Does the thermal plasticity of metabolic enzymes underlie thermal compensation of locomotor performance in the eastern newt (Notophthalmus viridescens)?

2015 ◽  
Vol 323 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Patrick M. Mineo ◽  
Paul J. Schaeffer
Keyword(s):  
Metabolic Enzymes ◽  
Notophthalmus Viridescens ◽  
Locomotor Performance ◽  
Thermal Compensation ◽  
Thermal Plasticity ◽  
Eastern Newt

scholarly journals Thermal reaction norms of key metabolic enzymes reflect divergent physiological and behavioral adaptations of closely related amphipod species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lena Jakob ◽  
Kseniya P. Vereshchagina ◽  
Anette Tillmann ◽  
Lorena Rivarola-Duarte ◽  
Denis V. Axenov-Gribanov ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Lake Baikal ◽  
Enzyme Activities ◽  
Large Scale ◽  
Metabolic Enzymes ◽  
Thermal Reaction ◽  
Reaction Norms ◽  
Ecological Niches ◽  
Amphipod Species ◽  
Thermal Plasticity

AbstractLake Baikal is inhabited by more than 300 endemic amphipod species, which are narrowly adapted to certain thermal niches due to the high interspecific competition. In contrast, the surrounding freshwater fauna is commonly represented by species with large-scale distribution and high phenotypic thermal plasticity. Here, we investigated the thermal plasticity of the energy metabolism in two closely-related endemic amphipod species from Lake Baikal (Eulimnogammarus verrucosus; stenothermal and Eulimnogammarus cyaneus; eurythermal) and the ubiquitous Holarctic amphipod Gammarus lacustris (eurythermal) by exposure to a summer warming scenario (6–23.6 °C; 0.8 °C d−1). In concert with routine metabolic rates, activities of key metabolic enzymes increased strongly with temperature up to 15 °C in E. verrucosus, whereupon they leveled off (except for lactate dehydrogenase). In contrast, exponential increases were seen in E. cyaneus and G. lacustris throughout the thermal trial (Q10-values: 1.6–3.7). Cytochrome-c-oxidase, lactate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase activities were found to be higher in G. lacustris than in E. cyaneus, especially at the highest experimental temperature (23.6 °C). Decreasing gene expression levels revealed some thermal compensation in E. cyaneus but not in G. lacustris. In all species, shifts in enzyme activities favored glycolytic energy generation in the warmth. The congruent temperature-dependencies of enzyme activities and routine metabolism in E. verrucosus indicate a strong feedback-regulation of enzymatic activities by whole organism responses. The species-specific thermal reaction norms reflect the different ecological niches, including the spatial distribution, distinct thermal behavior such as temperature-dependent migration, movement activity, and mating season.

Rapid Change in Life-Cycle Polyphenism across a Subspecies Boundary of the Eastern Newt, Notophthalmus viridescens

2011 ◽  
Vol 45 (3) ◽  
pp. 379-384 ◽  
Author(s):  
Mizuki K. Takahashi ◽  
Yukiko Y. Takahashi ◽  
Matthew J. Parris
Keyword(s):  
Life Cycle ◽  
Rapid Change ◽  
Notophthalmus Viridescens ◽  
Eastern Newt

scholarly journals Can the impacts of cold-water pollution on fish be mitigated by thermal plasticity?

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
M A Parisi ◽  
R L Cramp ◽  
M A Gordos ◽  
C E Franklin
Keyword(s):  
Water Pollution ◽  
Metabolic Rate ◽  
Water Temperature ◽  
Cold Water ◽  
Thermal Sensitivity ◽  
Exposure Period ◽  
Thermal Pollution ◽  
Locomotor Performance ◽  
Thermal Plasticity ◽  
The Impact

Abstract Increasingly, cold-water pollution (CWP) is being recognised as a significant threat to aquatic communities downstream of large, bottom-release dams. Cold water releases typically occur during summer when storage dams release unseasonably cold and anoxic hypolimnetic waters, which can decrease the temperature of downstream waters by up to 16°C. Depending on the release duration, these hypothermic conditions can persist for many months. The capacity of ectothermic species to tolerate or rapidly adjust to acute temperature changes may determine the nature and magnitude of the impact of CWP on affected species. This study assessed the impacts of an acute reduction in water temperature on the physiological function and locomotor performance of juvenile silver perch (Bidyanus bidyanus) and examined their capacity to thermally compensate for the depressive effects of low temperatures via phenotypic plasticity. Locomotor performance (Ucrit and Usprint) and energetic costs (routine and maximum metabolic rate) were measured at multiple points over a 10-week period following an abrupt 10°C drop in water temperature. We also measured the thermal sensitivity of metabolic enzymes from muscle samples taken from fish following the exposure period. Cold exposure had significant depressive effects on physiological traits, resulting in decreases in performance between 10% and 55%. Although there was partial acclimation of Ucrit (~35% increase in performance) and complete compensation of metabolic rate, this occurred late in the exposure period, meaning silver perch were unable to rapidly compensate for the depressive effects of thermal pollution. The results of this study have substantial implications for the management of cold water releases from large-scale dams and the conservation of native freshwater fish species, as this form of thermal pollution can act as a barrier to fish movement, cause reduced recruitment, ecological community shifts and disruptions to timing and success of reproduction.

Eastern Newt (Notophthalmus viridescens) larvae alter morphological but not chemical defenses in response to predator cues

2014 ◽  
Vol 92 (4) ◽  
pp. 279-283 ◽  
Author(s):  
Kelly H. Brossman ◽  
Bradley E. Carlson ◽  
Amber N. Stokes ◽  
Tracy Langkilde
Keyword(s):  
Phenotypic Plasticity ◽  
Larval Stage ◽  
Species Interactions ◽  
Tail Length ◽  
Morphological Plasticity ◽  
Chemical Defenses ◽  
Notophthalmus Viridescens ◽  
Predator Cues ◽  
Eastern Newt ◽  
Larval Toxicity

Prey traits are often modified in response to exposure to predators, a phenomenon known as predator-induced phenotypic plasticity. Morphological plasticity in response to predator cues is well documented in amphibians; however, predator-induced chemical defenses have received relatively little attention. The Eastern Newt (Notophthalmus viridescens (Rafinesque, 1820)), which possesses tetrodotoxin—a toxin for chemical defense, is most vulnerable to predation during its larval stage. We assessed whether exposing Eastern Newt larvae to predator scent cues (from dragonfly larvae) would elicit change in their morphological and chemical defenses. Newt larvae exposed to scent cues of predatory dragonfly larvae exhibited significantly greater tail depths, which should increase survival of attempted predation by allowing them to swim faster, but did not differ in mass, snout–vent length, or tail length. Toxin concentrations in newt larvae were not significantly affected by exposure to these predator cues. Larval toxicity may be derived maternally or environmentally and is inflexible, or induced toxicity may only be detectable later in development. Predator-induced phenotypic plasticity, especially of chemical defenses, warrants greater attention, as potentially important outcomes of species interactions remain unclear.

Changes in the gut microbial community of the eastern newt (Notophthalmus viridescens) across its three distinct life stages

2021 ◽  
Vol 97 (3) ◽  
Author(s):  
Samantha S Fontaine ◽  
Patrick M Mineo ◽  
Kevin D Kohl
Keyword(s):  
Microbial Community ◽  
Community Assembly ◽  
Developmental Stages ◽  
Life Stage ◽  
Complex Life Cycle ◽  
Notophthalmus Viridescens ◽  
Selective Forces ◽  
Eastern Newt ◽  
Two Stages ◽  
Gut Microbial Community

ABSTRACT Understanding the forces that shape vertebrate gut microbial community assembly and composition throughout development is a major focus of the microbiome field. Here, we utilize the complex life cycle of the eastern newt (Notophthalmus viridescens) as a natural wild model to compare the effects of host and environmental factors on gut microbiome development. We compared bacterial inventories of each of the newt's three physiologically distinct developmental stages to determine if each hosted a unique community, or if the two stages which share an aquatic habitat (larvae and adults) harbored more similar communities than those of the third stage, the terrestrial juvenile eft. Additionally, we assessed how the contribution of selective processes to gut microbial assembly changed through development. We found that structurally, each life stage harbored a distinct community, which may be attributable to host factors. Further, across development, we found that community assembly processes shifted from a predominance of neutral to selective forces. However, habitat may also be important in determining community membership and diversity due the uniqueness of eft communities based on these metrics. Our results are similar to those in other vertebrate taxa, suggesting that gut microbiota assembly processes may be conserved across diverse lineages.

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