speleobiology

Speleobiology is the study of the biology of organisms that inhabit caves and other subterranean environments. It investigates how life persists in darkness, low nutrient flux, stable microclimates, and humidity, and how prolonged isolation can drive distinctive adaptations and diversification. The field encompasses a wide range of life, from macrofauna such as troglobiont insects, amphibia, and fish to microfauna including bacteria, archaea, fungi, and microbial mats.

Organisms in caves are categorized by their ecological strategies: troglobionts are obligate cave dwellers whose life cycles occur entirely underground; troglophiles can complete life cycles in caves but also survive on the surface; and trogloxenes regularly use caves but depend on surface habitats for part of their life cycle. Cave ecosystems derive energy from surface-derived organic matter or from in situ chemoautotrophic microbial processes, such as sulfur- or iron-oxidizing microbial communities that support food webs in the absence of light.

Research methods in speleobiology include careful field observation and sampling under safety constraints, environmental DNA analysis, metabarcoding, genomics, isotopic and microelectrode measurements of cave chemistry, and long-term ecological monitoring. Ethical considerations and conservation are important due to the fragility of subterranean habitats and their specialized biota.

Notable examples include the olm (Proteus anguinus) in Europe, the Mexican blind cavefish (Astyanax mexicanus) with surface and cave forms, and various troglobitic invertebrates and cave-adapted bats. Speleobiology intersects with geology, hydrology, microbiology, and evolutionary biology, contributing to biodiversity science, conservation, and understanding life in extreme environments.

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