Sabu, A S (2003) Some aspects on ecotoxicology and Ecophysiology of shrimp Penaeus semisulcatus (De haan, 1844) to copper, Cadmium and zinc (TH 117). PhD thesis, Central Institute of Fisheires Education, Versova, Mumbai.
The thesis highlights the effect of copper, cadmium and zinc in green tiger prawn Penaeus semisu/catus, one of the penaeids occurring throughout the Indian coastal waters particularly in the Gulf of Mannar and Palk Bay. Acute toxicity bioassays were conducted for copper (Cu), cadmium (Cd) and zinc (In ). The 96 h LCso for copper, cadmium and zinc were 6.98 ppm, 2.8 ppm and 5.00 ppm respectively. The degree of toxicity of the three metals were in the order Cd > In > Cu. Based on the LCso values, two sublethal concentrations of copper (0.7 ppm and 1.4 ppm), cadmium (0.25 ppm and 0.5 ppm) and zinc (0.5 ppm and 1.00 ppm) were selected for bioaccumulation, physio-biochemical and histopathological studies. In all the lethal and sublethal exposures, blackening of the gill lamellae and exoskeleton was noticed. The accumulation of metals was pronounced in the hepatopancreas, gills, muscle, tail and carapace. The results of the study suggest that the shrimps could not regulate the accumulation of Cu. Cd and In . The bioaccumulation in the selected organsltissues was found to be dose dependent. In the physio-biochemical studies. an increase in the respiration rate was found in shrimps exposed to lethal concentrations of copper. cadmium and zinc. The biochemical components, carbohydrate, protein and lipid were found to get reduced during the various phases of metal exposure. The observed change in the proximate components is attributed to the alterations in the enzymes involved in cellular energy generation processes. inhibition of protein synthesis by the alteration in the DNA and RNA content and increases in the free fatty acid content due to changes in the synthesis and mobilization of lipids. Histopathological changes include haemocy1ic infiltration. swelling of gill lamellae. fusion of gill lamellae. lifting of lamellar epithelium. fusion and necrosis of secondary gill lamellae in gills and tissue debris, necrotic tubules, swelling and abnormal lumen in hepatopancreas. Ultrastructural changes in gills include damaged nuclear membrane. disrupted mitochondria, distorted endoplasmic reticulum. apical cell damage, and damage to mitochondrial and nuclear membrane. In hepatopancreas vacuole formation. breakage of cell membrane. swelling of nuclear membrane. condensed nucleus. aggregations in nucleus. disrupted endoplasmic reticulum and formation of electron dense bodies were the major changes.
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||ecotoxicology; Ecophysiology; shrimp; Penaeus semisulcatus; copper; Cadmium; zinc|
|Subjects:||Fish and Fisheries > Fish Toxicology|
|Divisions:||CMFRI-Cochin > Marine Capture > Crustacean Fisheries|
|Deposited By:||Dr. V Mohan|
|Deposited On:||29 Jan 2011 15:44|
|Last Modified:||21 Jan 2014 12:23|
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