Spectral sensitivity, visual pigments and screening pigments in two life history stages of the ontogenetic migrator Gnathophausia ingens

2009 ◽  
Vol 89 (1) ◽  
pp. 119-129 ◽  
Author(s):  
Tamara M. Frank ◽  
Megan Porter ◽  
Thomas W. Cronin
Keyword(s):  
Life History ◽  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Chromatic Adaptation ◽  
Age Classes ◽  
Long Wavelength ◽  
Life History Stages ◽  
Near Ultraviolet ◽  
Maximal Sensitivity ◽  
Absorbance Spectra

Spectral sensitivity, visual pigment absorbance spectra and visual pigment opsin sequences were examined in younger shallow-living and older deep-living instars of the ontogenetically migrating lophogastrid Gnathophausia ingens. Spectral sensitivity measurements from dark adapted eyes and microspectrophotometric measurements of the rhabdom indicate maximal sensitivity for long wavelength (495–502 nm) light in both life history stages, but the younger instars are significantly more sensitive to near-ultraviolet light than the adults. Both life history stages express the same two opsins, indicating that there is no ontogenetic change in visual pigment complement between life history stages. Chromatic adaptation shifted the spectral sensitivity maximum to significantly longer wavelengths in both age-classes, but a distinct secondary short wavelength peak is visible only in the younger instars. These shifts appear to be due to the presence of migrating screening pigments, which are probably vestigial in the deep-living adults. Anomalies in the response waveforms under chromatic adaptation also apparently result from filtering by screening pigments, but via an unknown mechanism.

scholarly journals Electroretinogram Characteristics and the Spectral Mechanisms of the Median Ocellus and the Lateral Eye in Limulus polyphemus

1967 ◽  
Vol 50 (9) ◽  
pp. 2267-2287 ◽  
Author(s):  
Robert M. Chapman ◽  
Abner B. Lall
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Light Adaptation ◽  
Compound Eye ◽  
State Level ◽  
Chromatic Adaptation ◽  
Absorption Bands ◽  
Energy Functions ◽  
Lateral Eye ◽  
Median Ocellus

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.

The Sensitivity of Housefly Photoreceptors in the Mid-Ultraviolet and the Limits of the Visible Spectrum

1968 ◽  
Vol 49 (3) ◽  
pp. 669-677
Author(s):  
TIMOTHY H. GOLDSMITH ◽  
HECTOR R. FERNANDEZ
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Visible Spectrum ◽  
Wild Type ◽  
Long Wavelength ◽  
Wavelength Limit ◽  
Sharp Band ◽  
In The Wild ◽  
Filtering Effect ◽  
Spectral Sensitivity Curve

1. The spectral sensitivity of the photoreceptors of a white-eye mutant of the housefly Musca domestica has been measured to 250 nm. in the mid-ultraviolet. Maximum sensitivity is at 340-350 nm., as in the wild-type eye, and decreases at shorter wavelengths with a distinct shoulder at 280 nm. 2. Microspectrophotometric measurements of individual corneal facets show little absorption at wavelengths longer than 300 nm. but a sharp band (peak density about 0.4) at 277 nm. Adjustment of the spectral sensitivity curve for the filtering effect of the cornea makes the 280 nm. shoulder more prominent, suggesting the presence of energy transfer from the protein component of the visual pigment to the chromophore. 3. The short-wavelength limit of the housefly's visible spectrum is determined by the availability of ultraviolet light and is about 300 nm. in nature. The long-wavelength limit is set by the falling absorption of the visual pigment in the red.

Mapping absorbance spectra, cone fractions, and neuronal mechanisms to photopic spectral sensitivity in the zebrafish

2002 ◽  
Vol 19 (3) ◽  
pp. 365-372 ◽  
Author(s):  
DAVID A. CAMERON
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Second Order ◽  
Visual Sensitivity ◽  
Cone Photoreceptors ◽  
Chromatic Contrast ◽  
Good Correspondence ◽  
First Order ◽  
Neuronal Mechanisms ◽  
Absorbance Spectra

The four spectral cone types in the zebrafish retina each contribute to photopic visual sensitivity as measured by the b-wave of the electroretinogram (ERG). The goal of the current study was to evaluate a model of photopic b-wave spectral sensitivity in the zebrafish that mapped first-order cellular and biophysical aspects of cone photoreceptors (visual pigment absorbance spectra and cone fractions) onto a second-order physiological aspect of cone-derived neural activity in the retina. Good correspondence between the model and photopic ERG data was attained using new visual pigment absorbance data for zebrafish cones (λmax of the L, M, and S cones were 564, 473, and 407 nm, respectively), visual pigment templates, and linearly gained cone fractions. The model inferred four distinct cone processing channels that contribute to the photopic b-wave, two of which are antagonistic combinations of cone-derived signals (L-M and M-S), and two of which are noncombinatorial signals from S and U cones. The nature of the gains and the processing channels suggested general rules of cone-specific inputs to second-order neurons. The model further suggested that the zebrafish retina utilizes neuronal mechanisms for enhancing sensitivity to luminance contrast at short wavelengths and chromatic contrast at middle and long wavelengths. The results indicated that first-order cellular and biophysical aspects of cone photoreceptors can successfully explain physiological aspects of cone-derived neuronal activity in the zebrafish retina.

Variation in opsin transcript expression explains intraretinal differences in spectral sensitivity of the northern anchovy

2018 ◽  
Vol 35 ◽  
Author(s):  
ILARIA SAVELLI ◽  
IÑIGO NOVALES FLAMARIQUE
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Chromatic Adaptation ◽  
Molecular Component ◽  
Retinal Photoreceptors ◽  
Northern Anchovy ◽  
Vitamin A Derivative ◽  
Molecular Components ◽  
Human And Mouse ◽  
Dorsal Retina

AbstractVertebrate retinal photoreceptors house visual pigments that absorb light to begin the process of vision. The light absorbed by a visual pigment depends on its two molecular components: protein (opsin) and chromophore (a vitamin A derivative). Although an increasing number of studies show intraretinal variability in visual pigment content, it is only for two mammals (human and mouse) and two birds (chicken and pigeon) that such variability has been demonstrated to underlie differences in spectral sensitivity of the animal. Here, we show that the spectral sensitivity of the northern anchovy varies with retinal quadrant and that this variability can be explained by differences in the expression of opsin transcripts. Retinal (vitamin A1) was the only chromophore detected in the retina, ruling out this molecular component as a source of variation in spectral sensitivity. Chromatic adaptation experiments further showed that the dorsal retina had the capacity to mediate color vision. Together with published results for the ventral retina, this study is the first to demonstrate that intraretinal opsin variability in a fish drives corresponding variation in the animal’s spectral sensitivity.

Methodological recommendations for ungulate mortality analyses in paleoanthropology

2010 ◽  
Vol 74 (3) ◽  
pp. 388-394 ◽  
Author(s):  
Henry T. Bunn ◽  
Travis Rayne Pickering
Keyword(s):  
Life History ◽  
Tooth Wear ◽  
Age Classes ◽  
Size Classes ◽  
Life History Stages ◽  
Dental Eruption ◽  
Animal Remains ◽  
Occlusal Wear ◽  
Old Adult ◽  
Ungulate Mortality

AbstractAge profiling of fossil faunal samples relies on the correlation of animal tooth-wear patterns with life history stages, but the criteria used to infer these stages are not necessarily valid. Here we redefine some commonly used prey age classes, such as “juvenile,” “prime-age adult,” and “old adult,” based on the variable characteristics of tooth wear that we have observed in different ungulate size classes, and argue that prey vulnerability to predation is not so clearly predicted by the simplified age classes in widespread use by zooarchaeologists. We recommend instead classifying the youngest animal remains as either young juvenile or subadult juvenile, and adult remains as early prime, late prime or old, and provide specific criteria of dental eruption and occlusal wear for making these determinations. We argue this refined age profiling system, when used in combination with other types of zooarchaeological and taphonomic data, can provide accurate inferences of faunal accumulation processes.

scholarly journals The Spectral Sensitivities of Single Cells in the Median Ocellus of Limulus

1969 ◽  
Vol 54 (5) ◽  
pp. 636-649 ◽  
Author(s):  
John Nolte ◽  
Joel E. Brown
Keyword(s):  
Visible Light ◽  
Spectral Sensitivity ◽  
Uv Light ◽  
Single Cells ◽  
Chromatic Adaptation ◽  
Sensitivity Curve ◽  
Receptor Cells ◽  
Intracellular Microelectrodes ◽  
Median Ocellus ◽  
Spectral Sensitivity Curve

The spectral sensitivities of single Limulus median ocellus photoreceptors have been determined from records of receptor potentials obtained using intracellular microelectrodes. One class of receptors, called UV cells (ultraviolet cells), depolarizes to near-UV light and is maximally sensitive at 360 nm; a Dartnall template fits the spectral sensitivity curve. A second class of receptors, called visible cells, depolarizes to visible light; the spectral sensitivity curve is fit by a Dartnall template with λmax at 530 nm. Dark-adapted UV cells are about 2 log units more sensitive than dark-adapted visible cells. UV cells respond with a small hyperpolarization to visible light and the spectral sensitivity curve for this hyperpolarization peaks at 525–550 nm. Visible cells respond with a small hyperpolarization to UV light, and the spectral sensitivity curve for this response peaks at 350–375 nm. Rarely, a double-peaked (360 and 530 nm) spectral sensitivity curve is obtained; two photopigments are involved, as revealed by chromatic adaptation experiments. Thus there may be a small third class of receptor cells containing two photopigments.

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