Leucism in the European sardine Sardina pilchardus (Clupeidae)

The first case of abnormal leucism in the European Sardine or Pilchard Sardina pilchardus (Walbaum, 1792) is reported. A few sardines with abnormal pigmentation were captured by fishermen in the northern part of the Gulf of Cadiz (SW Atlantic coast), between Portugal and Spain, and one specimen was presented to the authors for examination. Species identification was verified using both morphological and genetic criteria. Despite the relative abundance of sardines along the Atlantic coast of the Iberian Peninsula, the current specimen represents the first known case of leucism in S. pilchardus. The observed colour aberration may have been caused by either heavy metal pollutants and/or a high level of endogamy in this heavily exploited local sardine stock.Financial support was given by CSIC through Intramural Research program 2018 under grant 201830I081 to EGO.Peer reviewe