Acute silver toxicity to Cnesterodon decemmaculatus (Pisces, Poecilidae) in the river with extrem water quality characteristics

CASARES, M. V; DE CABO, L; SEOANE, R; NATALE, O

ACTA TOXICOLóGICA ARGENTINA

ASOCIACIÓN TOXICOLÓGICA ARGENTINA

Lugar: Buenos Aires; Año: 2013 vol. 21 p. 93 - 101

0327-9286

 A 96 h acute silver toxicity test was performed in order to determine silver toxicity (LC ) to a local fsh species (Cnester- 50 odon decemmaculatus) in a river with extreme water-quality characteristics (Pilcomayo River, South America) and evaluate a cross-fsh-species extrapolation of the Biotic Ligand Model. The dissolved silver concentrations tested were 0.095, 0.148, 0.175  calculated for C. decemmaculatus was 0.14 mg L and 0.285 mg Ag L . The 96 h Ag LC  (0.18 - 0.10) and the value predicted −1 −1 50 by BLM for Pimephales promelas was 0.051 mg Ag L . Test water elevated hardness may have exerted some protective effect. −1 High mean water pH may have exerted a major protective effect by reducing silver free ion form and causing silver precipitation. The mortality pattern observed in this toxicity test may lend some support to a relationship between gill silver accumulation and mortality. A cross-fsh-species extrapolation of Ag BLM for P. promelas was not valid in Pilcomayo River water and experimental conditions of this toxicity test.