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

ABSTRACTCurrent 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. tubifexSublethal cadmium exposure can impact the physiological functioning of annelids in the wild.KEYWORDS: Cadmiumacute toxicityTubifex tubifex; heavy metaloxidative stress AcknowledgmentsWe are thankful to the Department of Zoology, The University of Burdwan for providing the laboratory facilities.Disclosure statementNo potential conflict of interest was reported by the author(s).Data availabilityThe datasets generated during and/or analysed during the current study are available from the corresponding author upon reasonable request.Additional informationNotes on contributorsNeha MajumdarNeha Majumdar is currently working as a Research Scholar in the Post Graduate Department of Conservation Biology, Durgapur Government College, Paschim Bardhaman, West Bengal, India. She is working in the field of ecotoxicology and fishery sciences. Her area includes assessing the role of heavy metals and their effects on aquatic organisms, measuring the stress enzymes.Nimai Chandra SahaProf. Nimai Chandra Saha is currently working as Professor in Zoology, Bidhannagar College, Kolkata, West Bengal. Prof. Saha is the former Vice Chancellor, The University of Burdwan (2016-2023). He has a long and vast experience in academia and administration. At present he has published 200 papers, review articles in various national and international repute journals. 12 scholars were already awarded Ph.D. under his supervision while 6 Ph.D. scholars are currently working under his guidance. Already 8 scholars were received Post Docs from him. Prof. Saha has spent 38 years in research on Ecology and Environmental Sciences, Aquatic Toxicology, Fisheries Sciences and 33 years in teaching. He has chaired as principal in several Government and Government Aided Colleges across the West Bengal under West Bengal Senior Education Service.Priyajit BanerjeePriyajit Banerjee is a DST-SERB National Postdoctoral Fellow (NPDF) at the Ecotoxicology Research Laboratory, Department of Zoology at the University of Burdwan. His scientific focus rests on elucidating the molecular mechanisms involved in the toxicity of eco-toxicants. He is also working to reveal the mechanism of infection to fish pathogenic fungus.Tapajit BhattacharyaTapajit Bhattacharya is a conservation biologist and wildlife enthusiast deeply interested in terrestrial and aquatic ecology, especially in the Himalaya and other mountain ecosystems. He is also interested in landscape ecology, remote sensing, and analytical frameworks. An expert on Himalayan mammals and birds, he is currently posted in the Postgraduate Department of Conservation Biology at Durgapur Government College as an assistant professor under the West Bengal Education Service and involved in research activities on aquatic and terrestrial fauna of West Bengal.Shubhajit SahaDr. Shubhajit Saha is currently working as Assistant Professor, Department of Zoology, The University of Burdwan, India. Dr Saha has eleven years of research and five years of teaching experience. He has published 58 research and review articles in reputed journals. Dr Saha has already attended and presented papers in various national and international conferences. He is working in fishery science, aquatic toxicology, wetland hydrobiology, plankton and ichthyofaunal diversity, histopathological alterations and microplastics pollution. He is a life member of the Electron Microscopic Society of India, Indian Science Congress Association and Indian Ecological Society, Ludhiana, Punjab, India. Dr. Saha is the Principal Investigator (PI) of a SERB-SRG project.