An Ecological, Morphological and Molecular Investigation of Beddomeia Species (Gastropoda: Hydrobiidae) in Tasmania Karen Richards BScEd, Melbourne College of Advanced Education BAppSc (Hons), Deakin University A thesis submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy University of Tasmania September 2010 ii Declaration This thesis contains no material which has been accepted for the award of any other degree or diploma by the University or any other institution. To the best of my knowledge the thesis contains no material previously published or written by another person except where acknowledgement is made in the text. Karen Richards Date Statement of Authority of Access This thesis may be made available for loan and limited copying is permitted in accordance with the Copyright Act 1968. Karen Richards Date iii iv Abstract Narrow-range endemic species are thought to have naturally small distributions, limited by size, mobility, dispersal capabilities, specific habitat requirements and biogeographical boundaries. Many narrow range taxa are poorly reserved and most threatened freshwater invertebrate taxa in Tasmania, including the majority of Beddomeia species, fall into this category. Management of such taxa is reliant on informed ecological data which is not currently available for many freshwater invertebrates. To address the need for more detailed information on one such group of aquatic invertebrates, this study obtained spatial and ecological data for a number of Beddomeia species and identified habitat variables that together explained the snail distributions. A combination of geology, catchment size, forest type, flow and disturbance were identified as significant explanatory variables of Beddomeia presence within a river catchment. The distribution of some Beddomeia species is greater than previously predicted (at the catchment level), the Beddomeia spp. investigated were shown to occupy a wider number of streams than previously thought, suggesting that this is likely to be observed in other Beddomeia species. Detailed population structure data supported the previously held belief that Beddomeia spp. are long-lived and have low fecundity. Anthropogenic disturbance to streams, resulting from agricultural and forestry operations has previously been identified as a potential risk to aquatic invertebrates, particularly narrow-range endemics, but this has not, until now, been tested for Beddomeia species. The effects of cable- harvesting forestry disturbance on a high density Beddomeia sp. population were investigated. Population data indicated a recovery of population structure, if not abundance, within five years post-harvest, suggesting a higher level of tolerance to disturbance than had been previously anticipated. Sympatric associations between Hydrobiidae are not uncommon and were observed for Beddomeia spp. in many of the streams investigated. Several morphotypes from each of the two major study catchments, initially determined by shell measurements, were taxonomically described using a combination of external and internal characters that indicate a high level of intraspecific shell variation occurs, and failed to support the number of morphotypes identified using shell characters alone. The molecular taxonomic resolution within the genus Beddomeia was also explored, but the monophyly of the genus remains unresolved owing to the disparity of topologies recovered. v Results obtained from these studies are used to review the management of Beddomeia and indicate that current measures are likely to be sufficient for headwater streams supporting the Beddomeia populations investigated, but a precautionary approach is required for other species for which there is limited information, and extra conservation measures may be necessary for those species proven to be restricted to a low number of locations. vi Acknowledgements Numerous people and organisations contributed to the completion of this study, I wish now to acknowledge their assistance and express my sincere thanks. I wish to thank my supervisors Alastair Richardson, Sarah Munks, Winston Ponder and Leon Barmuta, for their continued support throughout this long journey and for their contributions to reviews of this thesis. The fieldwork component of this study could not have been completed without the generous assistance of volunteers. My thanks to each and every one, but, particular gratitude must be expressed to one volunteer, Qug (Kylie McKendrick King)*, for her ever enthusiastic, inspirational and positive attitude, who attended > 60% of field trips, providing endless laughter and who demonstrated continued enthusiasm for the wonders of nature, particularly copepods. Jo Carswell*, Jerry Romanski and Chris Spencer are also singled out for their exceptional contributions toward the fieldwork component of this research; however, the project could not have been possible without the gallant efforts of other volunteers, including: Mark Bridges*, John Green *,Billie Lazenby, Ingrid Mitchell, Abraham Miller, Greta Peters* and Simon Talbot (UTas), and Forestry Tasmania (Bass and Devonport districts) personnel: Errol Lohrey; Byron Yeo, Henry Chan, Daniel Bowden, Beven Schramm and Jeff Meggs. Two supervisors (Sarah Munks and Winston Ponder) also offered field assistance, many thanks; although no doubt the latter came to regret the decision! Appreciation must also expressed to the following people and organizations for their additional contribution to the fieldwork: Kathryn Redburn (through the Tasmanian Conservation Trust) and David Bennett (CSIRO student), during the pilot studies, and the Forest Practices Authority, for supporting David Bennett, for covering vehicular costs incurred during project and for providing additional field support in the guise of Chris Spencer and Suzette Wood. Gratitude is expressed to the Tasmanian Conservation Trust (TCT) and WWF for providing support funding for the fieldwork volunteers supplied through the TCC (*= through the TCT). Partial funding for the project was supplied by an Australian postgraduate scholarship award and the Forest Practices Authority. Additional funding for DNA extraction and supplementary field assistance was provided by the Tasmanian Department of Primary Industries, Water and Environment (Threatened Species Section); thanks in particular to Ray Brereton (TSS Senior vii Zoologist) and Dr Sally Bryant. DNA extraction and analysis could not have been completed without the continued support and enduring patience of the UTas molecular laboratory manager, Adam Smolenski, who provided instruction on DNA extraction techniques and analysis, and Winston Ponder for providing additional tuition in DNA sequence alignment and analyses as well as specimen dissection techniques. Thanks to you both. The Forest Practices Authority provided the majority of the support for this study, assisting also with GIS support provided by Daniel Livingston, staff support (taking on additional duties) and financial and time support during the final sprint toward completion, thanks all for their contribution. Recognition is given to Laurie Cook (Freshwater systems) for his interest in the project and clarification of sampling methodology, to John Gooderham for information on hydrobiid predation and to David Ratkowsky for statistical assistance and advice. Gratitude is expressed to CSIRO supported student, David Bennett for agreeing to undertake a project on hydrobiids which greatly assisted the project design and methodology. Finally, completion of this thesis would not have been possible without the continued and enduring support, both technical and emotional, from my partner, Chris Spencer, and my father, Brian Richards. Thank you both for your contributions. It is inevitable that a study such as this should bring together contributions and support from such a disparate group of individuals and organisations. I am thankful to each and every one for contributing to this research. viii Contents Abstract ........................................................................................................................................ v Acknowledgements .................................................................................................................... vii List of Figures ........................................................................................................................... xiii List of Tables ........................................................................................................................... xvii 1 Introduction ......................................................................................................................... 3 1.1 Hydrobiidae - a diverse group with narrow-range endemics ........................................ 3 1.2 Ecology and Biology of Hydrobiidae............................................................................ 4 1.3 Morphology and molecular studies ............................................................................... 5 1.4 Conservation management issues ................................................................................. 7 1.5 Hydrobiidae in Tasmania ............................................................................................ 11 1.6 Current management ................................................................................................... 12 1.7 Thesis aim and scope .................................................................................................