Waterborne copper sulfate toxicity in Nile tilapia (Oreochromis niloticus) juveniles affect survival, growth, and physiology

ABSTRACT

This study aimed to evaluate the acute and long-term exposure to different cupric sulfate pentahydrate (CuSO₄.5H₂O) concentrations in Nile tilapia (Oreochromis niloticus). Experiment 1 evaluated the LC50-96 h of juveniles at 12 different CuSO₄.5H₂O concentrations (0.00, 0.2, 0.4, 0.8, 1.6, 3.2, 6.4, 12.8, 25.6, 51.2, 102.4, and 204.8 mg L^–1). In experiment 2, fish were exposed to four different sublethal cupric sulfate pentahydrate concentrations (0.0, 0.0069, 0.0696, and 0.6960 mg L^–1) with evaluations on days 20 and 40. In the first experiment, the LC50 and safe concentration for 96 h were, respectively, 6.96 and 0.6960 mg CuSO₄.5H₂O L⁻¹. In the second experiment, fish subjected to 0.6960 mg CuSO₄.5H₂O L^–1 decreased growth performance and survival, altered hematological parameters, and had hepatic vacuolation and liver necrosis. In conclusion, we have found that to control the excessive algae growth, fish could tolerate a concentration of up to 0.0696 mg CuSO₄.5H₂O L⁻¹ for 40 days.

KEYWORDS:

• Copper toxicity
• histological analysis
• liver necrosis
• Oreochromis niloticus
• safe concentration

Acknowledgments

The authors are grateful to CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil) for the research fellowships provided to C.E. Copatti (PQ 304329/2021-5), and CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil) - Finance Code 001 - for a research grant provided for R.T. Vasconcelos (process number 88882.431894/2019-01).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, upon reasonable request.

Additional information

Funding

This work was supported by CAPES (Coordination for the Improvement of Higher Education Personnel, Brazil) - Finance Code 001 - for a research grant provided by Ruth Tupiná Vasconcelos.