Fig. 2. Sampling method applied to capture Lithodoras dorsalis at the Amazon River mouth, Brazil, from July 2010 to June 2011. a. Net set at the bottom during the dusk and with low tide to allow the fish entrance in small rivers; b. Net lifted during the next morning (approximately, 12 hours after setting at the bottom), blocking the exit of fishes that came during the night; c and d. Fish sample using seine nets and hand- or dip-nets.