Studies on improved practices of prawn farming for higher production in central Kerala

The thesis entitled "Studies on improved practices of prawn farming for higher production in central Kerala" prepared by the author describes various practices prevailing in the study area in order to elucidate their relative merits. The study on semi-intensive farming at Mundapuram, Kannur was also carried out and included in the thesis for comparison.The author felt it important to make a critical study of the existing culture practices in the central Kerala, a region where it has been existing since time immemorial.Careful analysis of data accrued by the author has helped him to identify strength, weakness, opportunities and threats confronting the shrimp farming. As a result it was possible to evolve an appropriate management technology taking into consideration the various ecological (location specific), social and economical conditions prevalent in the vast study area.

Haematology of Fenneropenaeus indicus in response to environmental alterations and microbial infections

Aquaculture has developed to become one of the fastest growing food producing sectors in the world.Today India is one among the major shrimp producing countries in the world.There are extensive and intensive shrimp culture practices. In extensive shrimp culture, shrimps are stocked at low densities (< 25 PLs m'2)in large ponds or tidal enclosures in which little or no management is exercised or possible. Farmers depend almost entirely on natural conditions in extensive cultures. Intensive shrimp culture is carried out in high densities (>200 PLs m'2). Much of the world shrimp production still comes from extensive culture.There is a growing demand for fish and marine products for human and animal consumption. This demand has led to rapid growth of aquaculture, which some times has been accompanied by ecological impacts and economic loss due to diseases. The expansion of shrimp culture always accompanies local environmental degradation and occurrence of diseases.Disease out breaks is recognised as a significant constraint to aquaculture production. Environmental factors, water quality, pollution due to effluent discharge and pathogenic invasion due to vertical and horizontal transmission are the main causes of shrimp disease out breaks. Nutritional imbalance, toxicant and other pollutants also account for the onset of diseases. pathogens include viruses, bacteria, fungi and parasites.Viruses are the most economically significant pathogens of the cultured shrimps world wide. Disease control in shrimp aquaculture should focus first on preventive measures for eliminating disease promoting factors.ln order to design prophylactic and proactive measures against shrimp diseases, it is mandatory to understand the immune make up of the cultivable species, its optimum culture conditions and the physico chemical parameters of the rearing environment. It has been proven beyond doubt that disease is an end result of complex interaction of environment, pathogen and the host animal. The aquatic environment is abounded with infectious microbes.The transmission of disease in this environment is extremely easy, especially under dense, culture conditions. Therefore, a better understanding of the immune responses of the cultured animal in relation to its environmental alterations and microbial invasions is essential indevising strategic measures against aquaculture loss due to diseases. This study accentuate the importance of proper and regular health monitoring in shrimps employing the most appropriate haematological biomarkers for application of suitable prophylactic measures in order to avoid serious health hazards in shrimp culture systems.

Studies on the physiology of moulting in the penaeid prawn, penaeius indicius h. Milne edwards

Penaeid prawns form the most economically significant group in the marine and brackishwater fishery resources of India. This particular group contributes about 62% of the total prawn landings of the country. At present prawns have assumed an important place especially as a commodity supporting an export trade of sizable magnitude. Considerable interest has been shown in the last decade to increase prawn production through various culture practices, mainly due to the high demand for good quality prawns for export coupled with the stagnant and even depleting nature of marine catches. Available informations suggest that among the 15 species of shrimps and prawns occurring in Indian waters, which are deemed suitable for aquaculture, the Indian white prawn §.indicus is identified as one of the most important commercial species. Considering the increasing importance as an accepted species for prawn culture, £.indicus was selected for the present study. In the life history of prawns, moulting is an important event, which enables the animal to achieve growth. This dynamic physiological event continues through out the life span ofthe prawn, linking almost all biological activities with this process. Hence, a good knowledge pertaining to the physiology of moulting is imperative to understand the growth process. This knowledge will be of great use in the scientific prawn farming, so as to achieve high prawn production.

Studies On The Biology Of The Clam Sunetta Scripta (Linne), From The Subtidal Waters Of Cochin

Enhancement and culture of bivalves presents an opportunity to maximise and even increase production of many growing areas. Clam culture is less intensive both for capital and labour, involves simple farming and management techniques and is considered an efficient means of protein production. Clams are efficient converters of primary production and growth rate is fast with maximum production in 5-6 months. with culture, production is less influenced by poor recruitment. Stable production facilitates market development. Rivalves are being increasingly used in bio-medical research. Culture practices would ensure uninterrupted supplies of experimental material. Paucity of biological data restricts the development of efficient management and culture techniques of bivalves. This study was undertaken with a view to provide information on some aspects of biology of the bivalve S_. scripta which have hitherto been uninvestigated.

Generation of Variability for Salt Tolerance in Rice Using Tissue Culture Techniques

The study deals with the generation of variability for salt tolerance in rice using tissue culture techniques. Rice is the staple food of more than half of the world’s population. The management of drought, salinity and acidity in soils are all energy intensive agricultural practices. The Genetic variability is the basis of crop improvement. Somaclonal and androclonal variation can be effectively used for this purpose. In the present study, eight isozymes were studied and esterase and isocitric dehydrogenase was found to have varietal specific, developmental stage specific and stress specific banding pattern in rice. Under salt stress thickness of bands and enzyme activity showed changes. Pokkali, a moderately salt tolerant variety, had a specific band 7, which was present only in this variety and showed slight changes under stress. This band was faint in tillering and flowering stage .Based on the results obtained in the present study it is suggested that esterase could possibly be used as an isozyme marker for salt tolerance in rice. Varietal differences and stage specific variations could be detected using esterase and isocitric dehydrogenase . Moreover somaclonal and androclonal variation could be effectively detected using isozyme markers.

A Study of the impact of ISO 9001:2000 on Quality Management Practices in Selected Organisations in Kerala

The research work which was carried out to study the impact of ISO 9001: 2000, in selected organisations in Kerala, spread over various types of activities, such as fabrication of aero space hardware, glass ware, construction industries, health care units etc, encompassing, government and private enterprises, public sector undertakings, small and medium scale industries and research and development establishments. The ambience, work culture and collaboration prevalent in these organisations were varying on account of the environment in which they have been working. Fifty percent of the organizations selected for the study had obtained the ISO 900 I: 2000-certification since seven years or more. The process of study undertaken could invoke interest in the respondents, when a brief explanation on the purpose and need of the study was given to them prior to conducting the survey. There has been total cooperation from the management and the employees of all the organisations for the conduct of the study. Personal discussions were held with the senior management to draw their total support and involvement for the study.

Carbon/Nitrogen Ratio Optimization and Periphyton Development on the Production and Sustainability of Penaeus Monodon(Fabricius)in Extensive Culture System

Controlling the inorganic nitrogen by manipulating carbon / nitrogen ratio is a method gaining importance in aquaculture systems. Nitrogen control is induced by feeding bacteria with carbohydrates and through the subsequent uptake of nitrogen from the water for the synthesis of microbial proteins. The relationship between addition of carbohydrates, reduction of ammonium and the production of microbial protein depends on the microbial conversion coefficient. The carbon / nitrogen ratio in the microbial biomass is related to the carbon contents of the added material. The addition of carbonaceous substrate was found to reduce inorganic nitrogen in shrimp culture ponds and the resultant microbial proteins are taken up by shrimps. Thus, part of the feed protein is replaced and feeding costs are reduced in culture systems.The use of various locally available substrates for periphyton based aquaculture practices increases production and profitability .However, these techniques for extensive shrimp farming have not so far been evaluated. Moreover, an evaluation of artificial substrates together with carbohydrate source based farming system in reducing inorganic nitrogen production in culture systems has not yet been carried-out. Furthermore, variations in water and soil quality, periphyton production and shrimp production of the whole system have also not been determined so-far.This thesis starts with a general introduction , a brief review of the most relevant literature, results of various experiments and concludes with a summary (Chapter — 9). The chapters are organised conforming to the objectives of the present study. The major objectives of this thesis are, to improve the sustainability of shrimp farming by carbohydrate addition and periphyton substrate based shrimp production and to improve the nutrient utilisation in aquaculture systems.

Studies on the bacteria associated with Penaeus indicus in a culture system

Ocean persists as a rich and renewable source of cheap protein for the whole world. Among the prawns/shrimps landed from the Indian Ocean and her backwaters, more than 90% are exported to affluent countries. The Indian white prawn Penaeus indicus, constitutes the major portion of the frozen shrimps exported from India every year. The present study is aimed at gathering information on the total heterotrophic bacteria (THB) associated with B. indicus, with special reference to eggs, nauplii, zoeae, mysis, and post larvae in hatchery, and juveniles and adults in culture pond. Simultaneously, IHB associated with E. indicus in its natural habitat also is studied for comparison. It is envisaged that this information will be highly useful for modifying the existing hatchery and pond management-practices.