stenotherms

Stenotherms are organisms that can tolerate only a narrow range of temperatures. This term is often contrasted with eurytherms, which can withstand a wide range of temperatures. The physiological mechanisms that limit a stenotherm's temperature tolerance are diverse and can include temperature-dependent enzyme activity, membrane fluidity, and metabolic rates. For example, many enzymes crucial for life processes function optimally within a specific temperature band. Outside this range, their shape may change, rendering them ineffective, or they may denature completely.

Stenothermic organisms are often found in environments with stable temperatures, such as deep ocean waters or certain tropical regions. In these habitats, the selective pressure for a broad temperature tolerance may be less pronounced. Conversely, organisms living in environments with significant temperature fluctuations, like intertidal zones or temperate regions with distinct seasons, are more likely to be eurythermic. The ability to survive a narrow temperature range can be a significant disadvantage if the environment's temperature shifts beyond the organism's physiological limits, potentially leading to stress, reduced reproductive success, or death. Climate change, which is causing global temperature increases, poses a particular threat to stenothermic species as their specialized environments may become unsuitable.