Biomphalaria glabrata is a freshwater snail that originates from Central and South America. The NMRI strain of Biomphalaria glabrata exhibits albinism. The snails’ albinism makes them transparent, which provides the opportunity to observe their circulatory anatomy and physiology. They lay eggs in masses, with 2-30 eggs per mass. The eggs go through several developmental stages. First, they are fertilized. Each egg contains a single embryo, which then begins to grow. Each embryo measures approximately 100 µm in diameter when it first begins to grow (Magalhães et al. 2003). The embryo reaches the blastula stage between 10 to 23 hours after the eggs are laid (Mitasato et al. 2012). From here, the snails grow rapidly, and by the third day have
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The snails were fed lettuce ad libitum. Egg masses containing multiple embryos were laid on polystyrene foam pieces, which were collected between 24-48 hours of exposure, and then moved into a separate incubator. Control flasks of pond water were kept and dechlorinated pond water was added whenever the petri dishes with the embryos ran low on water. The embryos were aged for four days to allow the heart to develop.
Octopamine was ordered from Sigma-Aldrich (St. Louis, MO, USA) in a solid form and then was diluted to a 1mM solution for storage. When the embryos were ready to be tested, the solution was removed from the refrigerator and diluted to twice the needed concentration. The concentrations tested were 100 µM, 50 µM and 25 µM; they were tested on separate days. The experimental design accounted for one treatment group and one control group for each dilution of octopamine solution. A 12-cell well was filled with 0.5mL of pond water. An egg mass was then placed in one of the cells and given a one minute acclimation period. Then the embryo was placed under a Nikon dissecting microscope connected to a Sony video camera. After that, a three-minute basal video recording was done using the camera. Once the basal recording was completed the treatment solution (either pond water or octopamine) was added using a micropipette for the experimental trial. Then a three-minute …show more content…
Each three-minute video of both basal and experimental recordings was analyzed Within each egg mass, the heart rate of 3 embryos were accounted for and averaged for the respective egg mass. Embryos were chosen based off of how clearly their heart rates could be seen. Hand tally counters were used to count how many heartbeats each embryo had.
A student t-test was used to determine the significance of the data when comparing the effects of the octopamine to that of the controls. The data was analyzed using the “Microsoft Excel 2010” spreadsheet software.
Results:
The main goal of this study was to observe the effects of octopamine on the heart rate of Biomphalaria glabrata embryos. After observing the data, only one statistically significant difference between a control and experimental trial was found. This was the difference between the 50-µM concentration of octopamine and its control. For the 50-µM trials the mean BPM was 180.6 (± 7.6), while the control was 140.5 (± 3.5). When comparing the two, the p value was 0.001. For the 100-µM trials the mean BPM was 185.7 (± 4.2), while the control was 173.2 (± 17.1). When comparing the two, the p value was
The snails were fed lettuce ad libitum. Egg masses containing multiple embryos were laid on polystyrene foam pieces, which were collected between 24-48 hours of exposure, and then moved into a separate incubator. Control flasks of pond water were kept and dechlorinated pond water was added whenever the petri dishes with the embryos ran low on water. The embryos were aged for four days to allow the heart to develop.
Octopamine was ordered from Sigma-Aldrich (St. Louis, MO, USA) in a solid form and then was diluted to a 1mM solution for storage. When the embryos were ready to be tested, the solution was removed from the refrigerator and diluted to twice the needed concentration. The concentrations tested were 100 µM, 50 µM and 25 µM; they were tested on separate days. The experimental design accounted for one treatment group and one control group for each dilution of octopamine solution. A 12-cell well was filled with 0.5mL of pond water. An egg mass was then placed in one of the cells and given a one minute acclimation period. Then the embryo was placed under a Nikon dissecting microscope connected to a Sony video camera. After that, a three-minute basal video recording was done using the camera. Once the basal recording was completed the treatment solution (either pond water or octopamine) was added using a micropipette for the experimental trial. Then a three-minute …show more content…
Each three-minute video of both basal and experimental recordings was analyzed Within each egg mass, the heart rate of 3 embryos were accounted for and averaged for the respective egg mass. Embryos were chosen based off of how clearly their heart rates could be seen. Hand tally counters were used to count how many heartbeats each embryo had.
A student t-test was used to determine the significance of the data when comparing the effects of the octopamine to that of the controls. The data was analyzed using the “Microsoft Excel 2010” spreadsheet software.
Results:
The main goal of this study was to observe the effects of octopamine on the heart rate of Biomphalaria glabrata embryos. After observing the data, only one statistically significant difference between a control and experimental trial was found. This was the difference between the 50-µM concentration of octopamine and its control. For the 50-µM trials the mean BPM was 180.6 (± 7.6), while the control was 140.5 (± 3.5). When comparing the two, the p value was 0.001. For the 100-µM trials the mean BPM was 185.7 (± 4.2), while the control was 173.2 (± 17.1). When comparing the two, the p value was