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| Costa,Silvio T. da; Gressler,Luciane T.; Sutili,Fernando J.; Loebens,Luíza; Lazzari,Rafael; Baldisserotto,Bernardo. |
| This study evaluates whether humic acid (HA; Aldrich) protects the silver catfish, Rhamdia quelen (Quoy & Gaimard, 1824), against exposure to acidic pH. Survival, levels of Na+, Cl- and K+ plasma, hematocrit, hemoglobin and erythrocyte morphometry were measured. Fish were exposed to 0, 10, 25 and 50 mg L 1 HA at four pH levels: 3.8, 4.0, 4.2 and 7.0 up to 96 hours. None of the fish exposed to pH 3.8 survived for 96 hours into the experiment, and survival of fish subjected to pH 4.0 decreased when HA concentration increased. Plasma Na+ levels decreased when pH was acidic, with no influence of HA, while Cl- levels declined at low pH with increased HA concentration. The levels of K+ at pH 4.0 and 4.2 increased without HA. Hematocrit and hemoglobin... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Blood parameters; Humic acid; Plasma ion levels; Survival. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702015000300215 |
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| Costa,Silvio Teixeira da; Sutili,Fernando Jonas; Gressler,Luciane Tourem; Loebens,Luíza; Colpo,Carine Vargas; Lazzari,Rafael; Baldisserotto,Bernardo. |
| ABSTRACT: Humic substances are organic compounds that possess high molecular weight and are formed by the decomposition of plant materials. Humic substances comprise humic acids, fulvic acids and humin. Humic acids (HA) have shown to be able to provide some protection to biological membranes of fish in water with low pH, replacing the protective action of Ca2+. Thus, this studyaimed to observe growth of silver catfish ( Rhamdia quelen ) juveniles exposed to pHs 5.5 and 6.5 and to different levels of HA: 0, 10, 25 and 50mg L-1. Results showed that, irrespective of pH, HA was highly detrimental to silver catfish growth, since the higher the concentration of HA, the lower the weight gain and feed intake, resulting in lower biomass and lower specific growth... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Humic substance; Water pH; Fish growth; Organic carbon. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016000601094 |
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