• Santanu Das

Lamellidens marginalis (Mollusca: Bivalvia: Eulamellibranchiata) is an important representative of filter feeding, bivalve mollusc which finds its habitat in the freshwater ecosystems of India. It feeds by filtering phytoplanktons, bacteria and other particulate organic matter suspended in the natural water body. Washing soda have been chemically identified as anhydrous sodium carbonate, is particularly used as a cleaning agent in India among the rural and urban populations, which frequently contaminates the freshwater lakes and ponds, the natural habitat of freshwater mussel Lamellidens marginalis. Hemocytes which circulates in the hemolymph of bivalves, act as blood cells and are functionally principal immunoeffector cells when comes in contact to various contaminants, xenobiotics or parasites. The various hemocytes of Lamellidens marginalis have been morphologically characterized and ascribed to be treated as a biomarker to ascertain the level of freshwater pollution by sublethal concentrations of washing soda, a natural contaminant of freshwater ecosystem. The diverse hemocyte subpopulations were morphologically characterized as blast-like cells, agranulocytes, granulocytes, hyalinocytes and asterocytes. A depression in the total hemocyte count (THC) and a gradual elevation in the percent of blast-like cells was observed under the long term exposure to experimental washing soda concentrations. Long term exposure to washing soda suppressed the relative densities of hyalinocytes, asterocytes, granulocytes and agranulocytes compared to the control animals.The present data indicates a shift in the immunological parameters of L. marginalis in washing soda contaminated freshwater ecosystems. The present study is aimed at estimating the degree of washing soda induced stress in L. marginalis and enumerating the hemocyte densities to establish it as a biomarker of aquatic pollution in several geographical regions of India. Long term exposure of hemocytes to experimental sublethal washing soda concentrations inflicted several morphological and nuclear damages like cell membrane disruption, hypervacuolation, membrane blebbing, micronucleation, binucleation, cytoplasmic smoothening. All these physical alterations in cellular morphology in its turn negatively affected phagocytic ability which is a clear manifestation of depressed cell mediated immune response of L. marginalis hemocytes.

Lamellidens marginalis, washing soda, biomarker, hemocytes, hemolymph, hypervacuolation, total count, differential count, micronucleation, binucleation

"Alteration of total count, hemocyte density and morphology of hemocytes of L. marginalis treated with washing soda", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 2, page no.579-589, February-2019, Available :http://www.jetir.org/papers/JETIR1902B85.pdf

"Alteration of total count, hemocyte density and morphology of hemocytes of L. marginalis treated with washing soda", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 2, page no. pp579-589, February-2019, Available at : http://www.jetir.org/papers/JETIR1902B85.pdf