1 / 17

River Specific Shell Morphology of Emydura Turtles

Why research turtle shells?. The question,

mauli
Download Presentation

River Specific Shell Morphology of Emydura Turtles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. River Specific Shell Morphology of Emydura Turtles Jonathan J. Reinig: jjreinig@ucdavis.edu McNair Scholars Program Dr. H. Brad Shaffer Department of Evolution and Ecology University of California, Davis

    2. Why research turtle shells? The question, “What is a species?” has concerned scientists for centuries The reasons for classifying organisms into species is profound Knowing the amount of species that exist on our planet contributes to our basic understanding of life on earth In order to protect biodiversity on earth we need to protect as many species as possible If cryptic species exist, and are in danger, than we will not be able to protect them

    3. Emyduras: Emydura is a genus of moderate sized, “short necked” turtles that inhabit fresh water streams and rivers Emydura maquarii This genus of turtles belongs to the family Chelidae, which is distributed throughout Australasia, South America, and Africa (Cogger, 2000)

    4. Emydura Range: Emydura is native to eastern and northern Australia, and New Guinea (Cann, 1998) Note: this project was not concerned with specimens from New Guinea

    5. The Emydura dilemma: The number of species that exist within Emydura has been under debate for some time (Arthur and Adams, 1992) Cogger claims that the genus is composed of Five species (Cogger, 2000) Cann, however, believes that the genus contains at least ten species, with one species, Emydura maquarii, containing seven subspecies (Cann, 1998) This project used a technique known as Morphametrics to determine if river specific shell differences occur within the genus Emydura The long term goal of this project is to compliment genetic data to define definitive species boundaries within Emydura

    6. Morphametrics: Morphametrics is a technique used to discern minute morphological differences between organisms It uses computer software to place digital landmarks on pictures of a set of organisms The digital land marks are than analyzed via additional computer software

    7. Materials: Dr. H. Brad Shaffer has compiled genetic samples and a complete photo record of approximately 1,500 Emyduras This photo record consists of one photo of the carapace (the top shell) and one photo of the plastron (the bottom shell) for each of the 1,500 turtles Each photo was then digitally analyzed using TPS digital software

    8. Methods: carapace The carapace had 49 digital land marks placed on it These digital land marks where placed on each turtle in the same spots of the carapace, in the same order

    9. Methods: plastron The plastron received 16 digital land marks As with the carapace, the digital landmarks where placed in the same location and order for each plastron

    10. Analyzing the Data: Each of these landmarks represent a X and Y coordinate on a grid. A commercial software program known as JMP was then used to analyze the data collected from the TPS digitization's JMP was than used to test for statistical differences existing in the shell morphology of different populations inhabiting different rivers

    11. Results: Currently, I’m still conducting data collection on this project I hope to start to get results by late August Many curious problems arose while digitizing the turtle shells

    12. Unusable photos:

    13. Discussion: We hope to find river and/or geographical specific shell morphologies This would indicate that there is negligible gene flow between rivers If this predictions holds true, than information from this project will contribute to our understanding of the true species boundaries of Emydura The different shell types will help to define characteristics of each species

    14. Next steps (Future Studies): Next month I will be traveling to Brisbane, Australia gather more photos of Emyduras I will visit the Queensland museum, which houses some 700 Emyduras. These will be photographed and will greatly increase our sample size Dr. Shaffer will compare the shell morphology data with the corresponding genetic data to see if genetic clades exhibit unique shell morphology relative too each other

    15. Work Cited: Cann, John. Australian Freshwater Turtles. 1998. Beaumont Publishing Pte Ltd. Cogger, Harold G. Reptiles and Amphibians of Australia. 6th ed. 2000. New Holland Publishers (Australia) Pty Ltd Georges, Arthur. Adams, Mark. A Phylogeny for Australian Chelid Turtles Based on Allozyme Electrophoresis. 1992 Australian Journal of Zoology, 40, 453-76

    16. Acknowledgments: I would like to thank: Dr. Brad Shaffer, Everyone in the Shaffer lab, The McNair program, staff, and fellow scholars The Presidents Undergraduate Fellowship

    17. River Specific Shell Morphology of Emydura Turtles Jonathan J. Reinig; jjreinig@ucdavis.edu McNair Scholars Program Dr. H. Brad Shaffer Department of Evolution and Ecology University of California, Davis

More Related