Table 1. Degree tissue changes (DTC)* according to stages of lesions observed in liver and gill.
| Liver | Stages |
|---|---|
| Hemorrhage/hyperemia/congestion/edema sinusoidal/perivascular | 1 |
| Cellular tumefaction/hydropic degeneration | 1 |
| Cytoplasmic inclusion/hyaline/lipofuscin | 1 |
| Melanomacrophages deposits | 1 |
| Cell atrophy/hypertrophy | 2 |
| Nuclear alterations (pyknosis/karyolysis/karyorrhexis/inclusions) | 2 |
| Granulocytic or agranulocytic infiltrate | 2 |
| Cell necrosis (focal/diffuse) | 3 |
| Sinusoidal epithelial necrosis | 3 |
| Gill | |
| Hypertrophy of lamellar epithelium | 1 |
| Hyperplasia of lamellar epithelium | 1 |
| Fusion of lamelar epithelium | 1 |
| Mucous cell proliferation | 1 |
| Edema of epithelial cell | 1 |
| Shortening of secondary lamella | 1 |
| Lamellar atrophy | 1 |
| Adherence of lamelar epithelium | 1 |
| Mucous cell hyperplasia and hypertrophy | 1 |
| Epithelial lifting | 1 |
| Vasodilatation and vascular hyperemia | 1 |
| Leukocyte infiltrate | 1 |
| Telangiectasis (aneurysm) | 1 |
| Rupture of lamelar epithelium | 2 |
| Lamellar thrombosis | 2 |
| Epithelial fibrosis | 3 |
| Fibrous lamellar thrombosis | 3 |
| Necrosis | 3 |
Notes.
*
According to Bernet et al. (2001); 1, easily reversible; 2, moderated alterations with probable reversion after end of exposure and 3, irreversible alterations.