The ballan wrasse, Labrus bergylta (Labridae),
is a protogynous hermaphrodite fish common in the
north-eastern Atlantic from Norway to Morocco. It is a
commercially important resource for local fisheries and is
currently being used as cleaner fish to control sea lice in
salmon farms in northern Europe. Two distinct colour patterns
have been recently reported in the literature: plain and
spotted. These individuals follow strikingly different life
history strategies raising the question of whether they represent
one or two independent taxonomic units. Analyses
of mitochondrial (18S, COI and control region) and nuclear
(S7) markers revealed no genetic differences between these
morphotypes. Alternative explanations for the origin and
persistence of distinct morphotypes are discussed.Fundação para a Ciência e a Tecnologia (FCT); European Commissio
