Histopathological changes in the gills associated with Dactylogyrus spp. infestation in orange-spotted grouper, Epinephelus coioides reared in sea cages

A study was conducted to investigate the histological changes in the gills of orange-spotted grouper infested with flukes of Dactylogyrus spp. Several histological changes were observed in the gill which included complete fusion of secondary lamellae, dilatation of the venous sinus at the middle of the primary lamellae, oedema and complete loss of secondary lamellae, etc.