WEIGHT-LENGTH AND RELATIVE CONDITION FACTOR OF Bryconamericus iheringii IN STREAMS OF THE PARANAPANEMA RIVER, BRAZIL

Abstract

Relationship weight-length and the Relative Condition Factor (Kn) of fish species Bryconamericus iheringii were analyzed. Fish were captured in three streams of the Cinzas River basin, high river Paraná, to determine growth rate and well-being of populations. Analyses of Variance (Unifactorial ANOVA) verified significant differences in weight, length and Kn between streams, whereas Spearman correlation analyses indicated the relationship between the above mentioned parameters and physical and chemical factors and population density in the streams. Specimens from the stream Ubá, the most preserved stream among the three analyzed with regard to riparian vegetation, had greater weight, length and Kn. Specimens from streams Água dos Anjos and Monjolinho showed negative allometric growth, with greater increase in length (mm), whereas specimens from the stream Ubá had positive allometric growth, with greater increase in weight (g). Kn was co-related (p<0.05) negatively with density and conductivity. Low conductivity was co-related with high extension of riparian vegetation. Current analysis reveals that parameters for weight-length and Kn in stream fish specimens may be affected significantly by environmental characteristics, mainly related to bank vegetation. They may be good complementary measures for responses of organisms to anthropic changes.