An eimerid apicomplexan causing pathology in wild and farmed lumpfish, Cyclopterus lumpus

Due to an increasing demand for lumpfish, Cyclopterus lumpus, as a biological control against sea

lice in Atlantic salmon farms, infectious agents infecting lumpfish have lately received considerable

attention. Here we report an eimerid apicomplexan from farmed juveniles in Norway and

wild-caught broodfish from Iceland. It infects the intestinal tract, causing clinical signs and severe

histopathology. Both merogonic and gamogonic stages were detected, suggesting a monoxenous

life cycle, but no mature oocysts were observed. Therefore, further research is needed to establish

its generic identity and to fully understand the potential negative impact this apicomplexan has to

the aquaculture industry.