Lost and found: how a single clue led to the rediscovery of a crab not seen for 225 years

The label on a specimen of Afzelius's crab simply said Sierra Leone'. But it was enough for an expedition to track it down along with another lost' freshwater crab

Tracking down rare species believed to be extinct is never easy, but when Pierre A Mvogo Ndongo travelled to Sierra Leone in January 2021 to search for lost" species of land-dwelling crabs, the feeling of looking for a needle in a haystack was particularly powerful due to the size of the haystack". For one of the species, Afzelius's crab (Afrithelphusa afzelii), last seen in 1796, the only clue was the label on a specimen that simply said: Sierra Leone."

Mvogo Ndongo's expedition was primarily looking for the rainbow-coloured, land-dwelling Sierra Leone crab Afrithelphusa leonensis, lost to science for 65 years and thought to be possibly extinct - one of the species on wildlife charity Re:wild's 25 most wanted lost species" list. He also hoped - but never expected - to find, Afzelius's crab (Afrithelphusa afzelii).