Figure 3. a. Gill from a control group showing apparently normal gill filament and gill lamellae.
b. There is severe congestion (C) of the blood capillaries; necrosis (N) thickening (T) of the gill filament, disorganization of the gill lamella.
c. Loss of gill lamellae (arrow); the covering epithelium of the operculum is markedly separated from the central cartilaginous core by sparse amounts of loose connective tissues. Mag. x400