Coregonus albula, known as thevendace or as theLeast cisco,[1] is a species offreshwater whitefish in the familySalmonidae. It is found in lakes in northern Europe, especially Finland, Latvia,[2] Lithuania, Sweden, Russia and Estonia, and in some lakes of Norway, the United Kingdom, northern Germany, and Poland. It is also found in dilutedbrackish water in the Gulfs ofFinland andBothnia, both of which are in theBaltic Sea.[3]
The length of an adult is normally about 20 cm (8 in). The maximum age is about ten years.[3]
Fried vendace is a popular summertime food in Finland.
The vendace is traditionally the most important target of freshwater fisheries in parts ofFennoscandia and Russia. Vendaceroe is considered a delicacy, which has been granted aPDO status in the SwedishBothnian Bay archipelago (Kalix löjrom).
The vendace is a slim and streamlined fish with anadipose fin - an additional small fin on the back between thedorsal fin and the tail (caudal fin) which is typical in the salmon family. Its lower jaw is longer than the upper one. It is similar in appearance to both thecommon whitefish (Coregonus lavaretus sensu lato), whose upper jaw is longer than its lower one, and thepeled (Coregonus peled), whose jaws are of equal length. The back is bluish green or brown, the flanks are silvery and the belly white. This fish seldom grows more than 30 cm (12 in) long.[4]
Vendace mainly feed on zooplankton, such as smallcrustaceans and their larvae, but larger fish also feed on floating insects andfish fry. The fish live in schools made up of large groups of individuals. They lay their eggs on pebbly or sandy ground, some in shallow water and others at depths of down to 20 m (66 ft). The fish mature at a young age and most spawn for the first time in their second year, but a few may breed in their first autumn.[4]
Finns fishing vendace withseine onPuruvesi lake in Finland in February 1964
The European vendace is very closely related to the SiberianCoregonus sardinella (sardine cisco) and also toC. peled, although phenotypic differences are clear.[5]
Within the vendace, taxonomic subdivisions have been suggested both on geographical grounds and between sympatric ecotypes.FishBase lists the British populations of vendace as a separate species,Coregonus vandesius,[6] but this distinction is not accepted by all scientists.[7]
Coregonus albula generally breeds in the autumn, but in several North European lakes distinct spring-spawning populations of vendace exist, some of which have been described as separate species: in Sweden, asCoregonus trybomi, and in two lakes of northern Germany, asCoregonus fontanae andCoregonus lucinensis. These populations are sympatric with autumn-spawning vendace and seem to have evolved post-glacially from them independently in each lake.[8][9]
Seven vendaces in the coat of arms ofViitasaari in Finland