Tolerance of piava juveniles to different ammonia concentrations
DOI:
https://doi.org/10.5433/1679-0359.2015v36n6p3991Keywords:
Ionoregulatory, Lethal concentration, Na /K -ATPase.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.
Downloads
Downloads
Published
How to Cite
Issue
Section
License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Semina: Ciências Agrárias adopts the CC-BY-NC license for its publications, the copyright being held by the author, in cases of republication we recommend that authors indicate first publication in this journal.
This license allows you to copy and redistribute the material in any medium or format, remix, transform and develop the material, as long as it is not for commercial purposes. And due credit must be given to the creator.
The opinions expressed by the authors of the articles are their sole responsibility.
The magazine reserves the right to make normative, orthographic and grammatical changes to the originals in order to maintain the cultured standard of the language and the credibility of the vehicle. However, it will respect the writing style of the authors. Changes, corrections or suggestions of a conceptual nature will be sent to the authors when necessary.
