Aniladevi Kunjamma, K P; Dr. Babu, Philip(Cochin University of Science and Technology, April , 2008)
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Abstract:
Man uses a variety of synthetic material for his comfortable materialistic
life. Thus human interactions may become harmful for various terrestrial and aquatic
lives. This is by contaminating their habitat and by becoming a threat to organisms
itself. Thus the application and dispersal of several organic pollutants can lead to the
development of several mutated forms of the species when exposed to sublethal
concentrations of the pollutants. Otherwise, a decrease in number or extinction of
these exposed species from earth's face may happen. Pesticides, we use for the
benefit of crop yield, but its persistence may become havoc to non-target organism.
Pesticides reaching a reservoir can subsequently enter the higher trophic levels.
Organophosphorus compounds have replaced all other pesticides, due to its acute
toxicity and non-persistent nature.Hence the present study has concentrated on the toxicity of the largest
market-selling and multipurpose pesticide, chlorpyrifos on the commonly edible
aquatic organism, fish. The euryhaline cichlid Oreochromis mossambicus was
selected as animal model. The study has concentrated on investigating biochemical
parameters like tissue-specific enzymes, antioxidant and lipid-peroxidation
parameters, haematological and histological observations and pesticide residue
analysis.Major findings of this work have indicated the possibility of aquatic toxicity
to the fish on exposure to the insecticide chlorpyrifos. The insecticide was found as
effective to induce structural alteration, depletion in protein content, decrease in
different metabolic enzyme levels and to progress lipid peroxidation on a prolonged
exposure of 21 days. The ion-transport mechanism was found to be adversely
affected. Electrophoretic analysis revealed the disappearance of several protein bands
after 21days of exposure to chlorpyrifos. Residue, analysis by gas chromatography
explored the levels of chlorpyrifos retaining on the edible tissue portions during
exposure period of 21days and also on a recovery period of 10 days.
Description:
Department of Marine Biology, Microbiology and Biochemistry, Cochin
University of Science and Technology.
Hari Sankar, H S; Babu,Philip(Cochin University of Science and Technology, December 30, 2013)
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Abstract:
The major digestive enzyme activities and digestive indices were compared between
Etroplus suratensis and Oreochromis mossambicus. Pepsin - like acid proteases that acts on low pH has been identified all along the digestive tract of both the fishes. Comparatively low alpha amylase activity is shown by the E. suratensis and the enzyme is distributed almost equally throughout the intestinal segments in both the species. Very low alkaline protease activity is found in the stomach of both the
fishes and in O. mossambicus, the enzyme activity diminishes extensively towards the posterior portion of the intestine whereas in E. suratensis the activity increases towards the posterior part. The present study showed that lipase is one of the prominent digestive enzymes in O. mossambicus with a remarkable specific activity throughout the digestive tract than that of E. suratensis .It has been noted that O. mossambicus has a higher values for digestive somatic index, hepato somatic index, intestinal coefficient and gut Vs standard length ratio than that of E. suratensis indicating its higher digestive and metabolic capabilities. The early maturity and fast growth of O. mossambicus can be explained by their enhanced digestive indices. The compa ratively low activities of acid protease, amylase, lipase and total alkaline protease of E. suratensis revealed poor digestive capacity than that of O. mossambicus