Assessment of Mercury Toxicity on Sensitivity and Behavioural response of 27-35 Freshwater Tropical Worm, Branchiura sowerbyi Beddard, 1892

By : Kishore Dhara , Nimai Chandra Saha , Asish Kumar Panigrahi , Arpan Kumar Mait

Page No: 27-35

Abstract
Though aquatic oligochaetes have often been used as indicator organisms to monitor aquatic pollution, however, the toxic impact of mercury on sensitivity and behavioural response of Branchiura sowerbyi remained uninvestigated. In lieu of this lacuna, the present study has been carried out. Significant mortality rate of B. sowerbyi at exposure times (24, 48, 72 and 96h) were recorded at 0.008, 0.040 and 0.060 mg/L of the toxicant (p<0.05). But the mortality rate of the worms showed significant variation (p<0.05) at all concentrations except 0.005 mg/L irrespective of exposure times. Pertaining to behavioural changes, clumping tendency was not altered significantly in the treated worms except at 0.06 and 0.08 mg/L of mercury at 48, 72 and 96h of exposure. The movement was gradually reduced at all the concentrations with the progress of time of exposure. Excess mucous secretion and reduced movement in the treated worms were observed at higher concentrations (0.04 to 0.06 mg/L) during 72 and 96h of exposure. At 0.08 mg/L, the worms showed excess mucus secretion at 48h and 72h of treatment but they lost their movement after 72h of exposure followed by faster decomposition and death.

Authors :
Kishore Dhara : Office of the Deputy Director of Fisheries, Gour Banga Zone, Govt. of West Bengal, Meen Bhawan, Mangalbari, Malda-732 142, West Bengal, India

Nimai Chandra Saha : Fisheries and Ecotoxicology ResearchLaboratory(Vice-Chancellor’s Research Group), Department of Zoology, University of Burdwan, Golapbagh, Burdwan-713 104, West Bengal, India.

Asish Kumar Panigrahi : Department of Zoology, University of Kalyani 741235, Nadia, West Bengal, India.

Arpan Kumar Mait : Department of Zoology, University of North Bengal, Raja Rammohanpur, District-Darjeeling, West Bengal-734013, India.
 

DOI: http://doi.org/10.32381/JAT.2019.34.1-2.3