Figure 2. (A) Schematic drawing of the sagitta otolith of Centropomus undecimalis and Centropomus ensiferus caught in the lower São Francisco River, Sergipe, Brazil; (B) Contour of the otolith using 512 equidistant coordinates in the sagitta otolith; Abbreviations: A = anterior region, D = dorsal region, V = ventral region, P = posterior part of the otolith, AS = sulcus acusticus, r = rostrum and e = excisura.