Change of osmoregulatory and hematological parameters in tilapia (Oreochromis niloticus) after exposure to sublethal mercury concentrations
|Author(s)||Handayani Kiki Syaputri1, Soegianto Agoes1, Lignot Jehan-Hervé2|
|Affiliation(s)||1 : Department of Biology, Faculty of Science and Technology, Universitas Airlangga, Kampus C, Jl Mulyorejo, Mulyorejo, 60115, Surabaya, Indonesia
2 : UMR MARBEC (University of Montpellier, CNRS, IFREMER, IRD), Place Eugène Bataillon, 34095, Montpellier, France
|Source||Emerging Contaminants (24056650) (Elsevier BV), 2020 , Vol. 6 , P. 337-344|
|Keyword(s)||Mercury, Tilapia, Osmoregulation, Serum ions, Blood, Aquatic toxicology|
The effects of Hg exposure on blood parameters and gill physiology of tilapia (Oreochromis niloticus) were analyzed. Fish maintained in freshwater were exposed for 7 days (d) to sublethal mercury concentrations (0.1 and 1 mg/L). Blood serum osmolality (SO), sodium (Na+), potassium (K+) and chloride (Cl−) ionic concentrations, and hematological parameters were assessed after 1 up to 7 d of exposure. Serum osmolality and ionic concentrations of exposed fish appeared differently affected throughout the experimental period compared to the controls. Osmolality was reduced at the 2 tested concentrations but Na+ and Cl− contents were only altered at 1 mg/L of Hg after 1 d of exposure and values rapidly returned to the control values thereafter. K+ content was also modified and significantly increased at both concentrations after 1 d of exposure but returned to the control values after 3 d of exposure. Red blood cell (RBC), white blood cell (WBC) and hemoglobin (Hb) levels were significantly increased throughout the experiment but returned to control values after 7 d of exposure only for the 0.1 mg/L concentration. The hematocrit (Ht) levels remained unaffected due to Hg exposure. Therefore, tilapias exposed to sublethal concentrations of Hg present a marked osmotic imbalance with ionic and hematological disorders that are rapidly compensated.