The Common Creek Crab, Liberonautes latidactylus, is one of hundreds of species becoming less common in African freshwaters, according to a new assessment by the International Union for Conservation of Nature (IUCN) for its Red List of threatened species. Twenty-one percent of the 5,167 freshwater plant and animal species its scientists surveyed are threatened with extinction.

Habitat loss due to farming, deforestation, water extraction and damming is one of the main culprits, according to the IUCN. Overfishing, pollution and invasive species also threaten freshwater species with extinction. For instance, nearly half the fish in Lake Victoria – the world’s second largest freshwater lake – are threatened or already extinct because of pollution and the invasion of the Nile perch. (Cichlid fish, though, are thriving in the lake and in evolution research, according to a recent Nature feature article)

The 5-year survey was prompted by a paucity of information on the conservation status of freshwater plants and animals in Africa, however the IUCN says there are still significant gaps in surveying, particularly in northern and western Africa.

Image: Piotr Naskrecki/IUCN