scholarly journals The Spectral Sensitivity of Crayfish and Lobster Vision

1961 ◽  
Vol 44 (6) ◽  
pp. 1089-1102 ◽  
Author(s):  
Donald Kennedy ◽  
Merle S. Bruno

(1) The spectral sensitivity function for the compound eye of the crayfish has been determined by recording the retinal action potentials elicited by monochromatic stimuli. Its peak lies at approximately 570 mµ. (2) Similar measurements made on lobster eyes yield functions with maxima in the region of 520 to 525 mµ, which agree well with the absorption spectrum of lobster rhodopsin if minor allowances are made for distortion by known screening pigments. (3) The crayfish sensitivity function, since it is unaffected by selective monochromatic light adaptation, must be determined by a single photosensitive pigment. The absorption maximum of this pigment may be inferred with reasonable accuracy from the sensitivity data. (4) The visual pigment of the crayfish thus has its maximum absorption displaced by 50 to 60 mµ towards the red end of the spectrum from that of the lobster and other marine crustacea. This shift parallels that found in both rod and cone pigments between fresh water and marine vertebrates. In the crayfish, however, an altered protein is responsible for the shift and not a new carotenoid chromophore as in the vertebrates. (5) The existence of this situation in a new group of animals (with photoreceptors which have been evolved independently from those of vertebrates) strengthens the view that there may be strong selection for long wavelength visual sensitivity in fresh water.

1959 ◽  
Vol 14 (4) ◽  
pp. 273-278 ◽  
Author(s):  
Jost Bernhard Walther ◽  
Eberhard Dodt

Behaviour experiments have shown that insects react to ultraviolet light. Almost no data are available within this spectral range, however, on the sensitivity of their light sense organs.In this investigation the relative spectral sensitivity (1/Q) of the compound eye of the fly, Calliphora erythrocephala, and various areas of the compound eye of the cockroach, Periplaneta americana, was measured including the ultraviolet range down to 290 mμ. Equal amplitudes of the electroretinogram indicated equal efficiencies of the stimuli.The sensitivity curve in both species shows, besides the known maximum in the blue green, a second maximum in the ultraviolet. This second maximum was found between 341-369 mμ depending on the species and the particular area of the eye. At still shorter wave lengths sensitivity decreases. In the fly eye and the upper part of the cockroach eye the sensitivity maximum in the ultraviolet is higher than in the bluegreen, whereas in the ventral part of the cockroch eye it is lower. Monochromatic light adaptation selectively influences the relative sensitivity of the upper part of the cockroach eye.The sensitivity curves are discussed with regard to visual pigments and types of receptors. Fluorescence of the eye media is considered to have only negligible if any influence on the high sensitivity for ultraviolet light.


1990 ◽  
Vol 45 (1-2) ◽  
pp. 137-142 ◽  
Author(s):  
Eric J. Warrant ◽  
Robert B. Pinter

Abstract Intracellular recordings of angular sensitivity from the photoreceptors of Aeschnid dragonflies (Hemianax papuensis and Aeschna brevistyla) are used to determine the magnitude and time course of acuity changes following alterations of the state of light or dark adaptation. Acuity is defined on the basis of the acceptance angle, Δρ (the half-width of the angular-sensitivity function). The maximally light-adapted value of Δρ is half the dark-adapted value, indicating greater acuity during light adaptation. Following a change from light to dark adaptation, Δρ increases slowly, requiring at least 3 min to reach its dark-adapted value. In contrast, the reverse change (dark to light) induces a rapid reduction of Δρ , and at maximal adapting luminances, this reduction takes place in less than 10 sec.


1967 ◽  
Vol 50 (9) ◽  
pp. 2267-2287 ◽  
Author(s):  
Robert M. Chapman ◽  
Abner B. Lall

Electrical responses (ERG) to light flashes of various wavelengths and energies were obtained from the dorsal median ocellus and lateral compound eye of Limulus under dark and chromatic light adaptation. Spectral mechanisms were studied by analyzing (a) response waveforms, e.g. response area, rise, and fall times as functions of amplitude, (b) slopes of amplitude-energy functions, and (c) spectral sensitivity functions obtained by the criterion amplitude method. The data for a single spectral mechanism in the lateral eye are (a) response waveforms independent of wavelength, (b) same slope for response-energy functions at all wavelengths, (c) a spectral sensitivity function with a single maximum near 520 mµ, and (d) spectral sensitivity invariance in chromatic adaptation experiments. The data for two spectral mechanisms in the median ocellus are (a) two waveform characteristics depending on wavelength, (b) slopes of response-energy functions steeper for short than for long wavelengths, (c) two spectral sensitivity peaks (360 and 530–535 mµ) when dark-adapted, and (d) selective depression of either spectral sensitivity peak by appropriate chromatic adaptation. The ocellus is 200–320 times more sensitive to UV than to visible light. Both UV and green spectral sensitivity curves agree with Dartnall's nomogram. The hypothesis is favored that the ocellus contains two visual pigments each in a different type of receptor, rather than (a) various absorption bands of a single visual pigment, (b) single visual pigment and a chromatic mask, or (c) fluorescence. With long duration light stimuli a steady-state level followed the transient peak in the ERG from both types of eyes.


1993 ◽  
Vol 10 (3) ◽  
pp. 523-527 ◽  
Author(s):  
H.-J. Wagner ◽  
D. Kath ◽  
R.H. Douglas ◽  
M. Kirsch

AbstractIn a dichromatic teleost species, we determined the intensity of light of various wavelengths required to prevent cone elongation by exposing fish at the time of their normal “dusk” phase to monochromatic light (479, 623, and 660 nm) at eight to ten different intensities for 75 min. The positions of single and double cones were measured in tangential sections and expressed as cone indices. At all wavelengths, the spectral responses of both cone types were virtually identical. Furthermore, the sensitivity of the blocking effect was highest at shorter wavelengths. When comparing the relative quantal sensitivities of myoid elongation for the two cone types to the spectral sensitivities of the three types of Aequidens pulcher photoreceptor, we found the closest match between the action spectrum and the absorption spectrum of the green-sensitive single cones. This may indicate that this cone type is capable of reacting directly to decreasing levels of illumination. On the other hand, the identical sensitivity of both cone types argues for an indirect control mechanism of dark-adaptive cone elongation, possibly via a neural pathway involving the inner retinal layers, complementary to the neural control of light adaptation. Green-sensitive single cones are well suited to trigger this response, since (1) their sensitivity is inferior to that of double cones; (2) waters inhabited by the blue acara transmit best at long wavelengths; and (3) at dusk, long-wavelength radiation dominates over other parts of the spectrum. Therefore, green-sensitive cone threshold will be reached first at dusk.


1998 ◽  
Vol 15 (4) ◽  
pp. 643-651 ◽  
Author(s):  
JEFFRY I. FASICK ◽  
THOMAS W. CRONIN ◽  
DAVID M. HUNT ◽  
PHYLLIS R. ROBINSON

To assess the dolphin's capacity for color vision and determine the absorption maxima of the dolphin visual pigments, we have cloned and expressed the dolphin opsin genes. On the basis of sequence homology with other mammalian opsins, a dolphin rod and long-wavelength sensitive (LWS) cone opsin cDNAs were identified. Both dolphin opsin cDNAs were expressed in mammalian COS-7 cells. The resulting proteins were reconstituted with the chromophore 11-cis-retinal resulting in functional pigments with absorption maxima (λmax) of 488 and 524 nm for the rod and cone pigments respectively. These λmax values are considerably blue shifted compared to those of many terrestrial mammals. Although the dolphin possesses a gene homologous to other mammalian short-wavelength sensitive (SWS) opsins, it is not expressed in vivo and has accumulated a number of deletions, including a frame-shift mutation at nucleotide position 31. The dolphin therefore lacks the common dichromatic form of color vision typical of most terrestrial mammals.


1992 ◽  
Vol 8 (3) ◽  
pp. 243-249 ◽  
Author(s):  
Joseph C. Besharse ◽  
Paul Witkovsky

AbstractTo test the hypothesis that light-evoked cone contraction in eye cups from Xenopus laevis is controlled through a direct mechanism initiated by the cone's own photopigment, we conducted spectral-sensitivity experiments. We estimate that initiation of contraction of red absorbing cones (611 nm) is 1.5 log units more sensitive to green (533 nm) than red (650 nm) light stimuli. The difference is comparable to that predicted from the spectral-sensitivity function of the green absorbing, principal rod (523 nm). Furthermore, 480-nm and 580-nm stimuli which are absorbed nearly equally by the principal rod have indistinguishable effects on cone contraction. We also found that light blockade of nighttime cone elongation is much more sensitive to green than to red light stimuli. Our observations are inconsistent with the hypothesis tested, and suggest that light-regulated cone motility is controlled through an indirect mechanism initiated primarily by the green absorbing, principal rod.


1995 ◽  
Vol 198 (9) ◽  
pp. 1909-1917 ◽  
Author(s):  
D Cutler ◽  
R Bennett ◽  
R Stevenson ◽  
R White

The spectral sensitivity of nectar feeding by adults of the tobacco hawkmoth Manduca sexta was measured in free-choice experiments. The action spectrum displayed a narrow peak at 450 nm and a low secondary maximum at 560 nm. Thus, the feeding response is mediated primarily by blue-sensitive receptors containing the Manduca sexta photopigment P450, while green-sensitive receptors containing P520 play a minor role. A minimum at 500 nm separating the two peaks suggests mutual inhibition between green and blue receptors or negative interaction more proximally in the visual system. The action spectrum drops off abruptly at 400 nm, in accordance with an earlier finding that ultraviolet wavelengths, discerned by receptors containing P357, obstruct the feeding response. The spectral sensitivity of the Manduca sexta compound eye, determined by electroretinogram recordings, and earlier visual pigment measurements indicate that approximately 75 % of the receptors are green-sensitive, with the remainder divided between blue- and ultraviolet-sensitive cells. The distribution of receptor types in small areas of the retina was measured by their ultrastructural response to light. Green and ultraviolet receptors were found, but not the blue receptors that dominate the feeding response. Possibly they are concentrated in a particular region of the retina that has not yet been found.


1996 ◽  
Vol 86 (4) ◽  
pp. 337-342 ◽  
Author(s):  
P.E. Brown ◽  
M. Anderson

AbstractThe spectral sensitivity of the compound eye of the cabbage root fly, Delia radicum (Linnaeus), was measured using the electroretinogram (ERG) technique, at fifteen selected wavelengths between 340 nm and 670 nm. The form of the ERG was found to be diphasic in nature. A primary peak of spectral sensitivity in the UV (340–350 nm), and a smaller secondary peak in the blue-green region (460–546 nm) were found, together with a shoulder of sensitivity, representing a ‘pseudo-peak’ as reported for other Diptera, in the red region (630 nm). No significant differences were found between the dorsal and ventral regions of the eye. The peak response in the green region (546 nm) agrees well with existing behavioural data on colour attraction and visual discrimination of host plants by the cabbage root fly.


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