POSTNER, M and KRAMER, B (1995) ELECTROSENSORY THRESHOLDS IN LARVAE OF THE WEAKLY ELECTRIC FISH POLLIMYRUS-ISIDORI (MORMYRIDAE, TELEOSTEI) DURING ONTOGENY. JOURNAL OF EXPERIMENTAL BIOLOGY, 198 (3). pp. 783-791. ISSN 0022-0949,
Full text not available from this repository.Abstract
Electrosensory thresholds and tuning were determined from behavioural studies in larvae of Pollimyrus isidori using the stop response of their electric organ discharge to weak electrical stimuli. Two age groups were studied: (1) 10- to 15-day-old larvae in which the electric organ discharge (EOD), produced by a distinct larval electric organ, had just stabilized; (2) 54- to 60-day-old larvae, just before the advent of the adult EOD (an adult electric organ functionally replaces that of the larva between about 60 and 80 days). Three stimulus pulse waveforms were used: (1) single-cycle, bipolar sine-wave pulses; (2) single-cycle, monopolar sine-wave pulses and (3) monopolar square-wave pulses. The younger larvae were exceedingly sensitive to weak electrical stimuli, down to the 10 mu V(p-p)cm(-1) range. Stimulus pulse duration had a significant effect on threshold for all three pulse waveforms, but the shapes of the tuning curves were quite different. Thresholds at the 'best' pulse duration were lower and the tuning sharper (with a V-shaped curve) with monopolar sine-wave pulses than with bipolar sine-wave pulses. The 'best' pulse duration was 1 ms for both sine-wave pulses, corresponding well to the spectral peak amplitude of larval EODs (964+/-22 Hz). The threshold curve for monopolar sine-wave pulses appeared to be perfectly adapted for sensing larval rather than adult EODs. With square-pulse stimuli, thresholds increased monotonically with duration and there was no evidence of tuning for this kind of stimulus. These results suggest that both conventional spectral
| Item Type: | Article |
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| Uncontrolled Keywords: | JAMMING AVOIDANCE-RESPONSE; EIGENMANNIA; ELECTRORECEPTORS; COMMUNICATION; GYMNOTIFORMES; REPRODUCTION; SYSTEM; ELECTROSENSORY THRESHOLDS; ELECTROSENSORY TUNING; WEAKLY ELECTRIC FISH; KNOLLENORGAN; FISH LARVAE; ONTOGENY; MORMYRIDAE; POLLIMYRUS ISIDORI |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:38 |
| URI: | https://pred.uni-regensburg.de/id/eprint/52722 |
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