. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VISION IN THE LAND CRAB 403 . Gecarcmus lateralis i in CVJ 'EIO u CO z o I'll 0. 12 CO z LJ CO 13 Nomogram P440 G. late rails visual pigment. Dark-adapt Red-adapt oCs2-73 *6lOnm Blue-adapt • Cs5-€0 o440nm 350 400 450 500 550 600 650 WAVELENGTH (nm) FIGURE 3. Spectral sensitivity of the purple land crab compound eyes under dark- and chromatic adaptation conditions. Nomogram (Ebrey and Honig, 1977) for P440( • • •) and G. lateralis visual pigment ( ) from Figure 4 are superimposed for the data. spectra between bleaches and dar
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VISION IN THE LAND CRAB 403 . Gecarcmus lateralis i in CVJ 'EIO u CO z o I'll 0. 12 CO z LJ CO 13 Nomogram P440 G. late rails visual pigment. Dark-adapt Red-adapt oCs2-73 *6lOnm Blue-adapt • Cs5-€0 o440nm 350 400 450 500 550 600 650 WAVELENGTH (nm) FIGURE 3. Spectral sensitivity of the purple land crab compound eyes under dark- and chromatic adaptation conditions. Nomogram (Ebrey and Honig, 1977) for P440( • • •) and G. lateralis visual pigment ( ) from Figure 4 are superimposed for the data. spectra between bleaches and dark-adapted preparations of 13 individual photore- ceptors. The curve possesses a peak in the blue-green. The Dartnall (1953) nomogram curve for P487 nm closely matches this difference spectrum curve (Fig. 4). DISCUSSION The purple land crab Gecarcinus lateralis possesses a primary blue-green sensitive receptor system. This is supported by the following observations: (a) similarity of the ERG waveforms as a function of wavelength, (b) univariance of V/logI slopes as a function of wavelength (Fig. 1), (c) broad dark-adaptation curves with maximum in the blue-green (Fig. 3), (d) a lack of isolation of either blue or green receptor system under conditions of chromatic adaptation (Fig. 3), and (e) the presence of a blue- green absorbing (X max 487 nm) photopigment in the rhabdoms (Fig. 4). However this does not rule out the possibility of a second photoreceptor system, since it is possible that the contribution of a receptor type consisting of only few ommatidia can be masked by the dominant receptor system. In the retina of the swimming blue crab Callinectes sapidus, green-sensitive cells (X max 508 nm) were dominant, while only a few cells restricted to the ventral border region were blue-sensitive (X max 440. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illu
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
