scholarly journals Intraspecific variation in metabolic rate and its correlation with local environment in the Chinese scorpion Mesobuthus martensii

Biology Open ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. bio041533
Author(s):  
Wei Wang ◽  
Gao-Ming Liu ◽  
De-Xing Zhang
Keyword(s):  
Metabolic Rate ◽  
Intraspecific Variation ◽  
Local Environment

scholarly journals Metabolic traits in brown trout (Salmo trutta) vary in response to food restriction and intrinsic factors

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Louise C Archer ◽  
Stephen A Hutton ◽  
Luke Harman ◽  
W Russell Poole ◽  
Patrick Gargan ◽  
...  
Keyword(s):  
Life History ◽  
Metabolic Rate ◽  
Intraspecific Variation ◽  
Brown Trout ◽  
Environmental Conditions ◽  
Food Restriction ◽  
Metabolic Rates ◽  
Intrinsic Factors ◽  
Metabolic Traits ◽  
Food Conditions

Abstract Metabolic rates vary hugely within and between populations, yet we know relatively little about factors causing intraspecific variation. Since metabolic rate determines the energetic cost of life, uncovering these sources of variation is important to understand and forecast responses to environmental change. Moreover, few studies have examined factors causing intraspecific variation in metabolic flexibility. We explore how extrinsic environmental conditions and intrinsic factors contribute to variation in metabolic traits in brown trout, an iconic and polymorphic species that is threatened across much of its native range. We measured metabolic traits in offspring from two wild populations that naturally show life-history variation in migratory tactics (one anadromous, i.e. sea-migratory, one non-anadromous) that we reared under either optimal food or experimental conditions of long-term food restriction (lasting between 7 and 17 months). Both populations showed decreased standard metabolic rates (SMR—baseline energy requirements) under low food conditions. The anadromous population had higher maximum metabolic rate (MMR) than the non-anadromous population, and marginally higher SMR. The MMR difference was greater than SMR and consequently aerobic scope (AS) was higher in the anadromous population. MMR and AS were both higher in males than females. The anadromous population also had higher AS under low food compared to optimal food conditions, consistent with population-specific effects of food restriction on AS. Our results suggest different components of metabolic rate can vary in their response to environmental conditions, and according to intrinsic (population-background/sex) effects. Populations might further differ in their flexibility of metabolic traits, potentially due to intrinsic factors related to life history (e.g. migratory tactics). More comparisons of populations/individuals with divergent life histories will help to reveal this. Overall, our study suggests that incorporating an understanding of metabolic trait variation and flexibility and linking this to life history and demography will improve our ability to conserve populations experiencing global change.

Morphological relationships among subspecies of the Rufous-collared Sparrow, Zonotrichia capensis

1985 ◽  
Vol 63 (10) ◽  
pp. 2383-2388 ◽  
Author(s):  
Paul Handford
Keyword(s):  
Intraspecific Variation ◽  
Environmental Effects ◽  
Local Environment ◽  
Andes Mountains ◽  
Museum Specimens ◽  
High Latitudes ◽  
High Altitudes ◽  
Southern Andes ◽  
Zonotrichia Capensis ◽  
Phenetic Relationships

The phenetic relationships among 22 described subspecies of Zonotrichia capensis, the Rufous-collared Sparrow, are investigated by analyses of variation in six external metric variables taken from over 1500 museum specimens. Both sexes show the same marked dichotomy between two groups of subspecies: pulacayensis, sanborni, antofagastae, chilensis, choraules, and australis versus all others. These six subspecies are from temperate high altitudes and high latitudes and occupy a geographically contiguous region in the southern Andes mountains and Patagonia. Within these two subgroups there is extensive overlap among individuals; finer division of the subspecies is difficult, and involves the association of subspecies from geographically disjunct regions. Thus the taxonomic hierarchy appears to be a poor representation of variation of the characters considered here. The association of geographically disjunct forms suggests that intraspecific variation in these characters reflects the local environment (via selection and (or) environmental effects) rather than historical (genealogical) relationships.

scholarly journals Ecological and evolutionary consequences of metabolic rate plasticity in response to environmental change

2019 ◽  
Vol 374 (1768) ◽  
pp. 20180180 ◽  
Author(s):  
Tommy Norin ◽  
Neil B. Metcalfe
Keyword(s):  
Environmental Change ◽  
Metabolic Rate ◽  
Intraspecific Variation ◽  
Standard Metabolic Rate ◽  
Metabolic Rates ◽  
Trade Offs ◽  
Fitness Consequences ◽  
Organ Tissue ◽  
Evolutionary Consequences ◽  
Response To Environmental Change

Basal or standard metabolic rate reflects the minimum amount of energy required to maintain body processes, while the maximum metabolic rate sets the ceiling for aerobic work. There is typically up to three-fold intraspecific variation in both minimal and maximal rates of metabolism, even after controlling for size, sex and age; these differences are consistent over time within a given context, but both minimal and maximal metabolic rates are plastic and can vary in response to changing environments. Here we explore the causes of intraspecific and phenotypic variation at the organ, tissue and mitochondrial levels. We highlight the growing evidence that individuals differ predictably in the flexibility of their metabolic rates and in the extent to which they can suppress minimal metabolism when food is limiting but increase the capacity for aerobic metabolism when a high work rate is beneficial. It is unclear why this intraspecific variation in metabolic flexibility persists—possibly because of trade-offs with the flexibility of other traits—but it has consequences for the ability of populations to respond to a changing world. It is clear that metabolic rates are targets of selection, but more research is needed on the fitness consequences of rates of metabolism and their plasticity at different life stages, especially in natural conditions. This article is part of the theme issue ‘The role of plasticity in phenotypic adaptation to rapid environmental change’.

Residual Gas Reaction in the Electron Microscope: II The Design of a Gas-Control Chamber for Quantitative Observations

1969 ◽  
Vol 27 ◽  
pp. 82-83
Author(s):  
Chester J. Calbick ◽  
Richard E. Hartman
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Local Environment ◽  
Chamber Pressure ◽  
Objective Lens ◽  
Ion Pump ◽  
Quantitative Studies ◽  
Precise Knowledge ◽  
Differential Pumping ◽  
And Control

Quantitative studies of the phenomenon associated with reactions induced by the electron beam between specimens and gases present in the electron microscope require precise knowledge and control of the local environment experienced by the portion of the specimen in the electron beam. Because of outgassing phenomena, the environment at the irradiated portion of the specimen is very different from that in any place where gas pressures and compositions can be measured. We have found that differential pumping of the specimen chamber by a 4" Orb-Ion pump, following roughing by a zeolite sorption pump, can produce a specimen-chamber pressure 100- to 1000-fold less than that in the region below the objective lens.

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