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S. K. Sasmal ¹, A. Choudhury ¹, G. Dash ²

Affiliations
1 S. D. Marine Biological Research Institute, Bamankhali, Sagar Island, 24-Pgs (S), West Bengal, IN
2 Department of Pathology and Microbilogy, West Bengal University of Animal and Fishery Sciences, Chakgaria, Kolkata-700094, West Bengal, IN

Abstract

Investigation on some limnological factors like salinity and pH as well as species diversity of ichthyoplankton at three different sampling stations, viz., Light house (Station-1), Kachuberia (Station-2) and Haldia (Station-3) in the Hooghly estuarine complex of West Bengal was carried out. Samples of ichthyoplankton and water were collected every month during 2008. Station-1 recorded higher values of salinity, pH and species diversity compared to those of Station-2 and Station-3. The salinity and pH played an important role for survival of ichthyoplankton in the estuarine environment. Species diversity of ichthyoplankton also varied among the sampling stations. In all the stations maximum number of ichthyoplankton was available during pre-monsson (March to June) and minimum during monsoon (July to October). The species diversity gradually declined from the mouth towards the upper stretches of the estuary with the decrease in the salinity and pH of water.

Keywords

Estuary, Salinity, pH, Ichthyoplankton, Diversity.

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G. Dash ¹, S. K. Parida ¹, S. K. Sasmal ², S. N. Sahoo ¹

Affiliations
1 Parasitology Laboratory, Department of Fishery Pathology and Microbiology, West Bengal University of Animal and Fishery Sciences, Kolkata-700 094, West Bengal, IN
2 S.D. Marine Biological Research Institute, Bamankhali, Sagar Island, Sundarbans, 24-Pgs.(S), West Bengal, IN

Abstract

Hydrological parameters like dissolve oxygen, pH, turbidity, temperature, alkalinity, free carbon dioxide and salinity which have their direct influence upon the fish health with reference to the occurrence of argulosis in Indian major carps were studied in low saline bheries of West Bengal from March, 2006 to February, 2007. The high organic load which caused the over production of plankton leading to depletion of dissolve oxygen, increasing carbon dioxide to lethal level, high rate of ammonification leading to low alkalinity and fluctuation in temperature aggravates the occurrence of parasitic infection. Most of the parameters were found to be significant at 5% level and few were significant at 1% level. It was found that the above variables had definite impact individually or in combination on the prevalences of argulosis. Out of all the water parameters, temperature, alkalinity, dissolve oxygen and salinity were found to be the deciding factors for incidence of argulosis in low saline bheries of different locations of West Bengal. The prevalence of Argulus was less in October-November and it became epidemic in February-March and gradually declined in April.

Keywords

Argulosis, Indian Major Carps, Water Quality, Low Saline Bheries.

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S. K. Sasmal ¹, A. Choudhury ¹, G. Dash ²

Affiliations
1 S. D. Marine Biological Research Institute, Bamankhali, Sagar Island, 24 Parganas (S), West Bengal, IN
2 Department of Fishery Pathology and Microbilogy, West Bengal University of Animal and Fishery Sciences, Chakgaria, Kolkata-700094, West Bengal, IN

Abstract

The fish juveniles surveys were conducted in Hooghly estuary near Sagar Island in Indian Sundarban in 2008 to study their composition, diversity, distribution and seasonal occurrence. A total of 65 species belonging to 27 genera under 20 families were identified from two stations of Hooghly estuary at Sagar Island, viz., Baguakhali and Chemaguri. Of the 20 families, Engraulidae represented highest diversity of 12 species, followed by Mugilidae (8 species), Chipeidae (7 species) and Gobiidae (6 species). The diversity of species was minimum during post-monsoon and maximum in pre-monsoon periods. The most doninant families were Engraulidae, Mugilidae, Culpeidae, Gobidae and Cynoglossidae. The composition and diversity fish juveniles in the Baguakhali was higher than that of Chemaguri in all seasons.

Keywords

Fish Juveniles, Composition, Distribution, Hooghly Estuary, Sundarbans.

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