Alterações histológicas em placas ósseas do peixe cascudo Rineloricaria strigilata (Hensel) (Teleostei, Loricariidae) e sua freqüência no lago Guaíba, Rio Grande do Sul, Brasil

Abstract

Description of histological abnormalities in lhe bony plates of the loricariid catfish Rilleloricaria slrigi/ala (Hensel) (Teleostei, Loricariidae) and analysis of its frequeney in the lake Guaíba, Rio Grande do Sul, Bl'azil. Lirrle informarion is available abour natural populations oftishes exposed to polluted waters in Brazil. Contaminanls may be lethal or predispose jishes lo siekness, being lhe analysis ofaquatic organisms a good indicaror 01' environmental quality. The violinha, Rine/oricaria slrigi/ala (Hensel, 1868), is a common loricariid calfish in the Guaíba lake basin, Rio Grande do Sul, Brazil, and has been seleeted as a bioindieator for being resident, occwTing in more than 50% of lhe samples. and by showing externally detectable neoplasies. These are characterized by its dark pigmenlation, bony plates hypertrophy, and hypertrophy and irregular arrangemenl ofthe odonlodes. Ilislology showed hypertrophied epitelial tissues, with an increased number of secretOlY cells, blood cells, and melanina pigmenrs, giving the dark appearanee to the neoplasm. Observed JI'equeneies of neoplasm were higher in lake Guaíba lhan in eomparative samples. Inside lake Guaíba, a pattem ofdistribution ofneoplasm was observed, with rhe absence of neoplasm in tishes at the eollecred sire rhat receives warer from rio Jacuí, and frequencies of3.04 to 16.81% in the collecrion localities in ti"onr ofPorto Alegre and downstreamlocalities, that receive water from rio JacuÍ, rio dos Sinos and rio Gravataí, that drain urban and industrial area of POIio Alegre and neighborhood ciries.

Diet and capture of Hypostomus strigaticeps (Siluriformes, Loricariidae) in a small brazilian stream: relationship with limnological aspects

“…This possibility, however, would require a separate study since it lay outside the scope of this one. This hypothesis may be corroborated by other researchers who, upon examining the effects of water quality on another armored catfish, discovered a direct relationship between the level of water pollution and the occurrence of wounds and histopathological alterations affecting fish health (Flores-Lopes et al, 2001). In addition, fish affected by dysplasia showed lower survival chances, and were more easily eliminated from the population (Bergman, 1985).…”

Effects of bacterial infestation caused by human wastes on the skin structures of Mugil platanus Günther, 1880 (Mugilidae)

“…Since diseases caused by bacteria originated from human activity are affecting the juveniles of this species, this can compromise the maintenance of fish stocks in the estuary. Flores-Lopes et al (2001;2002) used the presence of lesions/anomalies in fish species as an instrument of biological evaluation of environmental quality. The results obtained in our study with Mugil platanus specimens, re- assure the importance of using anomalies as indicators of environmental alterations and degradations of anthropic origin which compromise the quality of ecosystems.…”

Chromosomal banding in three species of the genus Rineloricaria (Siluriformes, Loricariidae, Loricariinae)

“…They are widely distributed from Costa Rica to La Plata River, Argentina, demonstrating large adaptive diversity and exploiting a wide range of habitats (Ferraris 2007). Some species, such as Rineloricaria strigilata, are found in many polluted environments, demonstrating ichthyological diversity in various habitats (Flores-Lopes et al 2001).…”