| Abstract: | In this thesis a detailed sampling is conducted using grabs and dredges to access the qualitative and quantitative nature of the macrobenthos. A11 the animal contributing to the fauna are identified and their pattern of distribution and seasonal abundance are discussed. Affinity and diversity of polychaete fauna have also been studied. Importance of different benthic forms and their contribution to the standing crop are studied in detail. Trophic relationship between macrofauna and botton feeding commercially important fishes and prawns are also given attention. The physico-chemical aspects or the environment have been studied and their relation to the distribution and abundance of bottom fauna has been discussed. Environmental parameters such as temperature. salinity and dissolved oxygen. both in bottom and in the overlying waters. and rainfall were studied along with the benthos investigations. The physico-chemical nature of the sediments was also subjected to investigation. Influence of all those ecological parameters on the bottom fauna is discussed. A detailed quantitative faunal list of maorobenthio species and a brief systematic account of the polychaeta are also given. |
| Description: | School of marine sciences, Cochin University of Science And Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3342 |
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| Dyuthi-T1303.pdf | (6.767Mb) |
| Abstract: | In this present study macro benthos of minicoy island lakshadweep, an attempt has been made to study the distribution and community structure of benthos at different ecosystems. The main objectives of the study include the identification of benthic fauna, their distribution and composition, standing stock, qualitative and quantitative nature in relation to hydrography,seasons and sediment texture, community structure analysis and tropic relationships. This base line study at Minicoy,thus establishes that the benthos of sea grass and mangrove ecosystems(nursery grounds) determines the richness and diversity of demersal fish fauna at the nearby lagoon and reef areas to a great extent. Any serious stress on these ecosystems may lead to disappearance of certain fish species in the nearby future |
| URI: | http://dyuthi.cusat.ac.in/purl/972 |
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| Dyuthi-T0196.pdf | (5.208Mb) |
| Abstract: | This thesis Entitled macrobenthos of the continental margin (200-1000m) of south eastern arabian sea with special reference to polychaetes. The continental margins are geologically complex and hydrodynamically active regions of the ocean, where vital biogeochemical processes take place from a global perspective. The Eastern Arabian Sea is one of the most productive regions of the world, and as a result, vast amount of organic matter is supplied to the sub surface waters and sea bed of the Arabian Sea. In this study, data on faunal abundance, standing crop and faunal composition, together with sedimentary and environmental parameters were collected from three depths (200m, 500m & 1000m) in nine bathymetric transects along the South Eastern Arabian Sea (from Cape Comorin to Karwar) during three surveys. In the present study, five textural classes of sediments were identified from the SEAS margin, viz. sand, silty sand, sandy silt, clayey silt and admixture of sand, silt and clay. The composition of sand was higher in the southern region and decreased progressively towards the north. On the shelf edge and upper slope regions in the south (Cape to Kollam) in particular, sandy sediments dominated . |
| Description: | School of Marine Sciences, Department Marine biology,Microbiology and Biochemistry |
| URI: | http://dyuthi.cusat.ac.in/purl/3027 |
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| Dyuthi-T1002 | (8.117Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5275 |
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| Dyuthi T-2311.pdf | (11.41Mb) |
| Abstract: | The work was carried out with an objective to know the quantitative and qualitative nature of the macrobenthos in relation to the existing hydrographical parameters and sediment characteristics. With the above two cruises were conducted to collect materials. Representative samples were collected from each degree square of the western continental shelf. The study deals with the hydrographic parameters. The bottom water temperature, salinity and dissolved oxygen were measured. The findings showed variations according to depth and latitude. The study gives the details of sediment characteristics of the study area. 7 different types of substrata were noticed. It also explains the macro faunal composition and diversity, and the standing stock of macrobenthos. The wet-weight and numerical abundance of macrobenthic groups are included. The thesis discusses the relation between hydrography and macrobenthos, and sediment characteristics and macrobenthos, based on the results obtained by statistical analysis of the data. It also investigates the relation between macrobenthos and fishery. |
| URI: | http://dyuthi.cusat.ac.in/purl/84 |
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| Dyuthi-T0191.pdf | (14.19Mb) |
| 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 |
| URI: | http://dyuthi.cusat.ac.in/purl/4953 |
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| Dyuthi-T2029.pdf | (5.241Mb) |
| 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 |
| URI: | http://dyuthi.cusat.ac.in/purl/3004 |
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| Dyuthi-T0984.pdf | (4.664Mb) |
| Abstract: | Aquaculture is a form of agriculture that involves the propagation, cultivation and marketing of aquatic plants and animals in a controlled environment (Swann, 1992). After growing steadily, particularly in the last four decades, aquaculture is for the first time set to contribute half of the fish consumed by the human population worldwide. Given the projected population growth over the next two decades, it is estimated that at least an additional 40 million tonnes of aquatic food will be required by 2030 to maintain the current per capita consumption (FAO, 2006). Capture fisheries and aquaculture supplied the world with about 110 million tonnes of food fish in 2006. Of this total, aquaculture accounted for 47 percent (FAO, 2009). Globally, penaeid shrimp culture ranks sixth in terms of quantity and second in terms of value amongst all taxonomic groups of aquatic animals cultivated (FAO, 2006). In places where warm-water aquaculture was possible black tiger shrimp, Penaeus monodon became the preferred variety of shrimp cultivar owing to its fast growth, seed availability and importantly due to high prices it fetches (Pechmanee, 1997). World shrimp production is dominated by P.monodon, which accounted for more than 50 % of the production in 1999 (FAO, 2000). In the last few years the whiteleg shrimp, Litopenaeus vannamei, has replaced P.monodon in many countries. Indian shrimp culture is dominated by P.monodon with the East Coast accounting for 70% of the production (Hein, 2002). Intensive culture, apart from other problems, results in enhanced susceptibility of the cultured species to diseases (Jory, 1997), which in fact have become the biggest constraint in shrimp aquaculture (FAO, 2003). |
| Description: | National Centre for Aquatic Animal Health |
| URI: | http://dyuthi.cusat.ac.in/purl/3713 |
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| Dyuthi-T1670.pdf | (2.037Mb) |
| Abstract: | This thesis Entitled Marine actinomycetes as source of antimicrobial compounds and as probiotics and single cell protein for application in penaeid peawn culture systems. Ocean harbours more than 80% of all life on earth and remains our greatest untapped natural resource. The study revealed the potential of marine actinomycetes as a source of antimicrobial compounds. The selected streptomycetes were found to be capable of inhibiting most of the pathogenic vibrios, whichis a major problem both in hatcheries and grow out systems. The bioactive principle can be incorporated with commercial feeds and applied as medicated diet for the control of vibrios in culture systems.The hydrolytic potential inhibitory property against pathogens and non—pathogenicity to penaeid prawns make the selected Streptomycesspp.an effective probioic in aquaculture. Since there is considerably less inhibition to the natural in pond ecosystem the microbial diversityis being maintained and thereby the water quality. Actinomycetes was found to be a good source of single cell protein as an ingredient inaquaculture feed formulations. Large amount of mycelial waste (actinomycete biomassO is produced from antibiotic industries and this nutrient rich waste can be effectively used as a protein source in aquaculture feeds.This study reveals the importance of marine actinomycetes as a source of antimicrobial compounds and as a probiotic and single cell protein for aquaculture applications. |
| Description: | School of Marine Science, Division of marine biology, microbiology and biochemistry,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3043 |
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| Dyuthi-T1017.pdf | (3.657Mb) |
| Abstract: | The present study revealed the importance of marine actinomycetes as a potent source of bio active secondary metabolites. The selected isolates were capable of protecting Peaneus monodon against WSSV infection. They also proved to be inhibitory to vibrios and is a rich pool of hydrolytic enzymes. Their capacity to proliferate in saline environments and their property of non-pathogenicity to prawns makes them good candidates to be applied as probionts in penaeid shrimp aquaculture. They also enhanced the immune status of shrimps challenged with WSSV and act as a good source of antioxidants. Exploitation of the potential for the prophylactic and therapeutic measures in aquatic animal health management would be highly rewarding. This work is a preliminary study targeting marine actinomycetes as a source of antiviral compounds and as probionts in Penaeus monodon culture systems. More work is needed to understand the nature and mode of action of the bioactive compound, the various aspects of immune and antioxidant responses under challenge and when exposed to pro active treatments, and the dose and frequency of application of such compounds under rearing conditions. |
| Description: | Department of Marine Biology, Microbiology & Biochemistry,Cochin University of Science & Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2822 |
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| Dyuthi-T0842.pdf | (10.28Mb) |
| Description: | Department of Marine Biology,Microbiology and Biochemistry,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2789 |
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| Dyuthi-T0810.pdf | (9.286Mb) |
| Abstract: | Aquaculture has developed rapidly over the last three decades to become an important activity worldwide.The Food and Agricultural Organization (FAO) of the UN acknowledge that global fishery output must be increased by at least 50% to offset projected shortfalls in dietary protein by 2030.LAquaculture has developed rapidly over the last three decades and has become an importat industry as today’s demand for fish exceeds the natural supply.lmmunostimulants are chemical compounds that activate the immune system of animals and render them more resistant to infections by viruses, bacteria, fungi, and parasites. lmmunostimulants have been obtained from diverse natural sources where, microbial cell wall acts as the main source.The salient findings of the study are summariseSeven marine yeasts were screened for growth promoting and immunostimulant property in F. indicus. Candida sake S165 was found to be best in terms of its support for growth and protection against white spot virus infection.The study revealed that marine yeast Candida sake can be effectively used as potential source of immunostimulants for application in penaeid prawns culture systems. The study emphasise the fact that the dose and frequency of application of immunostimulants are to be standardised and validated before commercialisation to achieve optimum stimulation of the immune system and to avoid immune fatigue die to verdose.Marine yeast (whole cell) was found to support better immunostimulation compared to its cell wall component B-1,3-glucan. This study shows that administration of marine yeast (whole cell) or B-1,3-glucan as immunostimulants in aquaculture would definitely help in protection of the stock to a few more days even though total protection is not being imparted. This partial protection itself would be highly helpful to the farming industry so that they can get sufficient time to plan for a safe harvest and save the crop from cent percent mortality. |
| Description: | Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3110 |
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| Dyuthi-T1084.pdf | (6.001Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5333 |
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| Dyuthi T-2400.pdf | (8.371Mb) |
| Abstract: | As the title of the thesis indicates, a detailed analysis of microalgae, the major primary producers and the first link in aquatic food chains, was carried out during this study. Microalgae are either planktonic or benthic. The studies on these microscopic autotrophs are having an upsurge of interest recently due to their variations, adaptations, short generation time and various utilitarian aspects, including food, fodder and fuel. The surface water samples collected during the cruises (cruise nos. 189, 193, 195, 196, 203, 204, 205, 207 and 209) of Fisheries and Oceanographic Research Vessel (FORV) Sagar Sampada (Fig.2.2), conducted during the period from November 2000 to November 2002, are used as samples for microalgal estimation in the EEZ of India. The present research work includes the identification and distributional pattern of planktonic microalgae in the EEZ of India. The blooms encountered during the above mentioned cruises of FORV Sagar Sampada and the blooms of Kerala coast during the period from 2001-2005 are also studied |
| Description: | Department of Marine Biology, Microbiology and Biochemistry School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3259 |
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| Dyuthi-T1233.pdf | (7.433Mb) |
| Abstract: | the present study was undertaken with the following objectives: 1. Isolation and identification of yeasts from Arabian Sea and Bay of Bengal. 2. Molecular characterization of yeast isolates and phylogenetic analysis 3. Physiological and biochemical characterization of the isolates. 4. Proximate composition of yeast biomass and bioactive compounds. The Thesis is comprised of six chapters. A general introduction to the topic is given in Chapter1. Isolation and identification of marine yeasts are presented in Chapter 2. Chapter 3 deals with molecular identification and physiological characterization of Non- pigmented yeasts. Molecular identification and physiological characterization of pigmented yeast is presented in Chapter 4. Proximate composition of yeast biomass of various genera and their bioactive compounds are illustrated in Chapter 5. A summary of the results of the present study is given in Chapter 6. References and Appendices are followed |
| Description: | Department of Marine Biology, Microbiology and Biochemistry, School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3689 |
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| Dyuthi-T1655.pdf | (6.616Mb) |
| Abstract: | The study revealed the potential of marine yeasts as a source of single cell protein and immunostimulant for prawns. Prawns fed with the selected marine yeasts were showing more growth compared to the control feed and commercial feed. Yeasts being rich with proteins, vitamins and carbohydrates serve as a growth promoter for prawns as being evidenced in this study. The better performance of marine yeasts, D. hansenii S8 and S100 and C. tropicalis S186 compared to S. cerevisiae S36 as a feed supplement is worth investigating. Besides being a rich nutritional source, yeasts act as immunostimulants by virtue of its high carbohydrate (Beta, 1-3 glucan) and RNA content. Beta, 1-3 glucan, a cell wall component of yeasts /fungi is the most commonly used immunostimulant in aquaculture. The present study shows that even the whole cell yeast could serve as a good immunostimulant when supplied through diet. Extraction of Beta-1,3 glucan results in the removal of nutrients like proteins, vitamins etc. from the cell biomass.Utilization of the yeast biomass as such in the diet would help perform a dual role as nutritional component and immunostimulant for aquaculture applications. |
| Description: | Dept.of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2273 |
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| Dyuthi-T0580.pdf | (10.61Mb) |
| Abstract: | The present study provides an account of the occurrence and diversity of marine yeasts in the slope sediments of Arabian Sea and Bay of Bengal. It also gives a clear idea about the role of yeasts in the benthic realm of marine ecosystem. The lipolytic potential of the organisms indicate the presence of rich lipid moieties in the study area. The isolates, Candida sp. SD 302 and Pichia guilliermondii SD 337 were proved to have potential oil degrading property and can be employed as bioremediators of oil spill after further characterization. The black yeasts isolated during the study area were found to have high commercial value by virtue of the by-products obtained from them. The melanin and the melanin degrading enzyme extracted from these organisms are potential bioactive materials for application in cosmetology. |
| Description: | Department of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/xmlui/purl/1935 |
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| Dyuthi-T0427.pdf | (20.16Mb) |
| Abstract: | This thesis studied the impact of market orietnation on business performance, in the seafood industry, which is a unique situation wherein the firms were all 100% export oriented. The study was able to prove that in the context of the seafood indsutry, implementation of market orientation principles will lead to increase in business performance. The business performance variables were measured under two heads, namely economic performance and non-economic performance. Market orientation in Indian seafood firms was significantly and postiively related to both the performance measures. Under the non-economic performance, were the customer and employee consequences.Again market orientation was positively and significantly related to both the consequences.Thus, the implication arising from the study is this: market orientation in Indian seafood processing firms increases their business performance. The implementation of market orientation will help the seafood firms in gaining competitve advantages in exporting. This in turn will result in increased exports and the position of Indian seafood in the global market will be strengthened. It will thus become a leading player in the global fish trade. Next, the focus was on the effect of the antecedents on the market orientation of a firm. It was seen that several factors were antecedents to the adoption of market orientation principles. They include top management emphasis, conflict, centralization and reward system. It is noted that top management emphasis and support is vital to the market orientation programme. The top management needs to adopt market oriented behaviour and reinforce the need for being market oriented, for it to percolate down the line.Interdepartmental conflict is seen to affect market orientation positively. A large percent of the Indian seafood firms are traditionally family-owned companies, rather than professionally managed firms. This would result in promulgation of old ideas of management whereby, conflict was seen as a healthy exercise, which helped to build up each department's efficiency. But, this view in the long run proves to be detrimental to the firm's performance and must therefore be kept to a bare minimum, if any.Decentralisation of decision making facilitates the participation of the lower level employees and builds up their motivational levels and commitment to the firm. Thus employees are encouraged to make their own decisions, so that they can deal with customers faster and more efficiently. Reward systems help improve an employee's morale, provide encouragement and helps inculcate commitment and loyalty. It improves the employee's self worth and fulfills his need for achievement. A satisfied employee works better, produces more output and needs less supervision, and is happy, thereby reducing costs to the company for replacement and retraining, if the employee quits.Competitive intensity plays a moderating role on the market orientation business performance. Thus in times of greater competition, the relationship between market orientation and business performance grows stronger. Thus, this thesis was successful in investigating a positive relationship between business performance and market orientation. |
| Description: | School of Industrial Fisheries, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2886 |
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| Dyuthi-T0883.pdf | (6.490Mb) |
| Abstract: | In the equatorial oceans, the meridional currents are far less energetic than their zonal counterparts. The response of the Equatorial Indian Ocean to the seasonal reversals in the zonal wind field. is quite interesting and unique. A modest attempt, considering the shortcomings in the hydrographic data availability and distribution, is made to evaluate the variability in the zonal transport of mass. in_ both space and time. The peculiarities in its hydrological regime imposed upon by the seasonally varying winds is best appreciated when compared with the quasi permanent circulation characteristics of the Pacific and Atlanti'c.The major features of the tequatorial mass transport is outlined in the introductory chapter of this thesis for the Pacific and Atlantic Mass transport studies in the Indian Ocean, as can be seen from the earlier studies, gis“ the least known and understood, though could have captured the attention of both the experimentalist and the theoretician alike. owing to its complexity. Since in the Indian Ocean, the studies on the zonal mass transport are limited and are confined to the equator only, an attempt has been made to compute the mass transport extending from 5 N to 20 S. |
| Description: | Centre For Earth Science Studies,Cochin University Of Science And Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3571 |
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| Dyuthi-T1548.pdf | (6.305Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1228 |
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| Harish C M 1989.PDF | (336.6Kb) |
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