. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VISION IN THE LAND CRAB 401 60Or 500 UJ Q P 300 200 100 0. LOG INTENSITY (photons /cm2s) FIGURE 1. V/logI curves for a dark-adapted compound eyes in Gecarcinns lateralis. The number at the bottom of the curve is the log photons for the lowest response. Note that the curves for different wave- lengths are similar in slope. RESULTS Electroretinograms (ERGs) The ERGs were recorded from the corneal surface of the compound eyes after an initial latency period (20-60 ms) from the onset of illumination. The response was an &
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VISION IN THE LAND CRAB 401 60Or 500 UJ Q P 300 200 100 0. LOG INTENSITY (photons /cm2s) FIGURE 1. V/logI curves for a dark-adapted compound eyes in Gecarcinns lateralis. The number at the bottom of the curve is the log photons for the lowest response. Note that the curves for different wave- lengths are similar in slope. RESULTS Electroretinograms (ERGs) The ERGs were recorded from the corneal surface of the compound eyes after an initial latency period (20-60 ms) from the onset of illumination. The response was an "on" negative potential consisting of an initial phasic component followed by a maintained or plateau component which lasted for the total duration of the illumina- tion. At low levels of illumination only the plateau component was recorded. The phasic component appeared at the intermediate levels of the illumination and in- creased sharply with bright illumination. The "on" negative ERGs in the land crab were similar to the ones recorded from the compound eyes of many arthropods which have scotopic eyes (, horseshoe crab; Chapman and Lall, 1967; Crustacea; Wald, 1968). The response waveform of the ERGs elicited by the stimuli of different wave- lengths tended to be similar. Intensity-response (V/log I) functions Figure 1 shows the amplitude of the phasic component of the ERG plotted as a function of log intensity of the stimuli of different wavelengths and intensities. The slopes of these V/logI functions for the phasic components did not vary with stimulus wavelength. These V/logI curves were used for: (a) determining the spectral sensitivi- ties in Figure 3 (only the DA curve) and (b) determining whether there were any wavelength-dependent changes in the slope of the V/logI functions. Systematic changes in the slopes of the response curves for different wavelengths have been taken as evidence for the presence of different receptor types as in the media
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
