Psychophysical assessment of catfish electro-sensitivity versus temperature and electric field frequency
Peters, R.C.; Loos, W.J.G.; Bretschneider, F.; Heijmen, P.S. (1995). Psychophysical assessment of catfish electro-sensitivity versus temperature and electric field frequency. Neth. J. Zool. 45(1-3): 347-361
In: Netherlands Journal of Zoology. E.J. Brill: Leiden. ISSN 0028-2960; e-ISSN 1568-542X, more
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| Authors | | Top |
- Peters, R.C.
- Loos, W.J.G.
- Bretschneider, F.
- Heijmen, P.S.
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| Abstract |
The detection thresholdof the electrosensory system in catfish, Ictalurus nebulosus, was assessed psychophysically with the 'staircase method' in two-alternative forced-choice experiment over a period of 6 months.Detection tresholds were assessed at stimulus frequencies of 0.03, 0.1, 1, 3, 10, 30, and 100 Hz at temperatures of 5, 10, 15, 20, and 25 °C. The water conductivity was kept between 0.23 and 0.27 mS/cm. The behavioural response curve hass a band pass filter shape with maximum transfer at frequencies in the range from 1 to 3 Hz. The lowest value of the treshold was 0.8 µV/cm at 1 Hz, 25°C, and 0.26 mS/cm. At lower frequencies, e.g. 0.03 Hz, the mean trashold ranged from 500 to 1000 µV/cm. The overall preformance of the fish improved during the course of the experiment as was demonstrated by the mean treshold at 1 Hz from 35 to 10 µV/cm. Treshold-temperature curves were incongruous with electro-physiologicallymade sensitivity recordings of electroreceptor organ primary afferents. At frequencies above 3 Hz temperature effects were most noticeable, mainly as an increased sensitivity. Temperature effects at frequencies less than 3 Hz were negligible. The results serve as reference values for future studies on water pollution where the electric sense serves as a biomonitor system. We conclude that such stdies should be conducted at stimulus frequencies between 0.1 and 3 Hz. |
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