stenotopic

Stenotopic is an adjective used in ecology and biology to describe organisms that have a narrow tolerance range for one or more environmental factors. The term derives from Greek stenos “narrow” and topos “place.” Stenotopic species are highly specialized and restricted in their geographic distribution because their survival depends on relatively constant conditions such as temperature, salinity, pH, or habitat structure. They are contrasted with eurytopic organisms, which can cope with broad variations in environmental factors.

In aquatic systems, stenotopic organisms may be stenothermal (narrow temperature tolerance) or stenohaline (narrow salinity tolerance). For example, many reef-associated invertebrates and some freshwater species show narrow tolerances and are vulnerable to climate fluctuations, pollution, or habitat disturbance that alter their precise environmental regime. Terrestrial stenotopes may rely on microclimates or specific habitat features, such as stable humidity in shaded understories or the steady conditions of limestone caves.

The concept is widely used in conservation biology to assess vulnerability to environmental change: stenotopic species can be at higher risk due to narrow ecological niches and limited dispersal, making them more sensitive to habitat loss and climate shifts. By contrast, generalist or eurytopic species often persist across broader geographic ranges and varied habitats. The term underscores niche specialization as a key factor shaping distribution, ecology, and responses to habitat fragmentation and climate change.