title: Laser-induced fluorescence in fish scales to evaluate the environmental integrity of ecosystems.
abstract: The aim of this study was to evaluate the fluorescence of Astyanax lacustris fish scales when excited in the UV-A and blue regions for use as a bioindicator of aquatic ecosystems. This species was firstly defined as Astyanax altiparanae, popularly known as "lambari-do-rabo-amarelo". Currently, abiotic/biotic environmental integrity is generally assessed using limnological and physicochemical parameters related to biological indicators in streams or rivers, which are not sufficient to evaluate the real environmental conditions: in some cases, these parameters can be strongly dependent on local weather conditions. In this study, after the fish scales were excited with UV-A (360nm) and blue (405nm) photons, a strong and broad visible fluorescence band (from blue to red) could be observed that was mainly related to collagen and hydroxyapatite, independent of whether the excitation was applied to the inside or outside of the scale. Selected emission wavelengths were used as variables and the fluorescence intensities were interpreted using multivariate discriminant statistical analysis to compare streams with known different levels of integrity. The fluorescence data showed strong correlation with the electrical conductivity of the water, indicating that the scales of A. lacustris could be employed as bioindicators of environmental integrity on water chemistry monitoring programs.
authors: Programa de Pós-Graduação em Recursos Naturais, Universidade Estadual de Mato Grosso do Sul, C.P. 351, Dourados, MS, Brazil.
authors: Cristiane Ávila
authors: CÁ
authors: Santana
authors: Programa de Pós-Graduação em Recursos Naturais, Universidade Estadual de Mato Grosso do Sul, C.P. 351, Dourados, MS, Brazil.
authors: Dinorah Machado Vaz
authors: DM
authors: Lima
authors: Programa de Pós-Graduação em Recursos Naturais, Universidade Estadual de Mato Grosso do Sul, C.P. 351, Dourados, MS, Brazil.
authors: Luis Humberto
authors: LH
authors: da Cunha Andrade
authors: Programa de Pós-Graduação em Recursos Naturais, Universidade Estadual de Mato Grosso do Sul, C.P. 351, Dourados, MS, Brazil.
authors: Yzel Rondon
authors: YR
authors: Súarez
authors: Programa de Pós-Graduação em Recursos Naturais, Universidade Estadual de Mato Grosso do Sul, C.P. 351, Dourados, MS, Brazil. Electronic address: smlima@pesquisador.cnpq.br.
authors: Sandro Marcio
authors: SM
authors: Lima
mesh_terms: D000818:Animals; D017753:Ecosystem; D005399:Fishes; D005453:Fluorescence; D005618:Fresh Water; D007834:Lasers; D013050:Spectrometry, Fluorescence
keywords: Astyanax lacustris; Bioindicators; Collagen emission; Electrical conductivity of water; Fluorescence spectroscopy