The West African pygmy herring (Sierrathrissa leonensis) is a very small fish, reaching a maximum length of 3 centimetres (1.2 in) SL.

[2] It is a member of the clupeiform family Dorosomatidae in the freshwater systems of western and central Africa that includes such species as the Microthrissa royauxi of the Congo River basin and Limnothrissa miodon of Lake Tanganyika.

It schools in open waters and to a maximum depth of around 2 to 8 m (6.6 to 26.2 ft); rising to about 30 cm (12 in) from the surface at night in Lake Volta.

[2] As the West African pygmy herring has a widespread distribution and is short lived with high resilience to exploitation, it is therefore listed as Least Concern.

[1] The West African pygmy herring was first described from Sierra Leone, but this was somewhat controversial and claims were made that the specimens were nothing more than the unmetamorphosed larva of a species of Pellonula or of Cynothrissa.