Chronic effects of copper and zinc on the fish, Etroplus suratensis (Bloch, 1790) by continuous flow through (CFT) bioassay

N D Don Xavier; S Bijoy Nandan; P R Jayachandran; P R Anu; A M Midhun; D Mohan

doi:10.1016/j.marenvres.2018.11.002

Chronic effects of copper and zinc on the fish, Etroplus suratensis (Bloch, 1790) by continuous flow through (CFT) bioassay

Mar Environ Res. 2019 Jan:143:141-157. doi: 10.1016/j.marenvres.2018.11.002. Epub 2018 Nov 13.

Authors

N D Don Xavier¹, S Bijoy Nandan², P R Jayachandran¹, P R Anu¹, A M Midhun¹, D Mohan³

Affiliations

¹ Department of Marine Biology, Microbiology and Biochemistry School of Marine Sciences, Cochin University of Science and Technology Fine Arts Avenue, Kochi, 682 016, Kerala, India.
² Department of Marine Biology, Microbiology and Biochemistry School of Marine Sciences, Cochin University of Science and Technology Fine Arts Avenue, Kochi, 682 016, Kerala, India. Electronic address: bijoynandan@yahoo.co.in.
³ Integrated Coastal and Marine Area Management-PD Government of India, Ministry of Earth Sciences, Chennai, 600 100, Tamil Nadu, India.

PMID: 30497666
DOI: 10.1016/j.marenvres.2018.11.002

Abstract

Copper (Cu) and zinc (Zn) play a vital role in the growth and development, however increased uptake causes deleterious effects in normal functioning of organisms. We have demonstrated in this contribution the tolerance limit of Cu and Zn on Etroplus suratensis (pearl spot) by Continuous Flow Through (CFT) bioassay and the biomarker responses. The accumulation for Cu, Zn and selected trace metals (Cr, Cd, Ni and Pb) from field conditions, as well Geo-accumulation index (I geo) and Contamination factor (C.F) suggested moderate to heavy pollution in the Cochin estuarine system. The 96 h LC₅₀ values for Cu was 1.74 ± 0.04 mg L^-1and that for Zn was 24.36 ± 0.58 mg L^-1 at 95% confidence interval. No observed effect concentration (NOEC) and low observed effect concentration (LOEC) for Cu and Zn were derived based on the survival rates. Chronic toxicity values for Cu and Zn were 0.23 mg L^-1 and 2.005 mg L^-1 respectively for 30 days period. The histological, biochemical, hematological and behavioral parameters showed significant variations at sublethal concentrations. Lamellar hyperplasia in gills, vacuolation combined with necrosis in liver, increased occurrence of melanomacrophage centres in spleen were noticed at chronic levels for both Cu and Zn. Tissue specific bioconcentration was observed for zinc and copper in gill and liver respectively, with least rate of bioconcentration observed in muscle tissues. Malaonate Dehydrogenase (MDH), Super oxide dismutase (SOD), Nonspecific esterase (EST) activity significantly varied compared to control at NOEC and LOEC values in both the metals. The hematological and genotoxic alterations as decrease in erythrocyte count, lymphocytes, hemoglobin concentration and hematocrit percentage were significantly reduced (p < 0.05) and increased thrombocytes and neutrophils, increased frequency of micronuclei, lobed, blebbed and notched nuclei and binucleate cells were characteristic for the metals at the sublethal concentrations. The frequency of behavioral changes remained significantly higher at chronic level than the control group. Thus such CFT based studies are important for precisely mapping the toxicity changes in organisms and also to develop suitable water quality guidelines.

Keywords: Biomarker changes; Continuous flow through (CFT); Copper; Etroplus suratensis; Zinc.

MeSH terms

Animals
Biological Assay
Cichlids / metabolism*
Copper / metabolism
Copper / toxicity*
Environmental Biomarkers
Environmental Monitoring
Gills / drug effects
Liver / drug effects
Metals, Heavy / analysis
Metals, Heavy / toxicity
Muscles / drug effects
Trace Elements
Water Pollutants, Chemical / toxicity
Zinc / metabolism
Zinc / toxicity*

Substances

Environmental Biomarkers
Metals, Heavy
Trace Elements
Water Pollutants, Chemical
Copper
Zinc