Interindividual behavioural variation in response to elevated CO predicts mRNA transcript abundance of genes related to acid-base regulation in medaka (Oryzias latipes).

Rising carbon dioxide (CO) in aquatic ecosystems due to climate change is a challenge for aquatic ectotherms. We examined whether interindividual variation in behavioural responses to CO could predict how a teleost fish would respond to elevated CO for multiple phenotypic and molecular traits. To this end, we first quantified behavioural responses of individuals exposed to acute elevated CO, and used these to assign individuals as either high or low responders relative to the population mean.

Non-Lethal Sampling Supports Integrative Movement Research in Freshwater Fish.

Freshwater ecosystems and fishes are enormous resources for human uses and biodiversity worldwide. However, anthropogenic climate change and factors such as dams and environmental contaminants threaten these freshwater systems. One way that researchers can address conservation issues in freshwater fishes is integrative non-lethal movement research.

Molecular and physiological responses predict acclimation limits in juvenile brook trout (Salvelinus fontinalis).

Understanding the resilience of ectotherms to high temperatures is essential because of the influence of climate change on aquatic ecosystems. The ability of species to acclimate to high temperatures may determine whether populations can persist in their native ranges. We examined physiological and molecular responses of juvenile brook trout (Salvelinus fontinalis) to six acclimation temperatures (5, 10, 15, 20, 23 and 25°C) that span the thermal distribution of the species to predict acclimation limits.

Sub-lethal temperature thresholds indicate acclimation and physiological limits in brook trout Salvelinus fontinalis.

The upper thermal tolerance of brook trout Salvelinus fontinalis was estimated using critical thermal maxima (CT ) experiments on fish acclimated to temperatures that span the species' thermal range (5-25°C). The CT increased with acclimation temperature but plateaued in fish acclimated to 20, 23 and 25°C. Plasma lactate was highest, and the hepato-somatic index (I ) was lowest at 23 and 25°C, which suggests additional metabolic costs at those acclimation temperatures.