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Full-Text Articles in Life Sciences
Temperature Effects On The Development Of The Axial Skeleton And Body Shape In Astyanax Mexicanus (Teleostei: Characidae), Joseph David Forberg
Temperature Effects On The Development Of The Axial Skeleton And Body Shape In Astyanax Mexicanus (Teleostei: Characidae), Joseph David Forberg
College of Science and Health Theses and Dissertations
Humans are causing large-scale changes in environmental conditions across the planet including in temperature. Changes in the environmental conditions can lead to phenotypic changes in ectotherms that affect adaptively important traits like body shape and the axial skeleton. Previous studies have shown that temperature changes during development significantly affects body shape and vertebral number in the Mexican tetra Astyanax mexicanus. How these changes arise early in development is not clear. In this study, I examine how changes in developmental temperature affect body shape in larval and juvenile fish, the order of ossification of elements of the axial skeleton, the size …
Phylogeography Of The Neotropical Fish Genus Rhoadsia (Teleostei: Characidae) In Ecuador, Roberto Valentino Cucalón Tamayo
Phylogeography Of The Neotropical Fish Genus Rhoadsia (Teleostei: Characidae) In Ecuador, Roberto Valentino Cucalón Tamayo
College of Science and Health Theses and Dissertations
Western Ecuador is considered a biodiversity hotspot. Nevertheless, studies of population genetic structure and variation are rare, especially in aquatic species. The genus Rhoadsia is an endemic freshwater fish in this region with two recognized species, Rhoadsia minor and R. altipinna. Little is known about the evolutionary relationships of their populations, and due to morphological similarities, their validity as distinct species has been questioned. The present study uses a phylogeographic approach to examine the evolutionary history of the genus and the validity of the two described species. Furthermore, I investigated the possible geographical origin of the genus based on patterns …
Genetic And Morphological Diversity Along Altitudinal Gradients In The Genus Rhoadsia (Teleostei: Characidae: Rhoadsiinae), Grace Malato
Genetic And Morphological Diversity Along Altitudinal Gradients In The Genus Rhoadsia (Teleostei: Characidae: Rhoadsiinae), Grace Malato
College of Science and Health Theses and Dissertations
The Neotropics have the highest fish species diversity of any area in the world, with some experts estimating that as many as 4000 species of fishes are present in freshwater ecosystems. Elevational gradients are partially responsible for this diversity due to the rapidly changing ecological conditions associated with changes in altitude in rivers. One area where elevational gradients are particularly important is Western Ecuador; this region forms part of a biodiversity hotspot extending south from Panama along the western side of the Andes. Fish species diversity is relatively low because of the small size of most of the river drainages …