Spiders in caves

World experts of different disciplines, from molecular biology to macroecology, recognize the value of cave ecosystems as ideal ecological and evolutionary laboratories. Among other subterranean taxa, spiders stand out as intriguing model organisms for their ecological role of top-predators, their unique adaptations to the hypogean medium and their sensitivity to anthropogenic disturbance.As the description of the first eyeless spider (Stalita taenaria), an array of papers on subterranean spider biology, ecology and evolution has been published, but a comprehensive review on these topics is still lacking. We provided a general overview of the spider families recorded in hypogean habitats worldwide,we reviewed the different adaptations of hypogean spiders to subterranean life, and we summarized the information gathered so far about their origin, population structure, ecology and conservation status. Finally, we pointed out the limits of the knowledge we currently have regarding hypogean spiders, aiming to stimulate future research.