A Comprehensive Review of Earthworm Diversity in India

Earthworms are vital soil invertebrates that function as ecosystem engineers by regulating soil structure, nutrient cycling, and organic matter decomposition. Their ecological activities significantly influence soil fertility and agricultural sustainability, particularly in tropical and temperate regions. Although India supports substantial earthworm diversity, systematic and region-specific assessments remain uneven. Available studies indicate strong spatial variation in earthworm diversity across Indian states, influenced by climate, soil characteristics, and land-use patterns. Cosmopolitan species such as Metaphire posthuma are widely distributed, while regional and endemic taxa remain poorly documented. In India, current research identifies a diverse fauna comprising approximately 505 species and subspecies across 10 families and 67 genera. Notably, earthworm diversity in Maharashtra has received limited scientific attention despite its diverse agro-ecological settings. This review synthesizes existing literature on earthworm diversity in India, highlights their ecological significance, and identifies major research gaps. The study emphasizes the need for comprehensive biodiversity assessments and conservation-oriented soil management strategies, particularly in underexplored regions. This literature review indicates a significant disparity in earthworm diversity across different Indian regions. The Western Ghat biodiversity hotspot exhibits the highest species richness with 271 recorded species, followed by Kerala with 28 species. In contrast, the lowest diversity is observed in Gujarat, where only 4 species have been identified. These findings highlight that the Western Ghat remain a critical zone for earthworm abundance and taxonomic variety compared to other geographical regions