the treatments. Overall, our results did not support our hypothesis. This experiment actually proved our thinking wrong. Some factors that could have affected our results include the different sizes of the worms and inconsistencies in counting. The bigger the room, the more alcohol it would need to be affected like the smaller worms. Counting always has room for error because the person counting could have counted something he or she thought was a pulse but was really a movement. If our group had more time with the experiment, we would like to wait longer for the worms to get adjusted so they would not be as stressed. We would also like to see if the size really affects the pulse rate in alcohol or not. Because blackworms have a similar circulatory system, it would be interesting to see how one chemical affects humans compared to