poikilohydric

Poikilohydric refers to organisms whose body water content fluctuates with that of their surrounding environment. Unlike homeohydric organisms, which maintain a relatively constant internal water balance, poikilohydric organisms do not possess sophisticated mechanisms for regulating their hydration levels. Their water content is largely dependent on the availability of water in their habitat.

This characteristic is common among many plants, especially those in arid or intermittently moist environments, such as lichens, mosses, and certain algae. When conditions are dry, poikilohydric organisms can tolerate significant desiccation, entering a dormant state. Upon rehydration, they can resume metabolic activity. This ability to survive extreme water loss is often achieved through various biochemical and physiological adaptations, including the accumulation of compatible solutes that protect cellular structures from damage during drying.

Fungi also exhibit poikilohydric tendencies, particularly many saprophytic and parasitic species. Their growth and reproductive processes are closely tied to ambient moisture levels. The strategy of poikilohydry allows these organisms to colonize and survive in environments where water availability is highly variable, a significant advantage in many ecological niches. Understanding poikilohydry is crucial in fields like ecology, plant physiology, and mycology for comprehending organismal survival strategies and distribution patterns.