Top row: Comparison between rms values of the head to tail electric organ discharge as measured in the same tank (45×26×4) at the same water conductivity and temperature.

Bottom row: the same individual values were normalized by the square of the fish's length according to the findings of Pereira et al [18]. Columns: median and interquartile range for each species. All these fish were recorded between 10 to 20 days after capture.