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Phylogeography and population structure of two loach species (Teleostei: Nemacheilidae) in Southeast Asia
Dvořák, Tomáš ; Bohlen, Jörg (advisor) ; Říčan, Oldřich (referee)
The freshwater fish species Schistura robertsi and Paracanthocobitis zonalternans belong to the family Nemacheilidae, which is distributed across whole Eurasia and with one species in northeast Africa. P. zonalternans occurs in lowland habitats through western Southeast Asia from Central Myanmar until northern Malaysia. The distribution area is of biogeographic interest, because it crosses several known biogeographic barriers, namely the border between Indian and Indochinese freshwater fauna along the Salween River, the Isthmus of Kra, the Krabi - Surat Thani line and the Kangar - Pattani line. In the present study, around 250 specimens of P. zonalternans from 62 localities across the whole distribution area were investigated using genetic (nuclear and mitochondrial sequences), morphologic and geologic data. The genetic data reveal the existence of seven major clades within the analysed material, each of them with a distinct geographic distribution area and only few cases of overlap, but with occurrence of some cases of secondary contact. Divergence time estimations suggested that P. zonalternans is about 18 my old, and a biogeographic analysis located the region of origin in the Tenasserim region (nowadays southern Myanmar). The global sea level fluctuations seem to have had a strong impact on the...
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Phylogeography and population structure of two loach species (Teleostei: Nemacheilidae) in Southeast Asia
Dvořák, Tomáš ; Bohlen, Jörg (advisor) ; Říčan, Oldřich (referee)
The freshwater fish species Schistura robertsi and Paracanthocobitis zonalternans belong to the family Nemacheilidae, which is distributed across whole Eurasia and with one species in northeast Africa. P. zonalternans occurs in lowland habitats through western Southeast Asia from Central Myanmar until northern Malaysia. The distribution area is of biogeographic interest, because it crosses several known biogeographic barriers, namely the border between Indian and Indochinese freshwater fauna along the Salween River, the Isthmus of Kra, the Krabi - Surat Thani line and the Kangar - Pattani line. In the present study, around 250 specimens of P. zonalternans from 62 localities across the whole distribution area were investigated using genetic (nuclear and mitochondrial sequences), morphologic and geologic data. The genetic data reveal the existence of seven major clades within the analysed material, each of them with a distinct geographic distribution area and only few cases of overlap, but with occurrence of some cases of secondary contact. Divergence time estimations suggested that P. zonalternans is about 18 my old, and a biogeographic analysis located the region of origin in the Tenasserim region (nowadays southern Myanmar). The global sea level fluctuations seem to have had a strong impact on the...
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