Stress in pacu exposed to ammonia in water

Abstract

-The present study evaluated stress indicators in pacu exposed to ammonia in water under the following conditions: without NH 4 Cl (0.00 g/L); with 0.0078 g NH 4 Cl/L; and with 0.078 g NH 4 Cl/L (pH 8.3 and 27 ºC). After the salt dilution the water flow was interrupted and reestablished in 24 hours. Sampling occurred prior to the addition of NH 4 Cl (control) and after 12, 24 and 48 hours. Glycaemia increased only in fish with the highest salt concentration when compared with group control, regardless of time, and at 24 hours, regardless of treatment. Plasma ammonia, highest in fish exposed to the highest NH 4 Cl concentration, decreased progressively up to 48 hours. Plasma chloride only decreased in fish not exposed to salt when compared with control and osmolality increased after 24 hours. Hematocrit (Ht), number and volume of erythrocytes and hemoglobin did not change when NH 4 Cl was added; Ht decrease was reported after 12 hours, but it was not followed by the other blood parameters. The results show tolerance of the pacu to ammonia in the environment.

Stress Tolerance of African Catfish (Clarias gariepinus, Burchell, 1822) Larvae Fed on Spirulina platensis or Eisenia fetida in Partial Replacement of Caridina nilotica in Formulated Diets

“…Generally, information on crustacean and general animals stress exists but it is yet to be extended to fish (Samocha et al, 1998;Abreu et al, 2012;Baßmann et al, 2017). Fish larvae stress information remains minimal because of limited data and lack of consensus from researchers on the assessment techniques to use in evaluating larval quality (Arizabal et al, 2009;Baßmann et al, 2017;Rehman et al, 2017;Liu et al, 2020).…”