A new mechanism for light-dark adaptation in theArtemia compound eye (Anostraca, Crustacea)

1981 ◽  
Vol 143 (3) ◽  
pp. 389-399 ◽  
Author(s):  
Dan-Eric Nilsson ◽  
Rolf Odselius
Keyword(s):  
Dark Adaptation ◽  
Compound Eye

Changes of Acuity during Light and Dark Adaptation in the Dragonfly Compound Eye

1990 ◽  
Vol 45 (1-2) ◽  
pp. 137-142 ◽  
Author(s):  
Eric J. Warrant ◽  
Robert B. Pinter
Keyword(s):  
Dark Adaptation ◽  
Time Course ◽  
Light Adaptation ◽  
Compound Eye ◽  
Sensitivity Function ◽  
The State ◽  
Intracellular Recordings ◽  
Acceptance Angle ◽  
Angular Sensitivity ◽  
Rapid Reduction

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.

Adaptation in the Compound Eye and Interaction with Screening Pigment

1972 ◽  
Vol 56 (1) ◽  
pp. 119-128
Author(s):  
U. YINON
Keyword(s):  
Dark Adaptation ◽  
Light Adaptation ◽  
Compound Eye ◽  
Electrical Response ◽  
Negative Potential ◽  
Neural Pathways ◽  
Photochemical Process ◽  
Screening Pigment ◽  
The Difference ◽  
Adaptation Processes

The electroretinogram pattern in the compound eye of T. molitor and the appearance of irregular small potentials and spikes superimposed on the ERG are influenced during dark and light adaptation procedures. The amplitude of the principal negative potential reflects bleaching and recovery of the photochemical process. This is not true for the latency values. The delay of the electrical response increases in the dark and decreases in the light adapted eye. These changes were influenced by the intensity of the adapting light. Mutant eyes only lack screening pigment and have normal visual neural pathways. The absence of this pigment lowered the threshold sensitivity of the unscreened eye in dark adaptation. The difference between the adaptation processes in mutants and normal animals has been suggested as a criterion for measuring the net effect of the screening pigment in the compound eye.

The eye of Anoplognathus (Coleoptera, Scarabaeidae)

1975 ◽  
Vol 188 (1090) ◽  
pp. 1-30 ◽  
Keyword(s):  
Refractive Index ◽  
Point Source ◽  
Dark Adaptation ◽  
Compound Eye ◽  
Visual Fields ◽  
Optomotor Response ◽  
Clear Zone ◽  
Acceptance Angle ◽  
Single Plane ◽  
Receptor Layer

The night flying scarabaeid beetle Anoplognathus provides an example of a dark-adapted clear-zone compound eye in which rays from a distant point source, entering by a large patch of facets, are imperfectly focused upon the receptor layer. The optical system of the eye was investigated by six methods, all of which give similar results: (1) ray tracing through structures of known refractive index, (2) measurement of visual fields of single receptors, (3) measurement of the divergence of eyeshine, and (4) of the optomotor response to stripes of decreasing width, and (5) by direct observation of distribution of light within the eye. Finally (6) anatomically there is no single plane upon which an image could be focused. In each ommatidium, beneath the thick cornea, with its short corneal cone, lies a non-homogeneous crystalline cone (range of r. i. 1.442-1.365) that is significant in partially focusing rays across the wide clear zone (340 μm) in the dark-adapted eye. On the proximal side of the clear zone the rhabdoms form 7-lobed columns, isolated from each other over half their length by a tracheal tapetum. In the light-adapted eye the cone cells extend to form a crystalline tract (70-90 μm long) which is sur­rounded by dense pigment, and the optical path across the clear zone is completed by retinula cell columns that are of higher density than the surrounding cells. Pigment movement upon adaptation takes about 10 min to complete. Dark adaptation can be induced only at night on account of a strong diurnal rhythm. Eyeshine can be seen in the dark-adapted eye so long as the distal pig­ment leaves free the tips of the crystalline cones. Eyeshine falls to 50% at an angle of 12° from the direction of a parallel beam shining on the eye, as is consistent with a partial focus in which the distribution of light on the receptor layer is 18°-24° wide at the 50% contour. This distribution was confirmed by direct examination of the inside of the eye and by measure­ment of receptor fields as follows. The mean acceptance angle for 13 light-adapted units was 12.57° ± 1.97° s. d. and that of 10 dark-adapted ones 20.3° ± 3.36° s. d. The sensi­tivity to a point source on axis is increased at least 1000 fold by dark adaptation. Rays traced through a scale drawing of the eye, with refractive index measured for each component, show how the eye as a whole comes to be partially focused, and predicts an acceptance angle of 12° in the light-adapted and 20°-24° in the dark-adapted eye. In optomotor experiments dark-adapted Anoplognathus does not respond to stripes narrower than 18° repeat period, but light-adapted beetles respond down to 10°. The optomotor experiments also show a 1000 fold increase in sensitivity when dark-adapted at night. The eye has poor acuity that goes with wide visual fields of its recep­tors, and this is surprising when other excellently focused clear zone eyes are known. A possible compensation for the poor acuity is that the aperture of the eye can be larger, so that sensitivity although only to large objects, is that much increased.

Effect of light and dark adaptation upon the rhabdom in the compound eye of the mosquito

1978 ◽  
Vol 206 (2) ◽  
pp. 151-156 ◽  
Author(s):  
J. D. Brammer ◽  
Peter J. Stein ◽  
Ronald A. Anderson
Keyword(s):  
Dark Adaptation ◽  
Compound Eye ◽  
Effect Of Light

scholarly journals The Eye Muscle of Calliphora Vomitoria L

1973 ◽  
Vol 58 (3) ◽  
pp. 565-583
Author(s):  
JOHN PATTERSON
Keyword(s):  
Dark Adaptation ◽  
Light Adaptation ◽  
Interspike Interval ◽  
Compound Eye ◽  
Optic Lobe ◽  
Visual Images ◽  
Eye Muscle ◽  
Calliphora Erythrocephala ◽  
Spontaneous Movements ◽  
Anatomical Arrangement

1. A muscle attached to the medial edge of the compound eye is described for the blowfly Calliphora vomitoria. 2. Electrophysiological activity in the form of continuous tonically firing potentials can be recorded extracellularly from the muscle. These potentials are generated by the muscle and have the same origin as the ‘clock-spikes’ recorded previously from the optic lobe of Calliphora erythrocephala. 3. The interspike interval of the eye muscle potentials varies inversely with the ambient temperature. 4. Light-adaptation results in a decrease and dark-adaptation an increase in the resting interspike interval of the eye-muscle potentials. 5. Light-adaptation is correlated with increase and dark-adaptation with decrease in the depth of the compound eye as measured at the insertion of the muscle. 6. The pseudopupil produced by illumination of the compound eye from the inside displays spontaneous movements which can be correlated with the anatomical arrangement and spontaneous activity of the eye muscle. 7. The probable function of spontaneous and transient changes in eye-muscle activity is to promote scanning of the visual images produced by the dioptrics of the compound eye.

The Importance of Vision in Agonistic Communication of the Crayfish Orconectes Rusticus. I: an Analysis of Bout Dynamics

Behaviour ◽  
1987 ◽  
Vol 103 (1-3) ◽  
pp. 83-107 ◽  
Author(s):  
Colleen Ann Bruski ◽  
D.W. Dunham
Keyword(s):  
Dark Adaptation ◽  
Compound Eye ◽  
Video Recording ◽  
Visual Sensitivity ◽  
Orconectes Rusticus ◽  
Energy Investment ◽  
Light Levels ◽  
Dim Light ◽  
Time And Energy ◽  
Visual Light

Abstract1. The importance of vision for efficient agonistic communication was investigated in the rusty crayfish, Orconectes rusticus, a species active both day and night. Agonistic bout dynamics were analyzed from isosexual pairs of males and females interacting under moderate (350 lux) and dim (11 lux) light levels, and in complete darkness (using infra-red video recording). Under dim light we determined the effect of visual light and dark adaptation on communication. 2. As light diminished, bouts became less frequent, but longer, and the crayfish invested more time and performed more acts when resolving bouts. Thus, communication efficiency was clearly lower in the dark than under moderate light, for both sexes. Males performed more acts than females overall, and were generally more aggressive than females. 3. The frequency of visually-mediated behaviours (e.g. Lunge, Follow) decreased in the absence oflight, while tactile behaviours (e.g. Antenna Tap, Chela Strike, Push) were performed more frequently. Males especially performed more highly aggressive tactile behaviours in the dark. It was shown that some behaviours previously considered to be visually mediated (e.g. Meral Spread) are also tactually or proprioceptively mediated, and some behaviours assumed to be tactually mediated (e.g. antennal movements) are probably also visually mediated. 4. Under dim light, crayfish with light-adapted eyes resolve bouts more efficiently in terms of time and energy investment than do dark-adapted animals. This is consistent with the effects of pigment migrations during dark adaptation in the crayfish superposition compound eye, which enhance visual sensitivity, but decrease acuity. We suggest that dark adaptation diminishes a crayfishes ability to deal with the subtleties of visual communication, but may well enhance its ability to detect predators.

Study of taurine and tauret content in the compound eye of locust with light and dark adaptation

Amino Acids ◽  
2006 ◽  
Vol 30 (3) ◽  
pp. 273-278
Author(s):  
A. M. Petrosian ◽  
L. A. Poghosyan ◽  
J. E. Haroutounian
Keyword(s):  
Dark Adaptation ◽  
Compound Eye

The Eye Muscle of Calliphora Vomitoria L

1973 ◽  
Vol 58 (3) ◽  
pp. 585-598
Author(s):  
JOHN PATTERSON
Keyword(s):  
Dark Adaptation ◽  
Interspike Interval ◽  
Compound Eye ◽  
Response Threshold ◽  
Interspike Intervals ◽  
Muscle System ◽  
Eye Muscle ◽  
High Stimulus ◽  
Resting Activity ◽  
Effect Of Light

1. Changes in the intensity of the illumination falling on the compound eye produce transient changes in the interspike interval of the tonic potentials generated by the eye muscle of Calliphora vomitoria. These changes are distinct and frequently different in direction from changes in resting activity produced by light and dark adaptation which have been described previously. 2. The effect of ‘light-on’ at high stimulus intensities is to produce a transient increase in the interspike intervals of the eye-muscle potentials. At lower intensities the result is a transient decrease in the interspike intervals. 3. ‘Light-off’ consistently evokes a decrease in the interspike interval, and the magnitude of the decrease is graded with the logarithm of the preceding light intensity. 4. With high-intensity stimuli changes in the interspike intervals occur within 200 msec of a change in illumination and continue to develop for at least 2 sec. The interspike intervals have returned to near to the pre-stimulus values within 30 sec to 2 min of the onset of the stimulus. 5. The behaviour of the eye-muscle system is described for ‘near-threshold’ stimuli and response ‘threshold’ is found to vary with adapting intensity in a way which illustrates a Weber-Fechner relationship.

Depth related variation in the structure and functioning of the compound eye of the Norway lobster Nephrops norvegicus

1990 ◽  
Vol 70 (2) ◽  
pp. 343-355 ◽  
Author(s):  
E. Gaten ◽  
P.M.J. Shelton ◽  
C.J. Chapman ◽  
A.M. Shanks
Keyword(s):  
Deep Water ◽  
Dark Adaptation ◽  
Compound Eye ◽  
Light Exposure ◽  
Retinula Cell ◽  
Nephrops Norvegicus ◽  
Norway Lobster ◽  
Photon Fluence Rate ◽  
Screening Pigment ◽  
Photon Fluence

The mobility and quantity of retinula cell proximal screening pigment, and the liability of the eyes to light-induced damage, were investigated in the Norway lobster, Nephrops norvegicus (L.), obtained from three separate populations from depths of 18, 75, and 135 m.During the morning after capture, the migration of the proximal pigment in response to the onset of illumination below the threshold for damage varied between the three populations. In the eyes of deep water N. norvegicus, the proximal screening pigment was located close to or below the basement membrane when dark-adapted and rose to a position midway up the rhabdoms when light-adapted. In the dark-adapted N. norvegicus from shallow water the proximal pigment was located more distally than in eyes of deep water animals. After the onset of illumination, the pigment migrated distally to completely cover the rhabdoms. The amount of retinula cell proximal screening pigment was found to decrease linearly with depth.When dark-adapted individuals from each depth were exposed to light a positive correlation was obtained between the photon fluence rate (PER) and the proportion of the retina damaged. For a given light exposure the amount of damage was highest in animals from deeper water. The PFR causing 25% damage was approximately 1 log unit higher in animals from 18 m compared to those from 135 m.The amount of damage varied with the delay between capture of the animals and exposure to light. When exposed 2 h after capture significant differences between depths were seen but the results were influenced by the incomplete dark adaptation of some specimens.

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