Final Presentation: PowerPoint File
Post on 12-Dec-2014
- 1. Dragonflies Feeding on Amphipods; Size Does Matter Linda White, Kenny Danner, Shane Murnan, Craig Henson, and Lori Espieg Research Scientist: John White
2. Introducingour study subject
- We will be studying theHylellaamphipod.
3. Introducingour prey
- Dragonfly nymph
4. Step 1
- We added 400 mL of non-chlorinated well water to fifteen individual sandwich sized 900 mL quart serving containers .
5. Step 2
- We placed four four inch segments of ambulia plastic aquarium plants.
6. Step 3
- All of the containers were left overnight to reach ambient temperature and oxygenate the water.
7. Step 4
- Dragonfly larvae were separated into individual plastic beverage containers overnight to rest.Dragonfly larvae were not fed to ensure that each dragonfly had an appetite.
8. Step 5
- We separated all of the amphipods into four categories; small, medium, large, and females with broods. The females with broods were placed in a separate container.
9. Step 6
- We placed eight small, eight medium, and eight large amphipods into each container.
10. Step 7
- After allowing the amphipods to rest in the containers, we placed one dragonfly larvae in each container.
11. Step 8
- After allowing nature to take its course, we returned to examine our results.
12. 13. Step 9
- The dragonfly larvae had a bigger appetite than expected.We found no amphipods.All of our test subjects had been consumed.
14. Step 10
- We conducted our experiment a second time using eight of each size amphipod in each arena.We placed the females with broods in a separate container.
15. Step 11
- Our dragonfly larvae were left in the arenas for twelve hours.After twelve hours the dragonfly larvae were separated from the amphipods.
16. Step 12
- We placed the remaining amphipods and dragonfly larvae in a vial with ethanol solution killing juice to preserve them for measuring.
17. Step 13
- We sorted the amphipods based on size remaining on Petri dishes for each arena.
18. Step 14
- Using a microscope, we measured the head length of each of the remaining amphipods.
- We measured the head width of each dragonfly larvae.
19. Step 15
- All of our data was entered into a spreadsheet so we could draw conclusions based on our data.
- We determined that the dragonfly larvae preferred the medium size amphipods to the small or large amphipods.
21. 22. Conclusions
- Through the analysis of our data, we determined that the dragonfly larvae prefer amphipods that are medium sized.
- Reasons for this could be the energy used to catch the amphipod in relation to the energy gained by consuming the amphipod.
23. Ideas for Future Study
- Comparing females with and without broods to males of the same size.
- Comparing females with and without broods.
- Increase the variation of dragonfly larvae size.
24. More Ideas for Future Study
- Painting black dots on males to determine if it increases visibility or attractiveness.
- Analyze energy content to determine if females with broods provide a higher energy return for dragonfly larvae.
- Introduce other predators to determine which size amphipod they prefer.
25. Potential Predators
- Toe Biters
26. Disclaimer 27.