Open AccessSecondary Stress Responses in Juvenile Brazilian Flounder, Paralichthys orbignyanus , throughout and after Exposure to Sublethal Levels of Ammonia and Nitrite
Author(s) -
C. Maltez Lucas,
L. Barbas Luis A.,
H. Okamoto Marcelo,
L. de Alcantara Lopes Diogo,
Romano Luis A.,
Sampaio Luís A.,
Garcia Luciano
Publication year - 2019
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/jwas.12497
Subject(s) - nitrite , ammonia , biology , olive flounder , flounder , zoology , medicine , endocrinology , biochemistry , fishery , fish <actinopterygii> , ecology , nitrate
This study investigated the secondary stress responses of Paralichthys orbignyanus exposed to ammonia and nitrite and after recovery. Fish were exposed to 0.12, 0.28, and 0.57 mg NH 3 ‐N/L, or 5.72, 10.43, and 15.27 mg NO 2 ‐N/L for 10 d followed by the same time length for recovery. Ammonia‐ and nitrite‐free water was used as a control treatment. Blood samples were collected after 1, 5, and 10 d of exposure and after recovery. Fish exposed to ammonia presented lower and higher glucose levels after 10 d of exposure and recovery, respectively. Ammonia induced initial and transient ionic disturbances and metabolic alkalosis. Nitrite exposure caused hyperglycemia, increased plasma K + levels, and respiratory alkalosis, whereas metabolic acidosis was observed after recovery. Increased proportion of monocytes and/or granulocytes and reduced number of lymphocytes were demonstrated in fish exposed to 0.28 mg NH 3 ‐N/L (Day 1) and 10.43 mg NO 2 ‐N/L (Day 5) and after recovery in the 0.28 and 0.57 mg NH 3 ‐N/L treatments. Exposure to ammonia decreased the proportion of granulocytes on Day 5. In conclusion, exposure to concentrations at 0.12 mg NH 3 ‐N/L and 5.72 mg NO 2 ‐N/L provoked physiological disorders in Brazilian flounder. Nonetheless, fish exposed to 5.72 mg NO 2 ‐N/L following a 10‐d recovery period showed complete resumption of homeostasis.