Nandini Menon,N; Dr.Ravindranatha Menon,N(Cochin University of Science & Technology, April , 1997)
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Abstract:
The thesis deals with different aspects connected with the distribution and toxicity of PHC in crude oils in the aquatic environment and marine molluscs. Information has been gathered and presented on the present status of research in the field based on a thorough review of recent literature. It is seen from the literature that the resident time of PHC becomes lesser and lesser when crude oil is discharged in large quantities into the coastal waters where excess oxygenation light penetration, temperature availability and strong tidal currents persist. This results in the reduction of the onslaught of oil pollution. This probably shows that taxic insult of crude oil in tropical shores will be relatively lesser than that occurring in temperate and boreal waters. However, there is no record of major episodal oil pollution comparable in quantum and extent to that of Torrey Canyon or Amoco Cadiz which prevents a more reliable analysis on the issue. Considerable controversy exists on the method of estimation of PHC in seawater. However, Ultra-violet fluorescence spectroscopy has been widely recommended as an analytical tool for the determination of total hydrocarbons. Similarly representation of values as chrysene equivalents has been recognised as the most reliable method of Quantum representation.
Description:
Division of Marine Biology, Microbiology and Biochemistry, school of Marine Sciences, Cochin University of Science and Technology
Paul,Miriam; Dr.Ravindranatha Menon,N(Cochin University of Science & Technology, 2001)
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Abstract:
The present investigation has addressed the effects of PHC contaminated culture medium on the morphology, physiology and behaviour of shrimps. The shrimp Metapenaeus dobsoni is an important member of the crustacean animal community abounding the oil contaminated benthic regions of Cochin backwater system. Since it is known that true pollutants can disrupt the sustainability of ecosystems by its effect on species, populations and communities,a representative species was used for the study. The results discussed in this work is bound to help in understanding the ecotoxicant resistance that the animal may display under toxic conditions compared to dynamic steady-state systems in nature.
Description:
Division of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology
Sudheer, N S; Dr.Rosamma,Philip; Dr.Bright Singh,I S(Cochin University of Science and Technology., December , 2009)
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Abstract:
White spot syndrome virus (WSSV) is the deadliest virus among crustaceans
ever discovered having several unique and novel features. Recent developments in
genomics and proteomics could elucidate the molecular process involved in the
WSSV infection and the host pathogen interaction to some extent. Until now no
fool proof treatment or prophylactic measure has been made available to control
WSSV out breaks in culture system. Even though there are technologies like
application of immunostimulants, vaccines, RNAi and several antiviral natural
products none of them has been taken to the level of clinical trials. However, there
are several management options such as application of bioremediation technologies
to maintain the required environmental quality, maintenance of zero water exchange
systems coupled with application of probiotics and vaccines which on adoption
shall pave way for successful crops amidst the rapid spread of the virus. In this
context the present work was undertaken to develop a drug from mangrove plants
for protecting shrimp from WSSV.Mangroves belong to those ecosystems that are presently under the threat
of destruction, diversion and blatant attack in the name of so called
‘developmental activities’. Mangrove plants have unique ecological features as
it serves as an ecotone between marine and terrestrial ecosystem and hence
possess diversity of metabolites with diverse activities. This prompted them
being used as remedial measures for several ailments for ages. Among the
mangrove plants Ceriops tagal, belonging to the family Rhizophororaceae was in
attention for many years for isolating new metabolites such as triterpenes,
phenolic compounds, etc. Even though there were attempts to study various plant
extracts to develop anti-viral preparations their activity against WSSV was not
investigated as yet.
Description:
Dept.of Marine Biology,Microbiology and Biochemistry,Cochin University of Science and Technology
Bright Singh, I S; Rosamma, Philip; Resmy, Varghese; Manjusha, M; Mohandas, A(Elsevier, August 15, 2009)
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Abstract:
To demonstrate pathological changes due to white spot virus infection in Fenneropenaeus indicus, a batch
of hatchery bred quarantined animals was experimentally infected with the virus. Organs such as gills,
foregut, mid-gut, hindgut, nerve, eye, heart, ovary and integument were examined by light and electron
microscopy. Histopathological analyses revealed changes hitherto not reported in F. indicus such as
lesions to the internal folding of gut resulted in syncytial mass sloughed off into lumen, thickening of
hepatopancreatic connective tissue with vacuolization of tubules and necrosis of rectal pads in hindgut.
Virus replication was seen in the crystalline tract region of the compound eye and eosinophilic granules
infiltrated from its base. In the gill arch, dilation and disintegration of median blood vessel was observed.
In the nervous tissues, encapsulation and subsequent atrophy of hypertrophied nuclei of the neurosecretory
cells were found. Transmission electron microscopy showed viral replication and morphogenesis in
cells of infected tissue. De novo formed vesicles covered the capsid forming a bilayered envelop opened at
one end inside the virogenic stroma. Circular vesicles containing nuclear material was found fused with
the envelop. Subsequent thickening of the envelop resulted in the fully formed virus. In this study, a correlation
was observed between the stages of viral multiplication and the corresponding pathological
changes in the cells during the WSV infection. Accordingly, gill and foregut tissues were found highly
infected during the onset of clinical signs itself, and are proposed to be used as the tissues for routine disease
diagnosis.
Description:
Journal of Invertebrate Pathology 102 (2009) 225–232