Glycogen degrading enzymes and their regulation in benthic animals and estuarine fish

Alpha glucan phosphorylase plays a very significant role in glycolysis. The inhibition and activation of this enzyme have significant effect on the rate of glycolysis. The rate of glycolysis is also determined by the interconversion between the active 3 and inactive Q forms of phosphorylase by two specific enzymes called phosphorylase phosphatase and phosphorylase kinase. The allosteric properties and interconversion mechanism reported for well—studied animal muscle phosphorylases do not fall under a general pattern. Studies using purified phosphorylase from marine sources are scanty. Detailed studies using specialised tissues from more marine animals are necessary to find the factors that control the properties and activities of the enzyme. This thesis is an attempt in this direction. The thesis deals with a detailed study of the control of the phosphorylase by both allosterism and interconversion between the g and b forms from four different aquatic animals of different habitat. Phosphorylase frm the four different animal muscles were purified either partially or completely and the kinetic and control properties were studied.

Impact Assessment Of Biocides On Microalgae - A Study In Vitro

The present study was undertaken to make a detailed investigation for_ the assessment of specific impact of commonly used biocides at the lower trophic level of food chain i.e., microalgae by using batch culture techniques in the laboratory. Microalgal representatives from three habitats i.e., fresh water, estuarine and marine were investigated. The different biocides selected are of common use in the agricultural practices. Because of the importance of microalgae as live feed for larval and postlarval stages of different aquatic organisms, the fluctuations in algal populations as a result of biocide treatment will surely affect the food chain. These studies are also of significance in setting the criteria and standards for water quality management by suggesting threshold values of different biocides tested, beyond which they affect the ecosystem adversely. The thesis has been divided into six chapters

Dynamics Of Pesticides In The Backwaters Of Kuttanad

The tremendous growth in industrial production and the consequent improving in the standards of living have provoked worldwide discussion on environmental quality. The question of abusive use of pesticides for crop protection and vector control programmes is only one aspect of this entire complex. Inspite of this, tendentious publications such as Rachel Carson’s Silent spring have brought crop protection into the foreground of environmental discussions. The persistence and high stability of organochlorine pesticides are regarded as problematic and the accumulation of pesticides residues and its metabolites in the different compartments of the environment is one of the major concerns. Because of their persistence in the aquatic environment and biomagnifications in food chain, the continuous use of pesticides will have wider implications not only in aquatic environmental quality but also on human health. The residual levels of these persistent chemicals exceed their permissible limits, and get partitioned among the constituent phases of the aquatic systems. Crop protection is only part of the agricultural economy and in agriculture itself has led to the most fundamental changes in the human environment. So, in all areas of life one must weigh the desired advantages against possible disadvantages. The proposed thesis is based on the investigations on the distributions of organochlorine and organophosphorus pesticides in the waters and sediments of Kuttanad backwaters. Kuttanad, a unique agricultural area, which forms the southern part of the Vembanad lake, is a deltaic formation of four river systems entering the southern part of the Cochin estuary. No systematic study has ever been done to assess the ecotoxicological impact of these diverse chemicals and their metabolites in Kuttanad area. So, a detailed systematic and rigorous investigation on the distributions of these persistent chemicals is carried out. The thesis is divided into 7 Chapters

‘Systematics and pathogenicity of Vibrionaceae associated T ¢ S with the larvae of M. rosenbergii in hatchery

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.

Integrated Coastal Water Quality Assessment Of Andrott Island, Lakshadweep

Assessment water’ quality nowa-days in global scenario implies the need for a reference point against which monitoring can be measured and weighed. Aquatic ecosystenis as part of the natural environment are balanced both witliin tlicinselves and with other environmental compartments and this equilibrium is subject to natural variations and evolutions as well as variations caused by human intervention. The present assessnient is to identify. and possibly quantify, anthropogenic influences over time against a “natural baseline situation. Water pollution problems have only recently been taken seriously in retrospect. Once damage occurred, it becomes immeasurable, and control action cannot be initiated

Ecotoxic Metal Records and its Degree of Geochemical Symphony in the Niche of Cochin Estuarine System- A Theraptic Perspective

The heavy metal contamination in the environment may lead to circumstances like bioaccumulation and inturn biomagnification. Hence cheaper and effective technologies are needed to protect the precious natural resources and biological lives. A suitable technique is the one which meets the technical and environmental criteria for dealing with a particular remediation problem and should be site-specific due to spatial and climatic variations and it may not economically feasible everywhere. The search for newer technologies for the environmental therapy, involving the removal of toxic metals from wastewaters has directed attention to adsorption, based on metal binding capacities of various adsorbent materials. Therefore, the present study aim to identify and evaluate the most current mathematical formulations describing sorption processes. Although vast amount of research has been carried out in the area of metal removal by adsorption process using activated carbon few specific research data are available in different scientific institutions. The present work highlights the seasonal and spatial variations in the distribution of some selected heavy metals among various geochemical phases of Cochin Estuarine system and also looked into an environmental theraptic/remedial approach by adsorption technique using activated charcoal and chitosan, to reduce and thereby controlling metallic pollution. The thesis has been addressed in seven chapters with further subdivisions. The first chapter is introductory, stating the necessity of reducing or preventing water pollution due to the hazardous impact on environment and health of living organisms and drawing it from a careful review of literature relevant to the present study. It provides a constricted description about the study area, geology, and general hydrology and also bears the major objectives and scope of the present study.

Studies On Some Aspects Of Phytoplankton

The present study is concentrated on a composite group of algae of phy— toplankton. The algae in the aquatic environment are the most important of all ch1orophy1l- bearing life on earth on which considerable attention is being given on account of their supreme status in the aquatic food chain. Though the higher plants serve as the major primary producers in the terrestrial biocycle, the primary producers in the aquatic ecosystem especially in the marine environment-" assume unparalleled significance ‘because of their c'ontribution.to the high magnitude of production generating the fishery resources

Studies on The Ecology And Production of Algae in Prawn Culture Systems

Existing method of culture were largely based on empirical knowledge. Lacking a scientific basis as such methods did, they were often wasteful and suffered severe limitation. Modern methods of fish and prawn culture based on scientific research, have revolutioned the industry in recent years and not only extended its scope to cover the whole country but led to increased fish and prawn production. An understanding of the biological capability of the water in the perennial and seasonal culture ponds, and the nature and extent of the influence of the abiotic factors on the production of organisms in the primary level of food chain would contribute to effectively implement management measures in the stocking strategies and in the evaluation of economics of production of prawns. It is against this background that the present topic of investigation "Studies on the ecology and production of algae in prawn culture systems” was selected.

Studies on the effects of selected trace metals on Matapenaeus Dobsoni (MIERS)

This thesis is an attempt by the author to assess the suitability of Metapenaeus dobsoni (Miers), an economically important crustacean species as a sentinel organism of trace metal pollution. The results of detailed investigations on seasonal variation, bioassay, accumulation and depuration of three metals viz., mercury, copper and zinc are presented and discussed. The importance of trace metals in the aquatic environment and their present status in the study area - Cochin backwaters, the significance of crustacean fisheries, the species M. dobsoni and the objectives of the present studies are described in Chapter 1. The methodology adopted during the investigation is given in Chapter 2. Chapter 3 delineates the seasonal variation of Hg, Cu and Zn in the edible and non-edible parts of M. dobsoni collected from Cochin backwaters for a period of one year (June 1984-May 1985). The results of bioassay experiments are given in Chapter 4. Kinetics of accumulation ,retention and depuration of trace metals, their biological half-life, the influence of size group and environmental factors are given in Chapter 5. The effect of these metals on the physiological response of M. dobsoni viz. oxygen consumption is included in Chapter 6. A summary and list of references are also appended.

Biochemical and molecular studies of cadmium resistance and metal biosorption in bacterial species isolated from cochin environment

Cochin, commercial capital of Kerala, located on the west-coast of South India has a large number of chemical and sea food industries. Earlier studies in the past indicated that these industries contribute to heavy metal pollution, particularly mercury, copper, and cadmium, in Cochin backwater. Hence, in the present study, it was desired to isolate cadmium resistant bacteria from effluent discharged by chemical industry with a view to develop an ideal bioremediation process for safe discharge of industrial effluent in to the nearby aquatic environment. Effluent from three industries, located in the industrial belt of Cochin, were collected from the discharge point and cadmium resistant bacteria were screened using standard microbiological techniques

“Stress Responses of Stinging Catfish Heteropneustes fassilis (Bloch) to Organophosphorus Insecticide Monocrotophos”

Poisoning by pesticides from agricultural fields is a serious water pollution problem and its environmental long-term effect may result in the incidence of poisoning of fish and other aquatic life forms (jyothi and Narayan, 1999). Fishes like Heteropneustesfbssilis and C/arius batrac/nus are especially prone to serious pesticide pollution as their habitat is mostly the agriculture area. Though only few studies are conducted in this area, it can be assessed from the local information that, population of such fish is on the verge of vulnerability due to extensive use of pesticides. The knowledge of sublethal effects of xenobiotic compounds on hematological parameters, enzyme activities and metabolite concentrations is very important to delineate the fish health status and provide a future understanding of ecological impacts. These pesticides act by causing inhibition of cholinesterase enzymes (ChE) by formation of enzyme inhibitor complex (O'Brien, 1976) and damaging the nervous system. These effects may result in metabolic disorders. Associated to cholinesterase activities, a study of other enzymes such as phosphatases and aminotransferases close to intermediary metabolite determination provides a wider view of metabolism. Interest in toxicological aspects has grown in recent years and research is now increasingly focused on mechanistic aspects of oxidative damage and cellular responses in biological system. The term ‘biomarker’ is generally used in a broad sense to include almost any measurement reflecting an interaction between a biological system and a potential hazard, which may be chemical, physical or biological (WHO, 1993). As biomarker stands for immediate responses, they are used as early warning signals of biological effects caused by environmental pollutants. The present work attempts to assess the toxicity of organophosphorus insecticide monocrotophos on the experimental organism selected for this study namely stinging catfish (Heteropneustesfossi/is) (Bloch), and to probe into the stress responses of the organism

Haematological and Toxicological studies on brackish water fish Etroplus maculatus (Bloch)”

Fishes are one of the most important members of the aquatic food chain, and through them some toxicants may reach human beings as well. The selection of organisms for toxicity test is mainly based on certain criteria like its ecological status, position within the food chain, suitability for laboratory studies, genetically stable, uniform populations and adequate background data on the organism (Buikema et al., 1982). The species selected for the present study Etroplus maculatus satisfy most of the above protocols. Rechten (1980) opined it as a laboratory favorite of fish researchers. However, there are difficulties in the rise of fishes for pollution assessment impact. Most important of these is our limited understanding of the mechanism of toxicity. The interpretation of the significance or specificity of a measured biological response could there for become difficult. Not withstanding these limitations, attempts have been made to the normal haematology and to analyze the impact of heavy metal at realistic levels to the experimental media, on the haematology, and enzymatic activity and histology of Etroplus maculatus

Vibrio harveyi phages: Isolation, characterization and evaluation of their potential as phage therapeutics on Vibrio harveyi in shrimp hatcheries

Aquaculture is a global industry providing food and employment thereby contributing to the economy. For the sustenance of aquaculture, disease management is a major requirement. Among the bacterial pathogens Vibrio harveyi remains to be the major one especially in shrimp culture systems. Rapid and mass mortality of shrimp larvae due to Vibrio harveyi infection is well known, and the pathogen causes serious economic losses in grow out systems as well. It suggests that a well defined management strategy has to be built up to protect the crop from Vibrio harveyi infection in aquaculture systems. Antibiotics have been the choice for quite some times which led to residues in meat and development of multidrug resistant bacteria which invited ban on their application. In this context several alternate options have been thought off such as probiotics, immunostimulants and vaccines. Phage therapy is yet another option. Phages being natural parasites of bacteria and are abundant in aquatic environments their application to control bacterial pathogens in aquaculture has commendable potential in lieu of antibiotics. For that matter the therapeutic effect of phages has been proven in several antibiotic resistant pathogens inclusive of Vibrio harveyi.

Molecular Approaches For Characterization And Determination Of Pathogenicity Of Vibrios With Special Reference To Vibrio Harveyi From Penaeus Monodon Larval Production Systems

The present study focuses on vibrios especially Vibrio harveyi isolated from shrimp (P. monodon) larval production systems from both east and west coasts during times of mortality. A comprehensive approach has been made to work out their systematics through numerical taxonomy and group them based on RAPD profiling and to segregate the virulent from non- virulent isolates based on the presence of virulent genes as well as their phenotypic expression. The information gathered has helped to develop a simple scheme of identification based on phenotypic characters and segregate the virulent from non virulent strains of V. harveyi.

A marine actinomycete nocardiopsis mccb 110 as source of novel drugs to manage vibriosis

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).