2.3. Histopathological study
Fungi infected moribund shrimps were injected with Davidson's fixative in the heapatopancreases and muscle of shrimp in order to avoid autolysis.
After injection, the whole shrimp was immersed with the same fixative for 48 h before processing. The black gill infected
portions of gills were dissected and immersed in Davidson's fixative for 48 h and transferred to 70% ethanol for further processing. Further, the sections were stained with usual Ehrlich's haematoxylin and eosin stains, the slides were observed under a 40× lens in light microscope (Olympus) for routine histopathological investigation to determine the internal lesions in the shrimps due to fungal invasion.