scholarly journals Differential effects of food availability on minimum and maximum rates of metabolism

2016 ◽  
Vol 12 (10) ◽  
pp. 20160586 ◽  
Author(s):  
Sonya K. Auer ◽  
Karine Salin ◽  
Agata M. Rudolf ◽  
Graeme J. Anderson ◽  
Neil B. Metcalfe
Keyword(s):  
Food Availability ◽  
Brown Trout ◽  
Environmental Conditions ◽  
Salmo Trutta ◽  
Positive Function ◽  
Energetic Cost ◽  
Metabolic Rates ◽  
Metabolic Power ◽  
Aerobic Scope ◽  
Cost Of Living

Metabolic rates reflect the energetic cost of living but exhibit remarkable variation among conspecifics, partly as a result of the constraints imposed by environmental conditions. Metabolic rates are sensitive to changes in temperature and oxygen availability, but effects of food availability, particularly on maximum metabolic rates, are not well understood. Here, we show in brown trout ( Salmo trutta ) that maximum metabolic rates are immutable but minimum metabolic rates increase as a positive function of food availability. As a result, aerobic scope (i.e. the capacity to elevate metabolism above baseline requirements) declines as food availability increases. These differential changes in metabolic rates likely have important consequences for how organisms partition available metabolic power to different functions under the constraints imposed by food availability.

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.

scholarly journals Food availability in spring affects smolting in brown trout (Salmo trutta)

2015 ◽  
Vol 72 (11) ◽  
pp. 1694-1699 ◽  
Author(s):  
Douglas A. Jones ◽  
Eva Bergman ◽  
Larry Greenberg
Keyword(s):  
Seasonal Variation ◽  
Food Availability ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Morphological Changes ◽  
Salmonid Fish ◽  
Fish Growth ◽  
Brown Trout Salmo Trutta ◽  
Previous Autumn

Prior to out-migration, salmonid fish typically undergo physiological and morphological changes — a process known as smolting. This study indicates that smolting in brown trout (Salmo trutta) is affected by feeding conditions in spring immediately prior to out-migration. This conclusion was reached after experimentally testing the effect of seasonal variation in food availability on smolt status in the spring. A migratory strain of trout was administered either high or low food rations in the autumn, winter, or spring prior to release in the spring. While fish growth or condition could be affected in any season, it was spring rationing that reduced growth and growth-related variables and that caused increased smolting. Our result supports the idea that smoltification and the decision to migrate is affected by spring food availability regardless of conditions in the previous autumn or winter.

scholarly journals Aerobic scope explains individual variation in feeding capacity

2015 ◽  
Vol 11 (11) ◽  
pp. 20150793 ◽  
Author(s):  
Sonya K. Auer ◽  
Karine Salin ◽  
Graeme J. Anderson ◽  
Neil B. Metcalfe
Keyword(s):  
Food Availability ◽  
Performance Measures ◽  
Salmo Trutta ◽  
High Standard ◽  
Standard Metabolic Rate ◽  
Aerobic Scope ◽  
Improve Performance ◽  
Low Levels ◽  
The Difference ◽  
Juvenile Brown Trout

Links between metabolism and components of fitness such as growth, reproduction and survival can depend on food availability. A high standard metabolic rate (SMR; baseline energy expenditure) or aerobic scope (AS; the difference between an individual's maximum and SMR) is often beneficial when food is abundant or easily accessible but can be less important or even disadvantageous when food levels decline. While the mechanisms underlying these context-dependent associations are not well understood, they suggest that individuals with a higher SMR or AS are better able to take advantage of high food abundance. Here we show that juvenile brown trout ( Salmo trutta ) with a higher AS were able to consume more food per day relative to individuals with a lower AS. These results help explain why a high aerobic capacity can improve performance measures such as growth rate at high but not low levels of food availability.

Winter Habitat Utilization by Stream Resident Brook Trout (Salvelinus fontinalis) and Brown Trout (Salmo trutta)

1986 ◽  
Vol 43 (10) ◽  
pp. 1970-1981 ◽  
Author(s):  
Richard A. Cunjak ◽  
Geoffrey Power
Keyword(s):  
Brown Trout ◽  
Brook Trout ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Focal Point ◽  
Age Groups ◽  
Habitat Utilization ◽  
Point Sources ◽  
Energetic Cost ◽  
Brown Trout Salmo Trutta

Habitat utilization by brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) is described from three winters of underwater observations in a southern Ontario river. Older trout (>age 1) generally occupied positions in deeper and faster water than age 0+ trout. In winter, at sites of sympatry, brown trout occupied greater focal point water depths than brook trout; both species had similar focal point water velocities. At all sites, and for both age groups and species, there was a strong preference for positions beneath cover. Relative to summer, trout positions in winter were characterized by slower water velocities and greater overhead cover, In winter, most trout were in aggregations, usually in pools beneath cover and close to point sources of groundwater discharge. Gregarious behaviour appeared to increase as water temperatures decreased; no such relationship was evident in the summer. Specific strategies for overwintering varied between sites and age groups but generally conformed to the theory of energetic cost minimization for position choice. These variable patterns appear to be adaptive.

scholarly journals Fish introductions reveal the temperature dependence of species interactions

2014 ◽  
Vol 281 (1775) ◽  
pp. 20132641 ◽  
Author(s):  
Catherine L. Hein ◽  
Gunnar Öhlund ◽  
Göran Englund
Keyword(s):  
Climate Change ◽  
Brown Trout ◽  
Environmental Conditions ◽  
Species Interactions ◽  
Salmo Trutta ◽  
Climate Impacts ◽  
Context Dependency ◽  
Large Lakes ◽  
Widespread Occurrence ◽  
Fish Introductions

A major area of current research is to understand how climate change will impact species interactions and ultimately biodiversity. A variety of environmental conditions are rapidly changing owing to climate warming, and these conditions often affect both the strength and outcome of species interactions. We used fish distributions and replicated fish introductions to investigate environmental conditions influencing the coexistence of two fishes in Swedish lakes: brown trout ( Salmo trutta ) and pike ( Esox lucius ). A logistic regression model of brown trout and pike coexistence showed that these species coexist in large lakes (more than 4.5 km 2 ), but not in small, warm lakes (annual air temperature more than 0.9–1.5°C). We then explored how climate change will alter coexistence by substituting climate scenarios for 2091–2100 into our model. The model predicts that brown trout will be extirpated from approximately half of the lakes where they presently coexist with pike and from nearly all 9100 lakes where pike are predicted to invade. Context dependency was critical for understanding pike–brown trout interactions, and, given the widespread occurrence of context-dependent species interactions, this aspect will probably be critical for accurately predicting climate impacts on biodiversity.

scholarly journals Individual differences in dominance-related traits drive dispersal and settlement in hatchery-reared juvenile brown trout

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jorge R. Sánchez-González ◽  
Alfredo G. Nicieza
Keyword(s):  
Body Size ◽  
Brown Trout ◽  
Environmental Conditions ◽  
Salmo Trutta ◽  
Spatial Scales ◽  
Juvenile Fish ◽  
Structured Populations ◽  
Dispersal Ability ◽  
Introduced Fish ◽  
Juvenile Brown Trout

AbstractEffective management of exploited populations is based on an understanding of population dynamics and evolutionary processes. In spatially structured populations, dispersal is a central process that ultimately can affect population growth and viability. It can be influenced by environmental conditions, individual phenotypes, and stochastic factors. However, we have a limited knowledge of the relative contribution of these components and its interactions, and which traits can be used as reliable predictors of the dispersal ability. Here, we conducted a longitudinal field experiment aimed to identify traits which can be used as proxy for dispersal in juvenile brown trout (Salmo trutta L.). We measured body size and standard metabolic rates, and estimated body shapes for 212 hatchery-reared juvenile fish that were marked with individual codes and released in a small coastal stream in northwest Spain. We registered fish positions and distances to the releasing point after 19, 41, 60 and 158 days in the stream. We detected a high autocorrelation of dispersal distances, demonstrating that most individuals settle down relatively soon and then hold stable positions over the study period. Body size and fish shape were reliable predictors of dispersal, with bigger and more robust-set individuals being more likely to settle closer to the release site than smaller and more elongated fish. In addition, the analysis of spacing and spatial patterns indicated that the dispersal of introduced fish could affect the distribution of resident conspecifics. All together, these results suggest that stocking programs aimed to the enhancement of overexploited populations at fine spatial scales can be optimized by adjusting the size and shape of the introduced fish to specific management targets and environmental conditions.

Sign in / Sign up

Export Citation Format

Share Document