Dynamics of thermal tolerance plasticity across fish species and life stages.

Climate warming with associated heat waves presents a concerning challenge for ectotherms such as fishes. During heatwaves, the ability to rapidly acclimate can be crucial for survival. However, surprisingly little is known about how different species and life stages vary in their acclimation dynamics, including the magnitude of change in thermal tolerance through acclimation (i.

Global change and premature hatching of aquatic embryos.

Anthropogenically induced changes to the natural world are increasingly exposing organisms to stimuli and stress beyond that to which they are adapted. In aquatic systems, it is thought that certain life stages are more vulnerable than others, with embryos being flagged as highly susceptible to environmental stressors. Interestingly, evidence from across a wide range of taxa suggests that aquatic embryos can hatch prematurely, potentially as an adaptive response to external stressors, despite the potential for individual costs linked with underdeveloped behavioural and/or physiological functions.

Acute warming tolerance (CT) in zebrafish () appears unaffected by changes in water salinity.

Tolerance against acute warming is an essential trait that can determine how organisms cope during heat waves, yet the mechanisms underlying it remain elusive. Water salinity has previously been suggested to modulate warming tolerance in fish and may therefore provide clues towards these limiting mechanisms. Here, using the critical thermal maximum (CT) test, we investigated whether short (2 hours) and long (10 days) term exposure to different water salinities (2 hours: 0-5 ppt, 10 days: 0-3 ppt) affected acute warming tolerance in zebrafish ( = 263).

The OptoReg system: a simple and inexpensive solution for regulating water oxygen.

This paper describes an optocoupler-based regulation apparatus for saturation manipulation of oxygen in water (OptoReg). This system enables control of solenoid valves for oxygen and nitrogen gases using a FireSting-O meter, an optocoupler box and an electronic switch box. The hardware components connect to a computer through Universal Serial Bus (USB) cables.

A novel method for measuring acute thermal tolerance in fish embryos.

Aquatic ectotherms are vulnerable to thermal stress, with embryos predicted to be more sensitive than juveniles and adults. When examining the vulnerability of species and life stages to warming, comparable methodology must be used to obtain robust conclusions. Critical thermal methodology is commonly used to characterize acute thermal tolerances in fishes, with critical thermal maximum (CT) referring to the acute upper thermal tolerance limit.