Molecular phylogenetics and biogeography of galaxiid fishes (Osteichthyes: Galaxiidae): dispersal, vicariance, and the position of Lepidogalaxias salamandroides.
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The species-rich genus Galaxias is shown to be polyphyletic and the generic taxonomy of the Galaxiinae is reassessed in the light of phylogenetic relationships, and the loss of this migratory phase may be a major cause of speciation.Abstract:
The galaxiid fishes exhibit a gondwanan distribution. We use mitochondrial DNA sequences to test conflicting vicariant and dispersal biogeographic hypotheses regarding the Southern Hemisphere range of this freshwater group. Although phylogenetic resolution of cytochrome b and 16S rRNA sequences is largely limited to more recent divergences, our data indicate that the radiation can be interpreted as several relatively recent dispersal events superimposed on an ancient gondwanan radiation. Genetic relationships contradict the findings of recent morphological analyses of galaxioid fishes. In particular, we examine several hypotheses regarding phylogenetic placement of the enigmatic Lepidogalaxias. Although most workers consider Lepidogalaxias to be an unusual scaled member of the Southern Hemisphere galaxioids, it has also been suggested that this species is related to the Northern Hemisphere esocoids. Our data strongly suggest that this species is not a galaxiid, and the alternative hypothesized esocoid relationship cannot be rejected. The species-rich genus Galaxias is shown to be polyphyletic and the generic taxonomy of the Galaxiinae is reassessed in the light of phylogenetic relationships. Juvenile saltwater-tolerance is phylogenetically distributed throughout the Galaxiinae, and the loss of this migratory phase may be a major cause of speciation.read more
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The Tasmanian Lake Shrimps, Paranaspides Smith, 1908 (Crustacea, Syncarida, Anaspidesidae)
TL;DR: It is shown that Paranaspides from Arthurs Lake and Woods Lakes are referrable to a new species, P. williamsi sp.
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Ontogenetic changes in morphology of flathead galaxiid fishes (Osmeriformes: Galaxiidae) in South Island, New Zealand
TL;DR: Ontogenetic changes in morphology of four non-migratory ‘flathead’ galaxiid fishes and interspecific differences suggest that habitat use changes with size and interspecific differences shown in geometric shape require structural linkages before suggestions can be made on identification or systematics.
Journal ArticleDOI
Genotypic and morphological variation between Galaxiella nigrostriata (Galaxiidae) populations: implications for conservation
David M. Galeotti,Mark A. Castalanelli,Mark A. Castalanelli,David Groth,Clint McCullough,Clint McCullough,Mark Lund +6 more
TL;DR: It is postulate G. nigrostriata distribution last expanded in the early Pleistocene ~5.1 million years ago and have since been restricted to remnant wetlands in the immediate area and conservation efforts are required to ensure the survival of these genetically and morphologically distinctive Swan coastal plain populations.
Dissertation
The ecological impacts of secondary salinisation on halo-tolerant fishes in south-western Australia
TL;DR: The size, morphology, life-cycle, diet and rate of parasitism between populations in the upper and lower catchment of native and exotic freshwater fishes in different parts of the Blackwood River is investigated.
References
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