Vijayan, K K; Dr.Diwan, A D(Cochin University of Science And Technology, November , 1988)
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Abstract:
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.
Description:
School of marine sciences, Central institute of fisheries technology, Cochin University of Science And Technology
Gopalakrishnan,T C; Dr.Kurian, C V(Cochin University of Science and Technology, June , 1982)
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Abstract:
The main purpose of the Study is to outline the main distributional features of the species of the calonoid copepod family seolecithricidae in the Indian Ocean Expedition collections and to distinguish and describe their niches. In the present thesis 27 species belonging to 7 genera were identified of which 2 were new records from the Indian Ocean and one was described as a new species. In addition to the general treatment of the taxonomy, zoogeography and species diversity in relation to various environmental parameters are also attempted
Jugnu, R; Kripa, V(Cochin University of Science and Technology, January , 2006)
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Abstract:
Algal blooms are naturally occurring phenomena in the aquatic environment. These blooms cause mass mortalities of wild and farmed fish and shellfish, human intoxications which sometimes result in death, alteration of marine trophic structure through adverse effects on larvae and other life history stages of commercially important species and death of marine animals. Occurrences of harmful algal blooms and associated mortality have been reported along the coastal waters of India since the early period of the last century. The present study was taken up to study the dynamics of major phytoplankton blooms, which occur along the Kerala coast. The results of quantitative and qualitative analysis of phytoplankton in the coastal waters of Vizhinjam and Chombala, their species diversity and community structure is presented and the major algal blooms recorded along the coast of Kerala during the study period is described and their occurrence is related to the hydrographic and meteorological variations. There is a clear evident from these works in the Indian region that the fishes avoid areas where these harmful algae bloom, either due to the toxicity or due to some irritant property of the chemicals secreted by the algae. Taxonomic diversity studies indicated a change in the community structure of commercial finfishes, crustaceans and molluscs due to the bloom of C.marina and funnel plots indicated the deviation in taxonomic distinctness during the bloom period from theoretical mean for the region.
Ramachandran Nair, P V(Cochin University of Science and Technology, May , 1974)
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Abstract:
This thesis deals with the results of investigations on primary production and related aspects conducted in the Indian seas since 1957 and includes the regional and seasonal variations in the rate of production factors controlling the same and the magnitude of potential fishery resources derived from it. Data collected for various periods using oxygen and 14c techniques from the Gulf of Mannar, palk bay, the south west coast of India including laccadive sea together with other available data form the basis of these studies.
Ramachandran, A; Dr.Ranganathan, N(Cochin University of Science And Technology, September , 1988)
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Abstract:
Kerala was the pioneer in modern seafood processing and
exporting. But now the industry is Iacingalot of problems due to
low productivity and deterioration in the quality of the products.
only about 17% of the installed freezing capacity in sea food
processing industry was reported to be utilised during 1979-80.
The price of the export commodities its decided by the buyers
based on international supply and demand pattern and based on
the strength and weakness of dollar/yen. The only way to increase
the profitability of the processors is to reduce the cost of
production to the possible extent. The individual processors
find it difficult to continue in this field due to low productivity
and quality problems.
The main objectives of the research are to find out how
the production is being managed in the seafood processing(freezing) 17industry
in Kerala and the reasons for low productivity and
poor quality of the products. The study includes a detailed
analysis of Location of the factories. Layout Purchase, production and storage patterns. Production planning and scheduling. Work Measurement of the processing of important products. Quality Control and Inspection. Management Information System
Description:
Department of Industrial fisheries, Cochin University of Science And Technology
Neelakandan Namboodiripad, K S; Dr.Kurup, P G(Cochin University of Science And Technology, March , 1984)
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Abstract:
The results of an investigation on the limits of the random errors contained in the basic data of Physical Oceanography and their propagation through the computational procedures are presented in this thesis. It also suggest a method which increases the reliability of the derived
results. The thesis is presented in eight chapters including the introductory chapter. Chapter 2 discusses the general theory of errors that are relevant in the context of the propagation of errors in Physical Oceanographic computations. The error components contained in the independent oceanographic variables namely, temperature, salinity and depth are deliniated and quantified in chapter 3. Chapter 4 discusses and derives the magnitude of errors in the computation of the
dependent oceanographic variables, density in situ, gt, specific volume and specific volume anomaly, due to the propagation of errors contained in the independent oceanographic variables. The errors propagated into the computed values of the derived quantities namely, dynamic
depth and relative currents, have been estimated and presented chapter 5. Chapter 6 reviews the existing methods for the identification of level of no motion and suggests a method for the identification of a reliable zero reference level. Chapter 7 discusses the available methods for the extension of the zero reference level into shallow regions of the oceans and suggests a new method which is more reliable. A procedure of graphical smoothening of dynamic topographies between the error limits to provide more reliable results is also suggested in this chapter. Chapter 8 deals with the computation of the geostrophic current from these smoothened values of
dynamic heights, with reference to the selected zero reference level. The summary and conclusion are also presented in this chapter.
Description:
School of marine sciences, Cochin University of Science And Technology
John Chellappan, N; Ramachandran, A(School of Industrial Fisheries, 2004)
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Abstract:
In this study the quality and process control factors during the production and storage of salted dried fish products. The study reveals that quantity of dry fish production in the state is decreasing and dry fish processing industry should be encouraged by central and state governments. The dry and wet salting may be carried out to a period of 4 to 8 hours respectively and time may depend on temperature, size, and concentration of medium. Demand is an unavoidable factor for sale of fish. The packed dry salted lots kept at room temperature are useful only for 20 days. The refrigerator- stored lots had more storage life and nutritional content are good up to 3 months. The cold storage stored dry salted lot had more storage life than the wet salted lot. The use of preservatives in salting is encouraged to reduce pH. The low temperature preservation maintains the nutritional value and quality for long period. It further encourages the labeling of nutritional value of dry fish as in tinned products.
Jayasankar, P; Dr.Alagarswami, K(Cochin University Of Science And Technology, June , 1989)
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Abstract:
From the point of view of rational exploitation and proper management
of the fishery resources as well as for the development of intensive aquaculture
of fishes through selective breeding, brood stock development, domestication
and genetic improvement, a sound knowledge of reproductive biology and
physiology of the candidate species is of great importance. In recent times, a
wealth of information on maturity, spawning habits, spawning periodicity, spawning
season, size at maturity and fecundity of commercially important fishes
has been generated.
Gametogenesis involves the transformation of Primordial germ cells in
the gonads into specialised cells or gametes, namely ova in the female and
sperms in male, through a series of complex morphological and cytological
events. The formation of male gamete is known as spermatogenesis. In the
female, the primary growth phase involving the formation of primary oocyte
from oogonia is known as oogenesis, which would be followed by the secondary
growth phase, in which considerable increase in the size of the oocyte occurs,
due mainly to accumulation of yolk. This process is known as vitellogenesis,
which would be followed by final maturation and ovulation of the ova.
In the present work, basic aspects of maturation and spawning, salient
features of gametogenesis and associated biochemical changes occurring during
these processes in an important cultivable fish, Sillago sihama belonging to
the family Sillaginidae have been investigated.
Description:
Department of Marine Sciences,Cochin University Of Science And Technology
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
Kuldeep, Lal Kumar; Dr.James, P S B R(Cochin University of Science And Technology, July , 1991)
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Abstract:
At present, there is paucity of information regarding the breeding
biology, especially from southeastern region, which differs in its climatic
features from northeastern coastal areas, where some attempts have been
made to study the biology of the fish, though not documented in detail
(Jhingran and Natarajan, I969; Patnaik and Jena, 1976; Kowtal, 1977; Roy
e_t _a_l_., I977). The present work, first to undertake detailed investigation
into reproductive aspects of the fish from India is not only confined to
biology, but extend to the study on histological as well as physiological
changes in the processes associated with natural reproductive cycle. The
main objective of the study is to develop a background for the standardisation
of subsequent artificial propagation techniques for the Sea Dass
The thesis is presented in three chapters. The first chapter; general introduction, surveys the literature pertaining to the status of research on Lates calcarifer with specific reference to reproduction and acquaculture. The second chapter entitled, materials and methods gives description regarding collection of specimens as well as samples in addition to the various analytical methodologies employed during the study.
Description:
School of marine sciences, Central institute of fisheries technology, Cochin University of Science And Technology
Sivachandrabose, K; Dr.Suseelan, C(Cochin University of Science and Technology, October 10, 1995)
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Abstract:
A study of the reproductive physiology of P. (P). semisulcatus wasundertaken as this information is an essential prerequisite for brood stock development for hatchery operations, and the results are embodied in this thesis. The thesis is presented in seven chapters. The protein, lipid and carbohydrate contents of ovary were estimated for the different vitellogenic phases. The protein, lipid, carbohydrate and cholesterol contents were estimated in testes and spermatophore.The thesis present the results of induced maturation experiments by eyestalk ablation, CNS extract injection and UV rays application on immature female prawns.
Murthy,P G K; Dr.Sharma,G S(Cochin University of Science and Technology, October , 1986)
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Abstract:
The thesis entitled Studies on Thermal Structure in the Seas Around India. An attempt is made in this study to document the observed variability of thermal structure, both on seasonal and short-term scales, in the eastern Arabian Sea and southwestern Bay of Bengal, from the spatial and time series data sets from a reasonably strong data base. The present study has certain limitations. The mean temperatures are based on an uneven distribution of data in space and time. Some of the areas, although having a ‘full annual coverage, do not have adequate data for some months. Some portions in the area under study are having data gaps. The consistency and the coherence in the internal wave characteristics could not be examined due to non-availability of adequate data sets. The influence of generating mechanisms; other than winds and tides on the observed internal wave fields could not be ascertained due to lack of data. However, a comprehensive and intensive data collection can overcome these limitations. The deployment of moored buoys with arrays of sensors at different depths at some important locations for about 5 to 10 years can provide intensive and extensive data sets. This strong data base can afford to address the short-term and seasonal variability of thermal field and understand in detail the individual and collective influences of various physical and dynamical mechanisms
responsible for such variability.
Lizen, Mathews; Dr.Chandramohanakumar, N(Department of Chemical Oceanography, School of Marine Sciences, 2000)
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Abstract:
In the present study the nutrient dynamics and fertility of Kuttanad waters is addressed. Kuttanad represent a wetland system with considerable agricultural activities. The hydrographical features of the Kuttanad waters are controlled by discharges from Manimala, Meenachil, Pamba, Achencoil and Muvattupuzha rivers and also by tidal intrusions of saline waters from Cochin backwaters during summers. The fertility of these water bodies were significantly high and supported good agricultural production. Kuttanad water forms the southern part of this aquatic systems and is considered as the most productive zones. As a part of the management scheme for a higher agricultural activity, the Thannermukkam bund was constructed to block and regulate the intrusion of saline water. The increased use of artificial fertilizers along with stagnant character of the water body in this area has resulted in sharp decline in the water quality, productivity and aquatic resources.