Evaluation of Freshwater Toxicity with Hydra as a Test Animal
Suprakash Kar* and A. K. Aditya1
*Sainthia High School, P.O. -Sainthtia, Dist.-Birbhum,
West Bengal, Pin-731234, India
1Department of Zoology (DSA-UGC, Visva-Bharati, Santiniketan, India
ABSTRACT
The emphasis in assessing pollution in freshwater ecosystem has been demonstrated with hydra, a freshwater solitary polyp of Cnidaria. It yields a unique plasticity in auto-regenerating, cell replacement, and cell renewal system. Heavy metal Cadmium is an extremely potential toxic element for living and even a very minute dose (0.5 ppm) of Cadmium-chloride can initiate noticeable damage to the body organization of hydra within a short time. Two methods have been employed in measuring the toxicity of hydra. One is the determination of median lethal concentration (LC50) of Cadmium-chloride by Probit Analysis method, while the second one involves the progressive changes in morphological structures through scoring procedures. The second method is more accurate in determining the lethal toxicity. Rural people may use this method for detection in toxicity hazards in freshwater more easily and precisely without having any statistical knowledge.
INTRODUCTION
Water is an essential natural resource required for all life activities and ecological functions. It is used by man for irrigation, navigation, industries, electricity generation, and a variety of domestic and commercial purposes. But water quality is continuously degraded by the activities of modern civilization mainly through industrial effluents and agriculture pesticides The regular entry of pesticidial and industrial pollutants into the natural resources eventually causes physical, chemical, and biological deterioration of the water when its natural purifying capacity is exceeded.
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