Hydrobiological parameters, population density and distribution pattern in the gastropod Nerita (dostia) crepidularia Lamarck, 1822, from mangroves of Vellar estuary, Southeast India

In the present study, the seasonal variation in physic-chemical parameters, population density and distribution pattern of Nerita crepidularia in the mangroves of Vellar estuary, Tamil Nadu was studied for a period of one year (January to December). The physico-chemical parameters such as temperature (atmospheric and water), pH, salinity, dissolved oxygen and rainfall were estimated. The atmospheric and water temperature ranged from 24 to 38 and 22 to 36°C, respectively. The pH ranged between 6.7 and 7

EFFECT OF DYE INDUSTRY EFFLUENT ON GROWTH AND BOCHEMICAL CHANGES OF COMMON CARP CYPRINUS CARPIO VAR. COMMUNIS

The present study deals with the effect of dye industry effluent on growth and biochemical changes of common carp Cyprinus carpio var. communis grown for a period of 40 days. The dye industry effluent was collected from Chinnalapati, Dindi gul, Tamil Nadu, India. Physico-chemical characteristics of dye industry effluent such as colour, pH, electrical conductivity, total Solids, total dissolved solids, total suspended solids, total hardness, alkalinity, Sodium, potassium, calcium, chloride, dissolved oxygen, dissolved carbon dioxide, BOD and COD were estimated. For the present study common carp C. carpio (1.24 + 0.2 g) was collected from Pandian Fish Farm, Dindigul. Tamil Nadu, India. Trainee feed and experimental feed were prepared based on the protein content. Different concentrations of dye industry effluent on the survival of the carp shows that the LCso at 96 hr exposure was found as 63%. Different sub-lethal concentrations of dye industry effluent such as 5, 10, 15 and 20% were utilized for growth studies. Feed consumption was higher in control and lower in Ex. IV containing 20% of dye industry effluent. Feed conversion efficiency, feed conversion ratio, growth, percentage growth, relative growth rate, assimilation, gross and net growth efficiency were lower in Ex. V. Metabolism was higher in Ex. IV containing 20% dye industry effluent. Protein, carbohydrate and lipid content in the muscle of C. carpio was decreased when the concentration of effluent increased. From the results it is inferred that the feed utilization parameters of Common carp was decreased with increasing concentration of dye industry effluent

Development of Fuzzy Logic-Based Speed Control of Novel Multilevel Inverter-Fed Induction Motor Drive

This paper presents the transformer-based multilevel inverter-fed induction motor drive. The development of new technology of power electronic switches and control techniques for inverter-based speed control of induction motor has led to the usage of induction motor in industrial and domestic applications. In this work, the stator winding of induction motor is fed through proposed five-level transformer-based symmetrical inverter, which consists of unidirectional and bidirectional switches, mid-point transformer and capacitors as voltage divider network to produce multilevel output voltage at the load side. The speed of the induction motor is varied by changing supply voltage of an induction motor by adjusting width of the pulse width-modulated signal. A speed controller has been implemented through fuzzy logic controller for performing closed loop operation of single phase induction motor drive. The ability of fuzzy-based speed controller can reduce the undesirable sustained oscillations in speed of induction motor drive and also provide better machine performance than conventional linear controller. The proposed controller performance of multilevel inverter-fed induction motor drive system is validated through MATLAB simulink environment

A checklist of malacofauna of the Vellar Estuarine Mangroves, India

A survey conducted to know the diversity of malacofauna in Vellar estuarine mangroves (southeast coast of India). In this study, 13 species of molluscs (10 species of gastropods - Melampus ceylonicus, Cerithidea cingulata, Cassidula nucleus, Pythia plicata, Neritina (Dostia) violacea, Littorina scabra, Littorina melanostoma, Ellobium aurisjudae, C. obtusa T. telescopium and Assiminea nitida and 3 species of bivalves - Perna viridis, Crassostrea madrasensis and Modiolus metcalfei were recorded. M. pulchella, C. obtusa, L. scabra and N. violacea were found arboreal. T. telescopium, C. cingulata and E. aurisjudae were found crawling on the intertidal mud

Gastropod shells used as a Biomonitor

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Some valuable fatty acids exposed from wedge clam, Donax cuneatus (Linnaeus)

The fatty acid compositon of the wedge clam Donax cuneatus collected from the sandy beach of Cuddalore (Southeast coast of India) was determined. In the analysis, the fatty acid profile by gas chromatography revealed the presence of higher amount of saturated fatty acids (35.28%) than mono (12.71%) and polyunsaturated (11.72%) fatty acids. Among the saturated fatty acids, the stearic acid contributed the maximum amount of 15.68 %. Whereas the monounsaturated fatty acids (MUFA) were accounted for 26.57 % with mostly 16:1 7c (12.71%), fatty acid. Among the PUFA 20:4 6c (6.75%) and 18:2 6c (2.41 %) acid contents were high. Omega – 6 fatty acids accounted for 10.74 % of total PUFA and omega – 3 fatty acids were accounted for 0.48 %. Thus the present study enlightens the possible role of this clam in the field of human nutrition