Open AccessAmmonia‐, Sodium Chloride‐, and Calcium Sulfate‐induced Changes in the Stress Responses of Jundiá, Rhamdia quelen , Juveniles
Author(s) -
Carneiro Paulo César Falanghe,
Swarofsky Elaine Correa,
Souza Daniana Pinotti E.,
César Thiago Mocelin Ramos,
Baglioli Bárbara,
Baldisserotto Bernardo
Publication year - 2009
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/j.1749-7345.2009.00302.x
Subject(s) - ammonia , gypsum , zoology , sodium , biology , calcium , chloride , aqueous solution , salt (chemistry) , endocrinology , medicine , chemistry , biochemistry , paleontology , organic chemistry
Salt (NaCl) and gypsum (CaSO 4 ) are used as water additives to mitigate fish stress and improve specimen survival. High stocking densities and the transportation of fish can increase aqueous ammonia, which can, in turn, alter fish cortisol secretion. The objectives of this study were to assess the effects of salt, gypsum, and aqueous ammonia on some stress‐induced physiological responses of jundiá, Rhamdia quelen , juveniles induced by captivity and handling, and to determine the lethal ammonia concentration for this species. Jundiá juveniles were subjected to the following five treatments: water only, water + ammonia (0.4 mg/L), water + NH 3 + NaCl (6 g/L), water + NH 3 + gypsum (150 mg/L), and water + NH 3 + NaCl + gypsum. Blood samples were taken after intervals of 1, 5, 24, and 96 h, and the concentrations of cortisol, glucose, chloride, ammonia, and hematocrit were determined. The NH 3 LC 50 value after 96 h of exposure (LC 50−96h ) was measured to be 1.9 mg/L NH 3 . Either salt or gypsum reduced both cortisol and glucose levels during most of the experimental period, but the combination of both reduced these levels even further. The combined use of NaCl and CaSO 4 demonstrates a synergic effect on mitigating stress responses induced by handling and aqueous ammonia in jundiá juveniles.