Phylogenetics of Three Populations of the Tasmanian Giant Lobster (Astacopsis Gouldi)
The Tasmanian giant lobster, Astacopsis gouldi is an endangered species of crayfish isolated to the north and northwestern regions of Tasmania. Over the past ten years, Australia has been undergoing one of its most extensive attempts ever to help conserve its biodiversity. Using regions set up by IBRA (interim biogeographic regionalisation for Australia), the country is establishing a national reserve system to protect unique ecosystems. Aiding in the effort are molecular biologists who are now using systematics techniques to help assign conservation priorities to different regions within Australia. Using molecular clocks and sequencing techniques, the ancestry of a given gene can be traced and the amount of gene flow between populations or species can be estimated. This information can then be used to estimate the phylogenetic relationships between different populations or species, which can aid in conservation efforts. The goal of this study was to use 16S mtDNA sequence information to infer phylogenies between three physically isolated populations of A. gouldi. The 16S mtDNA gene is a mitochondrial gene that has been used before in phylogenetic studies of crayfish as well as other organisms (Meyer et aI, 1990; Crandall, 1998; Crandall et aI, 1999; Izeni et aI, 2000). After the 16s gene was sequenced in all three populations of crayfish, three different but comparable phylogenetic trees were derived using PAUP*4.0b4 (Swofford,2000), a program designed to estimate the phylogenetic relationships among population or species groups. These trees all showed that while the three populations of crayfish examined were closely related to each other genetically, there was a healthy amount of variation at the genetic level as well. This information, as well as other sequence information gathered in this study, was then used to make some simple suggestions that may aid in the conservation efforts of A. gouldi in Tasmania.