Microcomputer‐based monitoring of the effect of phenol on electric organ activity in the mormyrid fish gnathonemus petersi

Abstract A microcomputer‐based monitoring system has been used to evaluate the effect of phenol solution on the electric organ discharges (EOD) of the elephant; fish Gnathonemus petersi (family: Mormyridae). Prior to experimentation, fish‐ are acclimatised for at least 48 h at 25°c. Using absolute calculations of phenol in the range 0–6 mgl−1, significant increases in the mean and variance of EOD, measured as pulses per min (PPM), are recorded with levels as low as 1 mgl”; within 30–90 min of dosing. At higher levels of 4–6 mgl−1, the increases in EOD are occasionally followed by a decrease during the period of dosing.