Fig 1.
A. Distribution of the different species of genus Pygocentrus modified from [48] and adapted with data from non-native populations [39–41,49]. The range of P. cariba is represented in black, that of P. nattereri is approximately divided into red and yellow according to the colouration of the belly and the river basins, and that of P. piraya is in blue. B. Locations of sampling sites (black stars) in Minas Gerais state, Brazil.
Table 1.
Specimens recorded in this study.
Fig 2.
A. Oscillogram and B. power spectrum of a sound with the features measured. d = duration, dez = duration of the energetic zone, p = period, pez = period in the energetic zone, F0 = fundamental frequency.
Fig 3.
Waveform (top) and spectrogram (bottom) of a sound produced by A. Pygocentrus cariba, B. Pygocentrus piraya. C. red-bellied Pygocentrus nattereri and D. yellow-bellied Pygocentrus nattereri. FFT Length: 512, window: Hamming, frame: 100%.
Fig 4.
Fundamental frequency as a function of the standard length for red-bellied Pygocentrus nattereri.
The three boxes show the data from [55]. Each box corresponds to the mean ± SD of a given size class. The green “■” are from [10] and the blue “♦” from this study. Linear regressions are presented for separated datasets and a polynomial model of all the data.
Table 2.
Adjustment models with their respective R2 for the fundamental frequency as a function of the standard length in red-bellied Pygocentrus nattereri.
Fig 5.
Comparison of the scores from principal component analysis (PCA) in the genus Pygocentrus.
Boxes represent the median ± interquartile range (IQR) and lines represent Q1–1.5 IQR and Q3 + 1.5 IQR. * = P < .05; ** = P < .01; *** = P < .001; Kruskal-Wallis + Dunn.
Fig 6.
Comparison of acoustic features of red and yellow-bellied Pygocentrus nattereri.
Boxes represent the median ± interquartile range (IQR) and lines represent Q1–1.5 IQR and Q3 + 1.5 IQR. ** = P < .01; *** P < .001; Wilcoxon-Mann-Whitney.
Table 3.
Scores of the Dunn post-hoc test on the principal components.
Significant P-values in red.