Sunilkumar, Mohamed K; Dr.Diwan, A D(Cochin University of Science and Technology, June , 1989)
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Abstract:
The present investigation has been carried out to understand the process and events leading to maturation of the ovary and testis in the Indian white prawn Penaeus indicus. The study includes the classification of the ovarian maturity stages based on its colour, gonadosomatic index, oocyte diameter and morphological changes in the oocyte. Further the process of oogenesis has been investigated using light and electron microscopic techniques. A histochemical study of the ovary has also been carried out to determine the sequence in which yolk substances are synthesized or sequestered in the oocytes and also to elicit the nature of the penaeid yolk material. The process of spermatogenesis and the development of the spermatophore has been studied in detail using light and electron microscopic methods. In addition a brief histochemical study on the testis was also made to understand the nature of the organic reserves in the sperm cells.
Description:
Centre of Advanced Studies in Mariculture,
Central Marine Fisheries Research Institute
Sarita,G Bhat; Dr.Bright Singh,I S(Cochin University Of Science And Technology, May 4, 1998)
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Abstract:
Even though Bergey '5 Manual has been recognized globally as the guide to
bacterial systematics, it has to be emphasized that descriptions given to a large extent
are based on studies made with temperate isolates This leads one to conclude that
any attempt to identify the tropical isolates with identification keys and tables
generated from this information may lead to erroneous conclusions. And there is
every possibility of the existence of genotypic and phenotypic variants or even nev.
species in this part ofthe aquatic ecosystem. Applications ofa polythetic scheme of
classification based on the principles of Numerical Taxonomy opens up exciting
avenues for bringing to light, this possibility which otherwise would have been
masked by the unidirectional approach as in monothetic schemes.
Another added advantage of clustering a ‘natural’ bacterial population by
numerical taxonomy, is the ease by which genotypic characterization could be
performed on the clusters by selecting a representative from each cluster This helps
overcome the practical impossibility of analyzing all the isolates in a pani:'_lar
cluster. The genotypic characteizarion would either be mole °/o G-'rC. DNA-D.\_-X
hybridization, DNA-RNA hybridization or DNA fingerprinting. Considering the requirement creating a broad base in the understanding of the family Vibrionaceae associated with the larvae ofM rosenbergii, the present work was undertaken to channelize every new information generated for developing appropriate managerial measures to protect the larvae from vibriosis during the unusually prolonged larval phase.
Description:
School of Environmental Studies.
Cochin University of Science and Technology