Fig. 3. Compiled electro-olfactogram (EOG) responses of goldfish to ascending concentrations of L-arginine, polyamines (putrescine, cadaverine and spermine) and single amine containing compounds (amylamine and butylamine). Responses were standardized to 0.1 mmol l^–1 L-arginine, which evoked a response of 0.4±0.2 mV (mean ± S.D.). Values are means ± S.E.M. 3–6 fish were tested for each concentration series. Putrescine, cadaverine and spermine evoked responses significantly greater than L-arginine at all tested odorant concentrations 10^–5 mol l^–1 (Student's t-test; P<0.05).