Resumen

CASARES, María Victoria; DE CABO, Laura I; SEOANE, Rafael  y  NATALE, Oscar. Acute silver toxicity to Cnesterodon decemmaculatus (Pisces: Poeciliidae) in a river with extreme water-quality characteristics. Acta toxicol. argent. [online]. 2013, vol.21, n.2, pp.93-101. ISSN 1851-3743.

Abstract. A 96 h acute silver toxicity test was performed in order to determine silver toxicity (LC₅₀) to a local fish species (Cnesterodon decemmaculatus) in a river with extreme water-quality characteristics (Pilcomayo River, South America) and evaluate a cross-fish-species extrapolation of the Biotic Ligand Model. The dissolved silver concentrations tested were 0.095, 0.148, 0.175 and 0.285 mg Ag L⁻¹. The 96 h Ag LC₅₀ calculated for C. decemmaculatus was 0.14 mg L⁻¹ (0.18 - 0.10) and the value predicted by BLM for Pimephales promelas was 0.051 mg Ag L⁻¹. Test water elevated hardness may have exerted some protective effect. 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-fish-species extrapolation of Ag BLM for P. promelas was not valid in Pilcomayo River water and experimental conditions of this toxicity test.

Palabras clave : Silver; Cnesterodon decemmaculatus; Biotic Ligand Model; Extrapolation.

        · resumen en Español     · texto en Inglés     · Inglés ( pdf )