Speckled dace (Rhinichthys osculus) is a small cyprinid that is geographically widespread throughout western North America, and the most frequently occurring sh in Oregon. Because of the genetic and morphological variation in this species across its range, it has been referred to as a "species complex" and no revision to...
Neotropical characiform fishes form one of the most diverse freshwater ichthyofauna in the world. Knowledge of evolutionary processes that generated and maintain the immense characiform lineage and morphological diversity is still poorly understood. When did characiform lineages diversify? How have major geological and environmental changes affected diversification? Why are some...
Dwelling on the bottom of large rivers to high alpine streams, freshwater sculpins (genus Cottus) occur in high densities across the Pacific Northwest, with 21 currently recognized species found in the Pacific Northwest. Sculpin fill many ecological roles, with some species serving as important prey sources, and others competing with...
Characiform fishes form one of the most diverse freshwater fish clades in the world. Comprising more than 2000 species and distributed primarily in South America and Africa, characiforms vary dramatically in their ecomorphology. However, the evolutionary processes responsible for the immense ecomorphological diversity remains unknown. Recently, a study postulated that...
Animal weapons are thought to have evolved to compete for reproductive opportunities within a species. Across the diverse weapon-bearing taxa, several evolutionary trends have emerged: (1) increasing complexity and relative size across ontogeny, (2) sexual dimorphism, and (3) higher levels of random deviations from symmetry (i.e., fluctuating asymmetry) than non-weaponized...
Accumulating human impacts on freshwater ecosystems have created a biodiversity crisis for freshwater fishes while conservation efficacy remains hampered by the Linnaean shortfall, the ignorance of many species that have yet to be discovered and described. The past discovery of most freshwater fish species was simply a matter of collecting...
The Speckled dace (Rhinichthys osculus) is the most widespread minnow in western North America (Gilbert and Williams, 2002). It has diversified widely across its range—both morphologically and genetically—and as such might rightly be called a species complex. Our ongoing work aims to determine where boundaries between potentially undescribed species lie...
RNAseq data among copepods (Calanus pacificus) were sampled and analyzed in relation to oceanographic and climatic conditions to determine if new information derived from such an approach might assist applications that use copepods as ecosystem indicators to predict fishery yields. These samples were taken as part of long-term studies conducted...
Diversité et distribution des poissons anostomoides (Teleostei, Characiformes) dans les Guyanes.
Cinquante-six espèces, soit approximativement 20% des Characiformes de la superfamille des Anostomidea (familles
des Anostomidae, Chilodontidae, Curimatidae et Prochilodontidae), fréquentent les eaux douces de la Guyane française, du
Guyana et du Suriname bien que ces régions ne recouvrent qu’environ...
Global amphibian declines have been attributed to numerous and often synergistic causes, such as invasive species, pathogens, and ultraviolet-B (UV-B) radiation. The effects of these stressors are context dependent and can vary with location, species, and populations. As sensitivity to UV-B has shown inconsistencies across amphibian taxa, it can be...