Spectral sensitivity of vervet monkeys (Cercopithecus aethiops sabaeus) and the issue of catarrhine trichromacy

Several genera of platyrrhine monkeys show significant polymorphism of color vision. By contrast, catarrhine monkeys have usually been assumed to have uniform trichromatic color vision. However, the evidential basis for this assumption is quite limited. To study this issue further, spectral sensitivity functions were obtained from vervet monkeys (Cercopithecus aethiops sabaeus) using the technique of electroretinographic flicker photometry. Results from a chromatic adaptation experiment indicated that each of the twelve subjects had two classes of cone pigment in the 540/640 nm portion of the spectrum. That result strongly suggests that this species has routine trichromatic color vision. Comparison of the spectral sensitivity functions obtained from vervets and from similarly-tested humans further indicates that the cone complements of the two species are very similar. Results from this investigation add further support to the idea that there are fundamental differences in the genetic mechanisms underlying color vision in platyrrhine and catarrhine monkeys.     

Photopigments underlying color vision in ringtail lemurs (Lemur catta) and brown lemurs (Eulemur fulvus)

A recent examination of color vision in the ringtail lemur produced evidence that these prosimians could make color discriminations consistent with a diagnosis of trichromatic color vision. However, it was unclear if this behavior reflected the presence of three classes of cone or whether lemurs might be able to utilize signals from rods in conjunction with those from only two classes of cone. To resolve that issue, spectral sensitivity functions were obtained from ringtail lemurs (Lemur catta) and brown lemurs (Eulemur fulvus) using a noninvasive electrophysiological procedure, electroretinographic flicker photometry. Results from experiments involving chromatic adaptation indicate that these lemurs routinely have only a single class of cone photopigment in the middle to long wavelengths (peak sensitivity of about 545 nm); they also have a short-wavelengthsensitive cone pigment with peak of about 437 nm. The earlier behavioral results are suggested to have resulted from the ability of lemurs to jointly utilize signals from rods and cones. The cone pigment complements of these lemurs differ distinctly from those seen among the anthropoids. © 1993 Wiley-Liss, Inc.     

Electrophysiology of the visual system in the cricket Gryllus firmus (Orthoptera: Gryllidae): Spectral sensitivity of the compound eyes

The electroretinographic spectral sensitivity of the cricket compound eyes shows the presence of two receptor types, a dominant one at 520 nm and another in the near-u.v. (λ_max 355 ± 5 nm) under dark- and intense chromatic adaptation conditions (Fig. 3). The waveform of the electrical responses elicited by short-wavelength stimuli differ from those elicited by long wavelength stimuli (Fig. 1).     

Spectral sensitivity of the green photoreceptor of winged pea aphids

Intracellular recordings are obtained from photoreceptors in the retina of winged (alate) pea aphids Acyrthosiphon pisum (Harris). The responses to monochromatic light, applied in 10‐nm steps over the range 320–650 nm, reveal that all recordings are from green receptors and the spectral sensitivity function of these photoreceptors peaks at 518 nm. A comparison between the spectral sensitivity of the green receptors and extracellular electroretinogram recordings suggests that additional sensitivity to the short‐wavelength light (ultraviolet and/or blue) is also likely to be present in the compound eye of pea aphids. An analysis of the pea aphid genome, comparing its translated nucleotide sequences with the those of the opsin genes of other insect species, supports this electrophysiological finding, although it could not be established whether A. pisum, in addition to the green receptor, has both blue and ultraviolet receptors in the compound eye. The implications of these results for the visual ecology of herbivorous insects are discussed.     

Investigation of inanimate objects by the greater bushbaby (Otolemur garnettii)

Investigatory behavior with novel, inanimate objects by two groups of four juvenile greater bushbabies (Otolemur garnettii) was examined in the laboratory. Substantial investigatory behavior was shown by all subjects. In the first study, subjects showed interest in a wide variety of nonfood stimulus objects. In the second, subjects displayed sustained interest in and investigation of non-food stimulus objects over three sessions. Bushbabies showed preferences for larger, more manipulable objects and variations in total contact over days. Individual differences were observed in the duration and types of contact with objects. These observations contradict earlier reports that prosimians show little interest in inanimate, non-food objects.     

The suprarenal glands of a prosimian primate,the lesser bushbaby (Galago senegalensis)

The gross relationships and light microscopic anatomy of the suprarenal gland of a prosimian primate, Galago senegalensis, is described. The left gland is located medial to the pole of the left kidney in a fascial compartment of its own. The right suprarenal is located medial to the pole of the right kidney in intimate apposition to the liver and inferior vena cava. The capsule of the right gland blends with the capsule of the right lobe of the liver and is also contiguous with the adventitia of the inferior vena cava. The histologic appearance of the gland is similar to that of other primate genera. The zona glomerulosa is poorly developed; the zona fasciculata is composed of cell cords and is relatively well developed and the zona reticularis shows no unusual characteristics. The organization of the lipid content of the various cortical zones show a considerably different pattern than previously reported. The zona glomerulosa contains numerous large lipid droplets. In contrast to the bi-laminar pattern of lipid deposition seen in other primates, the Galago shows three distinct layers of lipid droplets in the zona fasciculata. The zona reticularis has a moderate population of lipid droplets essentially similar to that reported in most other forms. The medulla, except for a sparse number of centrally displaced zona reticularis cells, is completely devoid of lipid deposits. The junction of the zona reticularis and medulla is distinct, although a connective tissue capsule is not present.     

Cycles of mating behaviour, oestrogen and progesterone in the thick-tailed bushbaby (Galago crassicaudatus crassicaudatus) under laboratory conditions

Vaginal smears and blood samples were taken throughout the reproductive cycle of female Galago c. crassicaudatus. Blood plasma was assayed for oestradiol and progesterone, and vaginal smears were initially classified dioestrus or vaginal oestrus. During vaginal oestrus the females were tested daily for sexual receptivity by being placed with a male. Those days on which the male achieved intromission were reclassified as behavioural oestrus. During dioestrus the females were tested weekly with males. Female receptivity increased and then declined across a 6-day period of behavioural oestrus during the 44-day cycle. Fully cornified smears were characteristic of the period of maximal receptivity and oestradiol secretion. The luteal phase lasted 24 days with a plasma progesterone peak midway through dioestrus.     

Spectral sensitivity and flicker fusion frequencies of the compound eye of salmon and wild-type tsetse flies, Glossina morsitans

ABSTRACT. The spectral sensitivity and flicker fusion frequency (FFF) of wild-type and salmon Glossina morsitans morsitans Westwood (Diptera, Glossinidae) were compared electroretinographically (ERG). Spectral sensitivity curves were similar in shape for dark-adapted wild-type and salmon flies, but salmon flies were over 100 times as sensitive as wild-type flies over much of their sensitivity range. Estimation of the spectral absorption curve (from the differences in ERG sensitivities) for the pigment absent from (or present in low concentration in) the salmon eye suggests that the pigment is an ommochrome. FFF at threshold light intensities was similar in wild-type and salmon flies, but at higher light intensity (1.3 °W/cm²) the FFF of salmon flies increased c. 200–300%, due to the capacity of the salmon eye to adapt rapidly to the flicker stimulus. Body weight had little effect upon spectral sensitivity and FFF. Wild-type males were more sensitive to yellow-green light and had higher FFF than did wild-type females. Salmon males and females did not differ in spectral sensitivity, but females had higher FFF (when tested with 520-nm light) than did males. Old wild-type females did not differ from young females in either spectral sensitivity or FFF. However, old salmon females were more sensitive but had lower FFF than young salmon females. Food deprivation reduced spectral sensitivity and FFF in wild-type males but not in salmon males. Irradiation (10.5 krad) reduced spectral sensitivity ( c. 75–375%) and FFF ( c. 30%) in wild-type males. The greatly increased spectral sensitivity and FFF in salmon flies indicate that these flies may behave differently from wild-type flies in the field. Differences in the way spectral sensitivity and flicker discrimination are affected by dark and light adaptation, and by such factors as age and sex, indicate that these measurements are of two independent phenomena.     

New World Monkeys and Color

The visual worlds of most primates are rich with potential color signals, and many representatives of the order have evolved the biological mechanisms that allow them to exploit these sources of information. Unlike the catarrhines, platyrrhines typically have sex-linked polymorphic color vision that provides individuals with any of several distinct types of color vision, including both trichromatic and dichromatic variants. In recent years, this polymorphism has been the target of an expanding range of research efforts. As a result, researchers now reasonably understand the proximate biology underlying the polymorphisms, and a number of ideas have emerged as to their evolution. Progress has also been made in illuminating how color vision capacities may be related to the particular visual tasks that New World monkeys face.     

Enamel microstructure and molar wear in the greater galago,Otolemur crassicaudatus (mammalia,primates)

This study describes the molar enamel microstructure of the greater galago, based on SEM study of four individuals. Galago molar enamel consists primarily of radially oriented Pattern 1 prisms. However, the most superficial enamel is characterized by regions of poorly developed prisms or nonprismatic enamel, and Pattern 3 prisms can be found at depths intermediate and deep to the enamel surface. Orientations of prism long axes relative to wear surfaces differ among functionally distinct regions (cuspal facets, Phase I/II facets, and crushing basins). Consequently, orientations of enamel crystallites relative to these surfaces also differ. Because crystallites are the structural unit involved in enamel abrasion, these differences in orientation may have important effects on molar wear patterns. Crystallite orientations differ most between cuspal facets and Phase I/II facet surfaces. Cuspal facets are characterized by near surface-parallel interprismatic and surface-oblique prismatic crystallites. Previous experimental studies suggest that this arrangement is most resistant to wear when surface-normal (compressive) loads predominate. In contrast, prismatic and interprismatic crystallites intercept Phase I/II facet surfaces obliquely, an arrangement expected to resist abrasion when surface-parallel (shearing) loads predominate. Superficial enamel is preserved at most basin surfaces, indicating that these regions are subject to comparatively little abrasive wear. These results support the hypothesis that galago occlusal enamel is organized so as to resist abrasion of different functional regions, a property that may prove important in maintaining functional efficiency. However, this largely reflects constraints of occlusal topography on a microstructure typical of many mammals and thus does not appear to represent a structural innovation. © 1993 Wiley-Liss, Inc.     

Visual modelling suggests a weak relationship between the evolution of ultraviolet vision and plumage coloration in birds

Birds have sophisticated colour vision mediated by four cone types that cover a wide visual spectrum including ultraviolet (UV) wavelengths. Many birds have modest UV sensitivity provided by violet‐sensitive (VS) cones with sensitivity maxima between 400 and 425 nm. However, some birds have evolved higher UV sensitivity and a larger visual spectrum given by UV‐sensitive (UVS) cones maximally sensitive at 360–370 nm. The reasons for VS–UVS transitions and their relationship to visual ecology remain unclear. It has been hypothesized that the evolution of UVS‐cone vision is linked to plumage colours so that visual sensitivity and feather coloration are ‘matched’. This leads to the specific prediction that UVS‐cone vision enhances the discrimination of plumage colours of UVS birds while such an advantage is absent or less pronounced for VS‐bird coloration. We test this hypothesis using knowledge of the complex distribution of UVS cones among birds combined with mathematical modelling of colour discrimination during different viewing conditions. We find no support for the hypothesis, which, combined with previous studies, suggests only a weak relationship between UVS‐cone vision and plumage colour evolution. Instead, we suggest that UVS‐cone vision generally favours colour discrimination, which creates a nonspecific selection pressure for the evolution of UVS cones.     

中华通草蛉复眼光感受性

运用视网膜电位（Electroretinogram,ERG）技术,对中华通草蛉Chrysopa sinica Tjedar成虫复眼在暗适应过程中对单色光和白光刺激的光感受变化进行了测定。结果表明：（1）在340～605 nm光谱范围内该草蛉的光反应表现3个峰,其中最高峰位于562 nm,次峰在524 nm,第3峰在460 nm;（2）一定光强度（LogI=4.5～0）范围内,其复眼ERG值随光强度的增强而增大,呈近线性增长式样;（3）暗适应时间影响其复眼的ERG值大小,在暗适应100 min时其ERG值达到稳定;（4）中华通草蛉复眼ERG的波形由4个部分组成：开光反应、正相电位、持续负电位和闭光反应。     

A comparative study of spectral sensitivity curves in three diurnal and eight nocturnal species of Japanese fireflies

The spectral properties of the eyes of 3 species of diurnal and 8 species of nocturnal Japanese fireflies, in many cases males and females, were determined by an electroretinographic method. With the exception of Hotaria parvula males, which had a λ_max of 580 nm, almost all species studied possessed a maximum around 500–540 nm. The eyes of diurnal and nocturnal species did not differ significantly in their sensitivity maxima. As in North American species of fireflies (Lall, 1981a,b) congruency existed between visual sensitivity peaks and light emission maxima in Luciola cruciata, L. lateralis and Hotaria parvula. In agreement with Seliger et al. (1982a,b) we conclude that an adaptation of the visual sensitivity to the light produced need not have occurred and that evolutionary adaptation of light emission to an existing ancestral green-sensitivity of the eye is the more likely course of events.     

Spectral sensitivity of photoreceptors in the compound eye of stingless tropical bees

The spectral sensitivity of photoreceptors of the tropical bees Melipona quadrifasciata, M. marginata, and Trigona spinipes were measured on-line with a rapid constant response amplitude method. The results indicate that although these bees forage in different habitats they have the same set of photoreceptors with sensitivity maxima in ultra-violet, blue and green.     

SPECTRAL SENSITIVITY IN TWO SPECIES OF PINNIPEDS (PHOCA VITULINA AND OTARIA FLAVESCENS)

Spectral sensitivity was measured in air in the light adapted state in two harbor seals and a South American sea lion using a behavioral training technique. Increment thresholds were determined in a spectral range from 390 nm to 670 nm in a simultaneous two‐choice discrimination task. The spectral sensitivity curves show two maxima in sensitivity, one main peak with a maximum around 500 nm in the harbor seal and around 550 nm in the South American sea lion, and a second, smaller peak with a maximum in the range of 410 nm in both species. The broad shape and the position of the maximum of the spectral sensitivity curve of the harbor seals suggests that even under photopic conditions both rods and cones are contributing to the measurements since harbor seals possess only one cone type. The maximum sensitivity in the green part of the spectrum may indicate an adaptation to a specific underwater environment.     

Visual spectral sensitivity of hatchling loggerhead (Caretta caretta L.) and leatherback (Dermochelys coriacea L.) sea turtles,as determined by single-flash electroretinography

Electroretinographic recordings were made from hatchling loggerhead and leatherback sea turtle eyecup preparations to generate dark-adapted spectral sensitivity curves. Both species were maximally sensitive to wavelengths between 500 and 540 nm, with a secondary peak near 380 nm. The spectral sensitivity curve for leatherbacks was attenuated at the long wavelength end of the spectrum relative to that of the loggerheads. This difference may reflect adaptations to lighting available at the relatively shallow (loggerhead) versus deeper (leatherback) sites where each species forages. The broad spectrum of wavelengths detected by both species (near UV to yellow–orange) indicates that vision is likely mediated by more than one photopigment, potentially rendering these turtles capable of color vision.