Freshwater Crabs of Sri Lanka

Sri Lanka is situated in one of the world’s 34 "biodiversity hotspots" (Beenaerts, 2010). Despite the island’s small size (65,600 km2), its freshwater crab diversity is significantly higher than in other tropical Asian countries (Bahir et al., 2005). As of today, the country has recorded 51 species (4% of the global freshwater crab species) of freshwater crabs of the family Gecarcinucidae and 50 of which are endemic (Bahir et al., 2005; Bahir & Gabadage, 2012; Beenaerts, 2010).  Although, freshwater crabs occur at all elevations throughout the island nearly half the freshwater crabs known to date (23 species) are point endemics (Bahir & Gabadage, 2012; Beenaerts, 2010). The reason why freshwater crabs show such a highly restricted distribution is unclear (Bahir & Gabadage, 2012).  Approximately 80% of crab species (41 out of 51) are restricted to the country’s rainforested south-western ‘wet zone’, which accounts for only a quarter of Sri Lanka’s territory (Bahir …