Acute and sub-acute toxic effects of cadmium to freshwater tropical oligochaete Tubifex tubifex with special reference to oxidative stress and behavioural biomarkers

Abstract

ABSTRACT Current environmental issues include heavy metal contamination. Cadmium pollution in aquatic environments harms aquatic creatures and can pass to people through food chains. Cadmium poisoning damages bones, kidneys and causes cancer. Tubifex tubifex is a well-known water pollution indicator because of its good adaptation power in environmental pollution. Tubifex sp. is chosen as the test animal in this study since it is an indicator species and also a model non-target organism in ecotoxicology. The aim of this present work is to assess the toxicity of cadmium nitrate on Tubifex tubifex as a biomarker. Acute toxicity of cadmium nitrate was analysed by measuring the 96 h LC50 value. Physical observations revealed that cadmium induced autotomy of the caudal region of the worm and induced more mucus secretion. Behavioural alterations like changes in mucous secretion, clumping tendency and wrinkling effect were observed in cadmium-treated worms. Antioxidant enzymes level (MDA, CAT and SOD) increased significantly on cadmium nitrate exposure. In general, biomarker data show that cadmium exposure has stress-related consequences at the biochemical and physiological levels, reducing the overall health and survival of such animals. Highlights The toxicity of the heavy metal cadmium in acute and sub-acute levels was investigated in Tubifex tubifex. The goal of this study was to look at the effects of cadmium on oxidative stress and behavioural biomarkers in T. tubifex Sublethal cadmium exposure can impact the physiological functioning of annelids in the wild.