West African pygmy herring

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Sierrathrissa leonensis
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Clupeiformes
Family: Clupeidae
Genus: Sierrathrissa
Species: S. leonensis[1]
Binomial name
Sierrathrissa leonensis[1]
Thys van den Audenaerde, 1969

The West African pygmy herring (Sierrathrissa leonensis) is a very small fish, reaching a maximum length of 3 centimetres (1.2 in) SL, is a member of the herring family Clupeidae, and belongs to a radiation of the subfamily Pellonulinae 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 is the only species of its genus.[1]

Description[edit]

A very small fish which shows a reduction in size and some neoteny when compared to its larger relatives.[2]

Habitat and ecology[edit]

The West African pygmy herring is found in rivers and man-made lakes. 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. It feeds on plankton, especially cladocerans.[1]

Distribution[edit]

The West African pygmy herring has a widespread but patchy distribution from Senegal to Cameroon. In west Africa it occurs in Senegal River, Gambia River, Bia River, Niger River basin and Wouri River, as well as the man made Lake Volta and Lake Kainji.[3] This speciies is native to Cameroon, Ivory Coast, Ghana, Nigeria, Gambia, Senegal and Sierra Leone.[1]

Fisheries and conservation[edit]

As the West African pygmy herring has a widespread distribution and it is short lived wth high resilience to exploitation, it is therefore listed as Least Concern. In Nigeria this species is subject to some commercial fishing for human consumption.[3]

Taxonomy[edit]

The West African pygmy herring was first described from Sierra Leone buth 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 Cyanothrissa. However, when fully mature specimens of Sierrathrissa were described at 21-28mm SL it was clear that these were not juveniloes of other species.[2]

References[edit]