Copepods as the first intermediate hosts of Ligula intestinalis L.: Parasite of bream Abramis brama L. in the Vistula Lagoon of the Baltic Sea

Abstract

Seven copepod species (potential intermediate hosts of Ligula intestinalis L.) are recorded in the Vistula Lagoon. Megacyclops viridis (Jurine) and Diacyclops bicuspidatus (Claus) are dominant species among the Cyclopoida group and may be the main potential first intermediate host of L. intestinalis. Cytopoidae is unevenly distributed in the lagoon. The parts of the lagoon with high crustacean densities and high levels of bream infestation coincide. The peaks of Cyclopoidae abundance and the highest infestation of the bream by L. intestinalis were recorded in 1998–2000. This study shows that bream infestation in the Vistula Lagoon is directly connected with the presence of freshwater copepods (the first intermediate hosts of L. intestinalis), its abundance, and its spatial distribution over the lagoon area.