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. © 2016, Springer-Verlag Berlin Heidelberg.