Teleost fishes occupy a range of ecosystem, and habitat types subject to large seasonal fluctuations. Temperate fishes, in particular, survive large seasonal shifts in temperature, light availability, and access to certain habitats. Mobile species such as lake trout () can behaviorally respond to seasonal variation by shifting their habitat deeper and further offshore in response to warmer surface water temperatures during the summer.
View Article and Find Full Text PDFPost-glacial colonization of lakes in Algonquin Park, Ontario, Canada resulted in food webs with cisco ( sensu lato) and either or spp. as the dominant diel migrator. as prey, its diel movements and benthic occupancy, are hypothesized to be key elements of ecological opportunity for cisco diversity in the Laurentian Great Lakes.
View Article and Find Full Text PDFThe ecological consequences of winter in freshwater systems are an understudied but rapidly emerging research area. Here, we argue that winter periods of reduced temperature and light (and potentially oxygen and resources) could play an underappreciated role in mediating the coexistence of species. This may be especially true for temperate and subarctic lakes, where seasonal changes in the thermal environment might fundamentally structure species interactions.
View Article and Find Full Text PDFThe diversity of Laurentian Great Lakes ciscoes (, sensu lato) arose via repeated local adaptive divergence including deepwater ciscoes that are now extirpated or threatened. The form, or Blackfin Cisco, is extirpated from the Great Lakes and remains only in Lake Nipigon. Putative populations were recently discovered in sympatry with in a historical drainage system of glacial Lake Algonquin, the precursor of lakes Michigan and Huron.
View Article and Find Full Text PDFDespite the fact that non-aqueous uranium chemistry is over 60 years old, most polarised-covalent uranium-element multiple bonds involve formal uranium oxidation states IV, V, and VI. The paucity of uranium(III) congeners is because, in common with metal-ligand multiple bonding generally, such linkages involve strongly donating, charge-loaded ligands that bind best to electron-poor metals and inherently promote disproportionation of uranium(III). Here, we report the synthesis of hexauranium-methanediide nanometre-scale rings.
View Article and Find Full Text PDFDetecting all species in a given survey is challenging, regardless of sampling effort. This issue, more commonly known as imperfect detection, can have negative impacts on data quality and interpretation, most notably leading to false absences for rare or difficult-to-detect species. It is important that this issue be addressed, as estimates of species richness are critical to many areas of ecological research and management.
View Article and Find Full Text PDFMating systems are an important factor influencing the variance in reproductive success among individuals within natural populations and thus have important ecological and evolutionary implications. We used molecular pedigree reconstruction techniques with microsatellite DNA data to characterize the genetic mating system and mate selection in adult smallmouth bass spawning in Lake Opeongo. The genetic mating system of smallmouth bass in this system can be characterized as predominantly monogamous with a low rate of polygynandry particularly among larger individuals.
View Article and Find Full Text PDFSpherical silver nanoparticles were prepared by means of ion beam synthesis in lithium niobate. The embedded nanoparticles were then irradiated with energetic (84)Kr and (197)Au ions, resulting in different electronic energy losses between 8.1 and 27.
View Article and Find Full Text PDFWe investigate the role of capillarity stresses on the ion-hammering phenomenon when sub-micrometer colloidal particles are considered. To this end, nearly monodisperse, chemically synthesized silica (SiO₂) colloids (100, 300 and 600 nm) were irradiated at room temperature (300 K) with 4 MeV Au ions for fluences up to Φ = 1.8 × 10¹⁶ cm⁻².
View Article and Find Full Text PDFSpecies present in communities are affected by the prevailing environmental conditions, and the traits that these species display may be sensitive indicators of community responses to environmental change. However, interpretation of community responses may be confounded by environmental variation at different spatial scales. Using a hierarchical approach, we assessed the spatial and temporal variation of traits in coastal fish communities in Lake Huron over a 5-year time period (2001-2005) in response to biotic and abiotic environmental factors.
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