Fig. 4. Temperature sensitivity of EOD waveform. (A) Recordings of EOD waveform at 20°C (black) and after 30 min at 30°C (red) in males with high (left) and low (right) temperature sensitivity. Fish with high temperature sensitivity lose their negative component (P2) at 30°C whereas the amplitude of the negative component is not different at 20° and 30°C in fish with low temperature sensitivity. (B,C) Temperature sensitivity is inversely correlated to gonadal stages of maturity. Stage 1, regressing/resting; stage 2, recovering; stage 3, maturing; stage 4, mature. TS index is high in males and females that present resting gonads and low in fish with mature gonads (Mann–Whitney test, P<0.05; n₁=4, n₂=4).