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Full-Text Articles in Life Sciences
Vital Rates And Population Demographics In Declining And Stable Watersnake Populations, John H. Roe, Omar Attum, Bruce A. Kingsbury Ph.D.
Vital Rates And Population Demographics In Declining And Stable Watersnake Populations, John H. Roe, Omar Attum, Bruce A. Kingsbury Ph.D.
Bruce A Kingsbury Ph.D.
many snake populations have experienced significant declines, including the copper-bellied Watersnake (nerodia erythrogaster neglecta), a species listed as threatened under the federal endangered species act. here, we assess aspects of population biology and vital rates in n. e. neglecta to help elucidate potential mechanisms of their decline and inform more targeted recovery efforts. We use the common Watersnake (nerodia sipedon sipedon) as a benchmark for comparison. survey results indicate that the n. e. neglecta population may have experienced a 70% decline in abundance from 2001– 2006, whereas the n. s. sipedon population remained relatively stable. annual survivorship rates did not …
Tradeoffs Of Warm Adaptation In Aquatic Ectotherms: Live Fast, Die Young?, Eloy Martinez, Anthony P. Porreca, Robert E. Colombo, Michael A. Menze
Tradeoffs Of Warm Adaptation In Aquatic Ectotherms: Live Fast, Die Young?, Eloy Martinez, Anthony P. Porreca, Robert E. Colombo, Michael A. Menze
Eloy Martinez
In the face of a changing climate, questions regarding sub-lethal effects of elevated habitat temperature on the physiology of ectotherms remain unanswered. In particular, long-term responses of ectotherms to the warming trend in tropical regions are unknown, and understudied due to the difficulties in specimen and community traceability. In freshwater lakes employed as cooling reservoirs for power plants, increased physiological stress from high water temperature can potentially alter the community structure of fishes. We employ this highly tractable system to assess how thermal regimes can alter the physiology and ecology of aquatic species. We documented a significantly reduced lifespan, growth …
Predicting The Physiological Performance Of Ectotherms In Fluctuating Thermal Environments, Michael W. Sears, A C. Niehaus, M J. Angilletta, C E. Franklin, R S. Wilson
Predicting The Physiological Performance Of Ectotherms In Fluctuating Thermal Environments, Michael W. Sears, A C. Niehaus, M J. Angilletta, C E. Franklin, R S. Wilson
Michael W. Sears
Physiological ecologists have long sought to understand the plasticity of organisms in environments that vary widely among years, seasons and even hours. This is now even more important because human-induced climate change is predicted to affect both the mean and variability of the thermal environment. Although environmental change occurs ubiquitously, relatively few researchers have studied the effects of fluctuating environments on the performance of developing organisms. Even fewer have tried to validate a framework for predicting performance in fluctuating environments. Here, we determined whether reaction norms based on performance at constant temperatures (18, 22, 26, 30 and 34°C) could be …
Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam
Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam
Richard A. Long
We tested the application of 5-bromo-2’-deoxyuridine (BrdU), a thymidine analogue that becomes incorporated into DNA during growth, to measure growth rates of individual marine bacteria cells. Immunocytochemical detection of BrdU incorporation into bacterial DNA has the potential for single-cell-based growth measurement. Optimized procedure for immunocytochemistry was applicable to 14 marine heterotrophic bacterial isolates belonging to g-proteobacteria, α-proteobacteria, Cytophaga-Flavobacterium-Bacteroides (CFB) group and Gram-positive bacteria. The relationship between cell-specific fluorescence intensity and specific growth rate was linearly correlated among CFB group isolates, which indicated a potential of the method for quantitative measurement. Analysis of the detection limit indicated …
Coupling Between Bacterioplankton Species Composition, Population Dynamics, And Organic Matter Degradation, Jarone Pinhassi, Farooq Azam, Johanna Hemphälä, Richard A. Long, Josefina Martinez, Ulla Li Zweifel, Åke Hagström
Coupling Between Bacterioplankton Species Composition, Population Dynamics, And Organic Matter Degradation, Jarone Pinhassi, Farooq Azam, Johanna Hemphälä, Richard A. Long, Josefina Martinez, Ulla Li Zweifel, Åke Hagström
Richard A. Long
To study the effect of substrate addition on short term bacterial population dynamics and species composition in seawater mesocosms were maintained with water collected off Scripps Pier (La Jolla, California USA) Protein enrichment (BSA) triggered a dynamic response from the microbial food web, whereas enrichment with starch had no effect. In the protein enriched mesocosm the number of both nucleoid-containing cells and metabolically active cells increased by 3.0 X 105 cells ml-1 from Day 1 to Day 4 In the same time period the density of a set of 31 phylogenetically different bacteria (α- and g-Proteobactena as well as Flexibacter-Cytophaga-Bacteroides) …