Browsing by Author "Datta, Tanmay"
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Item Physico-chemical properties and ichthyofauna diversity in Karala River, A Tributary of Teesta River at Jalpaiguri District of West Bengal, India.(2011-07) Patra, Amal Kumar; Sengupta, Suman; Datta, TanmayThe present investigation was carried out on the Karalla River, a tributary of the river Teesta from February, 2009 to July, 2010 at three stations to study the seasonal change of physico-chemical factors and ichthyofaunal diversity. The constituents monitored included air and water temperature, turbidity, pH, total dissolved solid, total suspended solid, total solid, depth, conductivity, dissolved oxygen, biological oxygen demand, free carbon dioxide, chloride, salinity, total alkalinity, hardness, nitrate, phosphate and silicate. Through out the study period the water was hard and a significant variation of the rest parameters was observed. In respect of Ichthyofauna diversity, a total of fifty five species belonging to eight orders and twenty families were identified. Among the 55 species, thirty one species were found under the order Cypriniformes, ten species were found under the order Perciformes, seven species were found under the order Siluriformes, three species were found under the order Synbranchiformes and a single species was found under the order Osteoglossiformes, Anguilliformes, Beloniformes and Tetraodontiformes each. This observation indicates that Cypriniformes order is the most dominating of all other seven important orders. There are thirty three species which were common to all the three sampling stations and hence can be considered as migratory ichthyofauna. In this lotic system the diversity and distribution of fishes were uneven. The un-even distribution and diversity may be due to physico-chemical factors of water, substratum soil quality, and unscientific fish capture technology. The increase in species richness at down streams (SII and SIII) also may be due to the occurrence of submerged weeds.Item Zooplankton diversity and physico-chemical conditions of two wetlands of Jalpaiguri District, India.(2011-07) Datta, TanmayZooplankton diversity and physico-chemical parameters of two wetlands were studied to adjudge the health and potential threats of those wetlands. Zoolankton species diversity in both the wetlands was found to be quite high. Rotifer was the richest group having 48 species and Brachionus species (11) enjoy numerical superiority followed by Lecane (9). Only during premonsoon period rotifer and cladoceran diversity was significantly different in these two wetlands. Presence of higher number of copepods in all seasons signifies oligotrophic condition of these wetlands. Physico-chemical parameters indicate prevalence of good quality of water in both the wetlands but the wetland (Domohani Beel) having lesser zooplankton diversity experienced deterioration in water quality during premonsoon season. During premonsoon period Domohani wetland experienced intense ‘Boro’ cultivation having little water covered area with full of water hyacinth; and this poor condition reflects on its poor zooplankton diversity. Zooplankton diversity was significantly positively correlated with TSS, vegetative heterogeneity, and submerged macrophytes and negatively correlated with BOD and free CO2 of water. Loss of natural vegetation and eutrophic condition borne out of agricultural practices are thus hampering zooplankton life having an adverse effect on food chain.