Centromerus anoculus

Centromerus anoculus (Aranha-cavernicola-de-São-Vicente) is a critically endangered cave-dwelling spider endemic to Brazil. This small arachnid belongs to the sheet weaver family (Linyphiidae) and exhibits typical cave adaptations including reduced or absent eyes, as suggested by its scientific name "anoculus" meaning "without eyes." The species displays the pale coloration common among cave-adapted organisms and likely feeds on small invertebrates within its subterranean environment.

The spider is found exclusively in cave systems near São Vicente, in São Paulo state, Brazil. These limestone caves provide the stable temperature, high humidity, and darkness that cave-obligate species require. The species appears to have an extremely restricted range, making it particularly vulnerable to environmental changes.

The primary threat to *C. anoculus* stems from its highly limited distribution. Cave ecosystems are inherently fragile, and any disturbance to the specific cave systems where this species occurs could prove catastrophic. Potential threats include groundwater contamination, changes in hydrology, human disturbance from cave exploration or tourism, and habitat modification in surrounding surface areas that could affect cave conditions.

Current conservation measures for this species are not well-documented, reflecting the broader challenge of protecting Brazil's lesser-known endemic cave fauna. The species' critical status highlights the urgent need for systematic surveys of Brazilian cave biodiversity and implementation of protective measures for key cave systems.

The outlook for *C. anoculus* remains uncertain due to limited research and monitoring. Without comprehensive population assessments and habitat protection measures, this endemic spider faces continued risk of extinction.