Ultrastructural alteration in Gill and Hepatopancrease of freshwater prawn Macrobrachium rosenbergii exposed to Co gamma radiation.

The present study was designed to evaluate the impact of gamma radiation (Co) on freshwater prawn Macrobrachium rosenbergii by using electron microscopic (SEM, TEM) studies. One set of prawns (experimental group) was irradiated (3, 30, 300, and 3000 mGy) by Theratron Phoenix TeleCobalt Unit [P-33], while other set of prawns (control group) was maintained (non-irradiated) separately. Scanning electron microscopic observations of gills and hepatopancreas showed fused and swollen lamella, abnormal gill tips, wrinkled lamellar epithelium, and necrotic epithelium surface in irradiated groups, while no such abnormalities were obvious in the control group. Transmission electron microscopic studies showed damaged nucleus, granulated mitochondria, vacuoles with crystalline granular inclusions, destructed membrane, vacuoles filled with granules, rough endoplasmic reticulum with residual bodies, shrunken mitochondria, dilated rough endoplasmic reticulum, and dilated cisternae of the Golgi body in irradiated groups. The structural abnormalities of vital organs could affect physiological functions such as respiration, osmo-ionic regulation and storage, secretion of the gills, and hepatopancreas, which in turn could adversely affect the growth and survivability of M. rosenbergii.