Spectral absorption by screening pigment granules in the compound eyes of a moth and a wasp

1970 ◽  
Vol 67 (3) ◽  
pp. 238-242 ◽  
Author(s):  
G. H�glund ◽  
H. Langer ◽  
G. Struwe ◽  
B. Thorell
Keyword(s):  
Compound Eyes ◽  
Spectral Absorption ◽  
Pigment Granules ◽  
Screening Pigment

The divided eye of the isopod Glyptonotus antarcticus : effects of unilateral dark adaptation and temperature elevation

1982 ◽  
Vol 215 (1201) ◽  
pp. 433-450 ◽  
Keyword(s):  
Membrane Damage ◽  
Pigment Granule ◽  
Bright Light ◽  
Interstitial Cells ◽  
The Other ◽  
Compound Eyes ◽  
Temperature Elevation ◽  
Dark Light ◽  
Pigment Granules ◽  
Screening Pigment

The literature on the structure and function of isopod compound eyes is briefly reviewed. Unlike other isopods studied, Glyptonotus antarcticus possesses physi­cally separated large dorsal compound eyes and small ventral compound eyes. G. antarcticus turns upside down when it swims, and it seems that this is when the ventrally located eyes become useful. Structurally, the two types of eye are very similar : both consist of individual ommatidia, which in an adult specimen can be 80–100 μm wide and 300 μm long. Each ommatidium contains a bipartite crystalline cone and a long rhabdom, approximately 100 μm long, which is characteristically star-shaped when sectioned transversely. Sometimes five and sometimes six retinula cells contribute to the formation of the centrally located, fused and unbanded rhabdom. Dark-light adaptational changes were difficult to demonstrate and did not occur until one eye was kept covered and shielded from light for one week, while the other one remained uncovered. In eye pairs of five animals treated in this way, it was obvious that prolonged darkness leads to an outward migration of retinula screening pigment granules, to the formation of multivesicular bodies in the retinula cells, and to an increase in size and abundance of spherical organelles in the interstitial cells. Exposure to light, on the other hand, results in an inward (towards the rhabdom) migration of retinula cell screening pigment granules, the formation of multilamellar bodies through pinocytotic processes at the rhabdom edge, and a swelling of interstitial cells. Temperature elevation alone mimics the effects of bright light with regard to pigment granule migration. It is suggested that, when pigment granules absorb radiation during exposure to light under normal environ­mental temperature conditions, they may heat up their immediate surroundings sufficiently to contribute to membrane damage.

Diurnal changes in retinula cell sensitivities and receptive fields (two-dimensional angular sensitivity functions) in the apposition eyes of Ligia exotica (Crustacea, Isopoda)

2001 ◽  
Vol 204 (2) ◽  
pp. 239-248 ◽  
Author(s):  
T. Hariyama ◽  
V.B. Meyer-Rochow ◽  
T. Kawauchi ◽  
Y. Takaku ◽  
Y. Tsukahara
Keyword(s):  
Receptive Fields ◽  
Resolving Power ◽  
Pigment Cells ◽  
Diurnal Changes ◽  
Two Dimensional ◽  
Angular Sensitivity ◽  
Pigment Granules ◽  
Screening Pigment ◽  
The Difference ◽  
Night And Day

The structural organization of the retinula cells in the eye of Ligia exotica changes diurnally. At night, the microvilli elongate, losing the regular and parallel alignment characteristic of the day condition. Crystalline cones and distal rhabdom tips are not pushed into each other during the day, but at night the rhabdoms protrude into the crystalline cones by up to 5 microm. Screening pigment granules in the retinula cells disperse during the night, but migrate radially towards the vicinity of the rhabdom during the day. No such displacements of the pigment granules of either distal or proximal screening pigment cells were observed. The sensitivity of the eye, monitored by electroretinogram (ERG) recordings, changes diurnally: values at midnight are, on average, 10 times those occurring during the day. However, intracellular recordings from single retinula cells (50 during the day and 50 at night) indicate that the difference between night and day sensitivities is only 2.5-fold. Two-dimensional angular sensitivity curves, indicative of a single unit's spatial sensitivity, had considerably less regular outlines at night than during the day. If based on the 50 % sensitivity level, day and night eyes possessed receptive fields of almost identical width (approximately 2 degrees), but if sensitivities below the 50 % limit were included, then receptive fields at night were significantly more extensive. We suggest that the morphological adaptations and diurnal changes in chromophore content seen in the apposition eye of L. exotica allow this animal to improve its photon capture at night while preserving at least some of the spatial resolving power characteristic of the light-adapted state. This would explain why this animal is capable of performing complex escape behaviours in the presence of predators both in bright and in very dim light.

EFFECT OF DIFFERENT LIGHTING CONDITIONS ON FEEDING ACTIVITY AND EYE ADAPTATION OF POST LARVAE PENAEUS VANNAMEI

2015 ◽  
Vol 77 (33) ◽  
Author(s):  
Noorsyarinah Sanudin ◽  
Audrey Daning Tuzan ◽  
Gunzo Kawamura ◽  
Annita Seok Kian Yong
Keyword(s):  
Feeding Activity ◽  
Light Condition ◽  
Larval Feeding ◽  
Penaeus Vannamei ◽  
Dark Condition ◽  
Clear Zone ◽  
Lighting Conditions ◽  
Pigment Granules ◽  
Screening Pigment ◽  
Dark Conditions

This study was conducted to investigate the effect of light and dark conditions on feeding activity and eye adaptations of post larvae (PL5, PL10, PL20 and PL30) Penaeus vannamei fed with frozen Artemia. Shrimp PL were placed individually in beakers and after acclimatization under the light or dark condition, PL were left to ingest known number of Artemia for 30 minutes. Thereafter, each PL was subsequently anesthetized by putting an ice cube into the beakers followed by adding few drops of paraformaldehyde. The results showed that the PL5 ingested significantly more frozen Artemia under light condition compared to dark condition (P<0.05). The eye structures of PL5 comprises of crystalline cone, rhabdom and fasciculated zone. However, it was incomplete due to the lack of clear zone and no migration of the screening pigment granules was observed under light and dark conditions. On the contrary, the number of frozen Artemia ingested by the latter stages PL10, PL20 and PL30 showed no significant differences (P>0.05) under both light conditions and these PL have complete eye structures with define clear zone. The width of clear zone was found to increase proportionally with the growth of the PL. Besides that, the screening pigment granules were able to migrate under light and dark conditions. The ability of the PL10, PL20 and PL30 to ingest almost similar numbers of Artemia under light and dark conditions suggests that different lighting conditions did not affect the feeding activity of the PL and other sensory organs may play roles in detecting food, while PL5 need light to improve their feeding activity. Based on these results, we suggest that in aquaculture practice, during the rearing of early stage of PL (<PL5), a brighter environment or light should be provided to enhance larval feeding activities. Whereas, later stages of PL (>PL10) can be cultured under any light condition.

scholarly journals The pigment granules in the compound eyes of Drosophila

Heredity ◽  
1961 ◽  
Vol 16 (1) ◽  
pp. 25-38 ◽  
Author(s):  
D J Nolte
Keyword(s):  
Compound Eyes ◽  
Pigment Granules

scholarly journals Changes in the structure and pigmentation of the eyes of honeybee (Apis mellifera L.) queens with the "limão" mutation

2000 ◽  
Vol 23 (1) ◽  
pp. 93-96 ◽  
Author(s):  
José Chaud-Netto ◽  
Carminda da Cruz-Landim
Keyword(s):  
Apis Mellifera ◽  
Morphological Changes ◽  
Compound Eyes ◽  
Ultrastructural Organization ◽  
Multivesicular Bodies ◽  
Electron Dense Material ◽  
Eye Color ◽  
Receptor Cells ◽  
Pigment Granules ◽  
Retinular Cells

This study describes the ultrastructural differences between the compound eyes of ch li/ch li and Ch/ch li honeybee queens. Heterozygous "limão" bees had an almost normal ultrastructural organization of the ommatidia, but there were some alterations, including small vacuoles in the crystalline cones and a loss of pigment by primary pigmentary cells. In homozygous bees many ommatidia had very deformed crystalline cones and there were some bipartite rhabdoma. There was a reduction in the amount of pigment in the primary and secondary pigmentary cells and receptor cells (retinulae) of mutant eyes. However, the eyes of both heterozygous and homozygous queens had the same type of pigment granules. Certain membrane-limited structures containing pigment granules and electron-dense material appeared to be of lysosomal nature. Since these structures occurred in the retinular cells of mutant eyes, they were considered to be multivesicular bodies responsible for the reduction in rhabdom volume in the presence of light, as a type of adaptation to brightness. The reduction of pigment in the pigmentary and retinular cells and the morphological changes seen in the rhabdom of the ommatidia may originate visual deficiencies, which could explain the behavioral modifications reported for Apis mellifera queens with mutant eye color.

scholarly journals Screening pigment of the camera eyes of stalkeyed mollusks (Pulmonata, Stylommatophora) with different light preferences

2017 ◽  
Vol 27 (3) ◽  
pp. 133-140
Author(s):  
I. P. Shepeleva
Keyword(s):  
Electron Density ◽  
Morphological Properties ◽  
Light Conditions ◽  
Pigment Granules ◽  
Screening Pigment ◽  
Gastropod Mollusks

Morphological properties of the granules of the screening pigment in the retinae of camera eyes of gastropod mollusks with different light preferences were studied. It was demonstrated that the pigment granules of mollusks can differ by color and size but do not differ by structure, electron density and form. Light conditions of mollusks’ habitats can influence on the amount of the screening pigment, which in its turn does not affect resolving ability of the eyes.

Evidence for a Pathway of Distal Screening Pigment Granules across the Basement Membrane of the Crayfish Photoreceptor

1992 ◽  
Vol 47 (5-6) ◽  
pp. 453-464
Author(s):  
Ulrich Schraermeyer
Keyword(s):  
Basement Membrane ◽  
Light Adaptation ◽  
Procambarus Clarkii ◽  
Pigment Cell ◽  
Dense Material ◽  
Pigment Cells ◽  
Electron Dense Material ◽  
Orconectes Limosus ◽  
Pigment Granules ◽  
Screening Pigment

The distal pigment cells of Orconectes limosus contain two layers of large electron lucent vacuoles that are separated by layers of small right-angled platelets adjacent to the crystalline cones. The crystalline cones of the dioptric apparatus of this species have evaginations into the distal pigment cell cytoplasm. In photoreceptors of Orconectes limosus and Procambarus clarkii a dark pigment accumulation site was detected just distal to the basement membrane at the edges of each retina. These pigment accumulations occurred independent of the state of light adaptation. Ultrastructurally the pigment granules at this accumulation site resemble distal screening pigment granules according to their size (up to 1.2 μm in diameter) and fibrous structure. Distal screening pigment granules were also found in tube-like cell processes or extracellularly within and proximal to the retinal basement membrane, indicating pigment transport to and across the basement membrane. Proximal to the basement membrane screening pigment granules were also observed disintegrated to a gravel-like electron dense material in widely branched cells. Evidence was found that an electron dense material, probably resulting from disintegrating screening pigment granules, was incorporated in the integument of the eyestalk. Four hours after injection of gold particles into the eye stalk distal to the retina they were detected inside and proximal to the retinal basement membrane.

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