Caecocypris basimi, the Haditha cavefish, is a species of cyprinid fish endemic to Iraq, only occurring in aquifers near Haditha. It is found in an underground sinkhole directly under a shrine the only way to access which is a well 5m below the shrine. This cavefish is the only member of its genus. The species is classed as Critically endangered, possibly extinct, by the IUCN, as there have been no records since 1983 despite a comprehensive survey in 2012. The primary threat is water extraction, which has lowered the groundwater level. It is placed as one of the top 10 lost freshwater fishes to be found.