Morphology of Dragonflies

Lab Section 1 Wednesday 1:10-4:00 M. Moore Zoology Lab #1 Morphology of Dragonflies In analyzing the morphology of dragonflies by looking at two different time periods and the water levels, data was found to illustrate that body size might be directly influenced by water levels. By looking at the dragonfly species Sympetrum vincinum during the 2001 drought and 2008 normal rainfall, the data showed that there was no statistical difference in abdomen depth (p value 0. 20741). There was a statistical difference in forewing length (p value 0. 006), hindwing area (p value 0. 000164) and thorax depth (p value 0. 0001). The means provided from the different species showed that there was a small difference from 2001 to 2008 and that the 2008 data was smaller with the normal amount of rainfall opposed to the 2001 draught.The Mean for 2001 of the Forewing length (23. 30mm), Hindwing area (169. 88mm2), thorax depth (6. 04mm), abdomen length (21. 08mm), were larger than 2008. The 2008 means are as follows, Forewing Length (22. 06mm), Hindwing Area (148. 61mm2), Thorax Depth (5. 25mm) and Abdomen Length (20. 0mm). In the study â€Å"Fitness and body size in mature odonates† it was found that body size has an important role in the fitness of dragonflies and is directly related to their ability to reproduce and survive (Sokolovska, Rowe, and Johansson 2000). Through this study it was found that there was no statistical difference in the abdomen depth from 2001 and 2008 with varying water levels. This suggests that the dragonflies did not change their abdomen size because that particular size was the one that best aided their fitness, not relying on water levels.Egg Laying in Petrels: Successful versus Failed Eggs In the comparison of the successful eggs and the failed eggs, there was a statistical difference between them concerning the egg’s length, breadth and mass. This leads to idea that the failed eggs were not cared for as well as the successful eggs had be en. For the comparison of the successful versus the failed eggs, the egg length (p value 0. 01849), egg breadth (p value 0. 00057) and the egg mass (p value 0. 00057). In the study of â€Å"Leach’s Storm- Petrel done by Huntington et al. n 1996, they found that there may be various reasons why there are unsuccessful egg hatching with these birds. In the data analysis of the successful versus the failed eggs the reasons that there is a statistical difference between them may be because of nesting site, incubation time, or size of parental birds (Huntington et al. 1996). There are many factors to contribute to the reasons why there is a statistical difference between the sizes of the successful versus failed eggs. This data proves that there is a significant difference between the egg sizes and this will lead to further studies to gain more information.Egg Laying in Guillemots: Inter- Year Effects The data found from the analysis of measuring the length and breadth of eggs fro m Guillemonts to see when the birds had better reproduction ability from the first year of their breeding in comparison to their second or third year. The data illustrated a statistical difference between the egg length and breadth from the first year to the second or third year. The birds produced larger eggs in their first year of breeding in comparison to their second or third year breeding.The length comparison between first year and second or third year (p value 0. 00036) and the breadth comparison was (p value 0. 019112), which both exhibit a significant statistical difference. The egg size and shape varies on many different factors including the environment, the age of the female and when the eggs are laid (Butler and Buckley 2002). This analysis proves the point that egg size is affected by the age of the female and that the first breeding season of the female produces the best eggs.Works Cited Butler, G. R. , Buckley, E. D. 2002. Black Guillemot. The Birds of North America, No. 675. Huntington, E. C. , Butler, G. R. , and Mauck A. R. 1996. Leach’s Storm- Petrel. The Birds of North America, No. 233. Sokolovska N. , Rowe L. , and Johansson F. 2000. Fitness and body size in mature odondates. Ecological Entomology, 25:239-248. Table 3. Wing Variable recorded for male Sympetrum vincinum at Lemon Stream in Franklin County (ME) in September 2001 and September 2008. Table 3. . Morphological variables recorded for male Sympetrum vincinum at Lemon Stream in Franklin County (ME) in September 2001 and September 2008. Table 6. Egg measurements collected on Great Island (Newfoundland, Canada) from nesting Leach’s Storm-petrels in 1983 (from Butler, unpublished data). Table 9. Black Guillemot egg measurements collected on Great Duck Island (Hancock County, Maine) from banded adults in their 1st and 2nd and 3rd breeding seasons 1991 and 1993 (Butler and Barkley 2002).