THE HISTOPATHOLOGICAL AND ULTRASTRUCTURAL ANALYSIS OF MICROSPORIDIAN INFECTION IN CATLA (CATLA CATLA) AND THEIR EFFECTS ON ANTIOXIDANT ENZYMES AND PROTEIN EXPRESSION

The microsporidian infection has been detected in catla and catla fry. The sporophorous vesicles, necrosis and liquefaction of muscles; as well as hypertrophy, hyperplasia and necrosis in gills and liver were observed. In the ultrathin muscle section, ellipsoidal (1.95 × 2.12 ?m) spore with anchoring disc, protuberant area and basal vacuole; and oval merronts (3.2 × 3.1 ?m), bounded by the membrane stakes with interrupted pores were observed. In the gill epithelia, disrupted organelles, tubular structures, coated vesicles and round spores (1.43 × 1.47 ?m) in direct contact with cytoplasm were found in TEM. The microsporidia appear to belong to Pleistophora species. The significant changes in antioxidant enzyme activities in liver in infected catla, indicates activation of defense mechanism. The water analysis showed high level of ammonia, COD and alkalinity. The heavy metal contents and the level of indicators microorganisms were found to be low in pond during infection. The protein analysis indicated expression of new proteins in muscle, gill and liver in infected catla. The black spot region of catla fry has shown large number of spores; and the TEM analysis revealed the presence of spores in muscle (0.41 × 0.58 ?m) and defense cells (0.28 × 0.39 ?m).