Thesis
Conservation genetics and the Australian lungfish Neoceratodus forsteri; a spatio-temporal study of population structure
University of the Sunshine Coast, Queensland
Master of Science, University of the Sunshine Coast
2003
DOI:
https://doi.org/10.25907/00380
Abstract
Neoceratodus forsteri is a phylogenetically distinct ancient lineage with a natural distribution restricted to 3 catchments in the southeast Queensland region. Modifications to the river systems they are restricted to has prompted concern for the persistence of this species in the face of such changes. Accordingly, ecological and molecular surveys have been undertaken to identify the management units in order to design and implement a sound management strategy. Ecological surveys of the Burnett catchment have highlighted that compounding factors of longevity, low reproductive output and loss of suitable spawning sites through seasonal fluctuations as well as habitat degradation have greatly reduced juvenile recruitment rates. Genetic surveys investigating allozyme , mtDNA and microsatellite markers show that despite substantial barriers to gene flow, lungfish populations comprise of one homogenous population. This lack of diversity was attributed to historic and present bottleneck events, as well as to historic fluvial connectivity. To obtain a broader snapshot of the genome, this survey developed and screened RAF and AFLP multi-locus markers, as well as a microsatellite library. Moreover, in a study complementing previous ATPase survey of contemporary populations, sequence data from this region was evaluated from formalin preserved adult specimens (collection dates range between 1912 and 1976). This study has shown that the common ATPase haplotype found in contemporary populations was also present among specimens collected from 1912. Further, the high prevalence of rare alleles recorded from modern Mary populations was also recorded from formalin preserved specimens. AFLP banding profiles were monomorphic; by contrast, variation detected by RAF markers identified significant patterns of substructure between catchments. Significant structure was also recorded between impounded populations and non-impounded populations. Lungfish populations have a relatively narrow range and occur within regulated fluvial systems. Habitat degradation is implicated in reduction of spawning sites. Combined with low juvenile recruitment these effects greatly reduce the effective population size. The phyletic age of this species, in conjunction with low genetic diversity greatly increases its vulnerability to environmental change or novel diseases. In accordance with the World Conservation Union (IUCN), genetic diversity is one of three recognised levels requiring conservation.
Details
- Title
- Conservation genetics and the Australian lungfish Neoceratodus forsteri; a spatio-temporal study of population structure
- Authors
- Iman Lissone
- Contributors
- Alison Shapcott (Supervisor)Jenny Ovenden (Supervisor)
- Awarding institution
- University of the Sunshine Coast
- Degree awarded
- Master of Science
- Publisher
- University of the Sunshine Coast, Queensland
- DOI
- 10.25907/00380
- Organisation Unit
- School of Science and Engineering - Legacy; University of the Sunshine Coast, Queensland; School of Science, Technology and Engineering; Centre for Bioinnovation
- Language
- English
- Record Identifier
- 99450016502621
- Output Type
- Thesis
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