Genetic and ecological investigations of European populations of the pool frog, Rana lessonae (Camerano, 1882) with allied, osteological and species identification methods
Snell, Charles A. (2006) Genetic and ecological investigations of European populations of the pool frog, Rana lessonae (Camerano, 1882) with allied, osteological and species identification methods. PhD thesis, University of Greenwich.Full text not available from this repository.
Current identification methods for distinguishing north-west European brown and water frogs are discussed and tested, to allow the presentation here, of more accurate guidance on their separation. Novel methods for the identification of species and individuals including novel, non-invasive, biometrical methods have been developed.
Random amplified DNA (RAPD) analyses were used to clarify the native British status for pool frog, Rana lessonae. Using nine arbitrary primers, 160 polymorphisms were detected in 174 pool frogs from 11 European locations. Clear geographical groupings were recorded, and the Norfolk, Norwegian and Swedish individuals formed a closely related northern clade. Phylograms constructed from RAPD data were consistent with an unexpected post-glacial colonisation route, in which the northern clade derived from migration out of Italy, via Hungary and Poland, but cryptic glacial refugia in Eastern Europe are an alternative explanation. Similarity indices suggested a complex origin for the Swiss population which also supported more northerly refugia than traditionally assumed. The RAPD analyses concur with a parallel microsatellite investigation supporting native status for Norfolk pool frogs, and have helped to prompt a programme for re-establishing the northern clade in England after extinction in the 1990s.
Field research (in S.E. London) is also reported here which demonstrated extreme population changes in native amphibians, including the apparent extinction of water frogs; potential ecological causes are discussed. Population monitoring showed evidence for multiple spawnings in the same year by the same individual female water frogs (behaviour that is disputed by some herpetologists).
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||Rana temporaria, Rana lessonae, frogs, amphibians, species identification, ecology|
|Subjects:||Q Science > QL Zoology|
|Faculty / Department / Research Groups:||Faculty of Engineering & Science > Department of Life & Sports Science|
|Last Modified:||17 Oct 2016 09:11|
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