Subterranean Fishes of the World

7072

2025

African Journal of Ecology

1-9

63:e70135

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2025 The Author(s)

Understanding patterns of biodiversity distribution is fundamental for ecology, biogeography, and conservation. However, persistent challenges arise from the inaccessibility of many regions and habitats. Subterranean environments, in particular, host highly distinctive and specialised faunal assemblages, yet their investigation is hindered by logistical, technical, and environmental constraints. Despite the wide range of ecosystems across the African continent, its subterranean biodiversity remains remarkably underexplored. To address this gap and provide evidence-based guidance for decision-makers and research prioritisation, we compiled and analysed records of terrestrial and aquatic cave-restricted species across Africa. Specifically, we evaluated whether accessibility to natural subterranean habitats influences scientific knowledge and perceptions of biodiversity distribution. We hypothesised that limited accessibility, resulting from natural, social, and economic barriers, constrains data collection and thereby reduces our understanding of subterranean biodiversity. Our synthesis revealed 373 cave-restricted species recorded from Africa, of which 86 (~23%) occur in terrestrial habitats and 287 (~77%) in aquatic systems. These species belong to six phyla: Arthropoda (348 species), Mollusca (18), Platyhelminthes (3), Annelida (2), Chordata (1), and Onychophora (1). The results indicate that areas located near roads and airports contain a greater number of records, reflecting the influence of accessibility on sampling intensity and species detection. Research progress on subterranean fauna in Africa is substantially limited by the inherent difficulties of accessing these environments and coping with their extreme conditions. In addition, less developed or politically unstable regions remain largely neglected. Insufficient funding and institutional support further exacerbate these knowledge gaps. Overall, this study highlights the urgent need to expand comprehensive research on subterranean biodiversity across Africa, encompassing both geographical regions and taxonomic groups. Such efforts are crucial for advancing our understanding and conservation of subterranean ecosystems, particularly in light of growing global threats such as climate change, habitat degradation, and resource exploitation

1