Abstract
The objective of this study was to evaluate the tolerance of piavas (Leporinus obtusidens) to ammonia (NH3) by measuring its effects on plasma ion levels and tissue metabolic parameters. Piava juveniles (25-30 g) were exposed to five concentrations of NH3 (mg L-1): 0.003 (control), 0.1, 0.4, 0.7, and 1.4; after 96 hours, plasma levels of Na+, K+, Cl- and NH4+ ions and metabolic and enzyme activity in tissues (liver, kidneys, gills and muscle) were measured. The lethal concentration (LC50; 96h) of NH3 was 0.27 mg L-1. As NH3 increased, Na+ and NH4+ in the plasma increased and K+ decreased. In addition, Na+/K+- ATPase activity concomitantly increased in the gills and decreased in the kidneys. Glucose, glycogen, and protein levels decreased, while lactate and ammonia increased in the tissues of piava juveniles that were treated with higher concentrations of ammonia. The observed lethal toxicity could be due to a gradual depletion of plasma ion levels and a reduction of metabolic and Na+/K+-ATPase activity in tissues. Both can lead to dysfunction in ionoregulatory and physiological systems. This finding has implications for the management of fish culture of piavas.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
