| Little information is available about natural populations of fishes exposed to polluted waters in Brazil. Contaminants may be lethal or predispose fishes to sickness, being the analysis of aquatic organisms a good indicator of environmental quality. The violinha, Rineloricaria strigilata (Hensel, 1868), is a common loricariid catfish in the Guaíba lake basin, Rio Grande do Sul, Brazil, and has been selected as a bioindicator for being resident, occurring in more than 50% of the samples, and by showing externally detectable neoplasies. These are characterized by its dark pigmentation, bony plates hypertrophy, and hypertrophy and irregular arrangement of the odontodes. Histology showed hypertrophied epitelial tissues, with an increased number of secretory... |
