Inheritance of the harlequin color in Great Dane dogs

The harlequin color pattern of Great Dane dogs differs from merle in that the background is white instead of blue. Harlequin by harlequin matings produced 60 black, 77 harlequin, 42 merle, and 35 homozygous merle pups. Harlequin by black matings produced 44 black, 26 harlequin, 25 merle, and one white (homozygous merle?) pups. All harlequins produced some merles. These data best fit the hypothesis that harlequin is a modification of merle (Mm) caused by an autosomal dominant mutation that is lethal to homozygotes, and to about half of heterozygotes when combined with the MM genotype. The symbol H is proposed for this mutation.     

Genome-wide linkage scan localizes the harlequin locus in the Great Dane to chromosome 9

Harlequin is a coat pattern of the Great Dane characterized by ragged patches of full color on a white background. Harlequin patterning is a bigenic trait, resulting from the interaction of the merle allele of SILV, and a dominant modifier locus, H. Breeding data suggest that H is embryonic recessive lethal and that all harlequins are Hh. To identify linkage with the harlequin phenotype, 46 Great Danes from 5 pedigrees were genotyped for 280 microsatellite markers in a whole genome screen. One marker on the telomeric end of chromosome 9 was suggestive of linkage. Fine mapping of this region using additional microsatellite markers and 10 Great Danes from a sixth pedigree resulted in significant LOD scores for 2 markers. Reported herein is linkage mapping of the H locus to a 3.27 Mb region of chromosome 9 containing approximately 20 genes.     

Conspicuousness,color resemblance,and toxicity in geographically diverging mimicry: The pan‐Amazonian frog Allobates femoralis

Predation risk is allegedly reduced in Batesian and Müllerian mimics, because their coloration resembles the conspicuous coloration of unpalatable prey. The efficacy of mimicry is thought to be affected by variation in the unpalatability of prey, the conspicuousness of the signals, and the visual system of predators that see them. Many frog species exhibit small colorful patches contrasting against an otherwise dark body. By measuring toxicity and color reflectance in a geographically variable frog species and the syntopic toxic species, we tested whether unpalatability was correlated with between‐species color resemblance and whether resemblance was highest for the most conspicuous components of coloration pattern. Heterospecific resemblance in colorful patches was highest between species at the same locality, but unrelated to concomitant variation in toxicity. Surprisingly, resemblance was lower for the conspicuous femoral patches compared to the inconspicuous dorsum. By building visual models, we further tested whether resemblance was affected by the visual system of model predators. As predicted, mimic‐model resemblance was higher under the visual system of simulated predators compared to no visual system at all. Our results indicate that femoral patches are aposematic signals and support a role of mimicry in driving phenotypic divergence or mimetic radiation between localities.     

Ultrastructural variation tune wing coloration of a moth Asota caricae Fabricius, 1775

Butterflies and moths develop highly ordered coloration in their wing for signal transmission. We have investigated the ultrastructural arrangement of wing coloration of a moth Asota caricae, applying light, optical polarized, and scanning electron microscopy, and spectrophotometry. The forewing of the moth is brown in color with a white spot at the center. The hindwing is golden yellow in color with many black patches in it. The ventral part of the forewing and dorsal hindwing share the similar color pattern. The ventral part of the hindwing has dull coloration in comparison to the dorsal one although the pattern remains same. The spectrometry analysis reveals various patterns of absorbance and reflectance spectra for various colors. The peak observed for various colors remain same although the intensity of peak changes. Bright colors possess highly ordered structures whereas irregular structures are found in dull colored scales. The color variation observed due to dorsal and ventral part of the wing is due to the minute difference observed in terms of ultrastructural arrangement revealed by scanning electron microscope. The color pattern of A. caricae is due to variation of microstructures present within the scale.     

SEXUAL SELECTION AND THE EVOLUTION OF COMPLEX COLOR PATTERNS IN DRAGON LIZARDS

Many species have elaborate and complex coloration and patterning, which often differ between the sexes. Sexual selection may increase the size or intensity of color patches (elaboration) in one sex or drive the evolution of novel signal elements (innovation). The latter potentially increases color pattern complexity. Color pattern complexity may also be influenced by ecological factors related to predation and environment; however, very few studies have investigated the effects of both sexual and natural selection on color pattern complexity across species. We used a phylogenetic comparative approach to examine these effects in 85 species and subspecies of Australian dragon lizards (family Agamidae). We quantified color pattern complexity by adapting the Shannon–Wiener diversity index. There were clear sex differences in color pattern complexity, which were positively correlated with both sexual dichromatism and sexual size dimorphism, consistent with the idea that sexual selection plays a significant role in the evolution of color pattern complexity. By contrast, we found little evidence of a link between environmental factors and color pattern complexity on body regions exposed to predators. Our results suggest that sexual selection rather than natural selection has led to increased color pattern complexity in males.     

Agnetina den, a new species of perlid stonefly (Plecoptera: Perlidae) from Vietnam

A new species of perlid stonefly, Agnetina den, is described from Vietnam. Male adults of this species can be easily distinguished by their black body color pattern, submedian patches of sensilla basiconica on hemitergites 7–8, and clusters of long dense fine setae on the inner sides the abdominal tergites. Illustrations of habitat and diagnostic characters are presented.     

Group Effects and Background Color Patterns Affect the Exploratory Behavior of Tree Sparrows

Exploratory behavior serves the function of acquiring information when facing environmental uncertainty, thus plays an important role for animals living on patchy or ephemeral resources. Our study tested the hypothesis that exploratory behavior is affected by ecological factors associated with the risk of predation. We conducted experiments to examine exploration behavior of wild‐caught Eurasian tree sparrows (Passer montanus) under the influences of background color patterns (white or camouflaged) and group sizes (single vs. five sparrows). We further conducted two‐pattern choice experiments and offered sparrows backgrounds combining those two color patterns. In comparisons with single sparrows, flocking sparrows had shorter landing latencies, started exploring sand patches earlier, spent less total time on the ground before pecking at the first patch and nearly successfully located and pecked all patches. In contrast, sparrows responded nearly indifferently to the two single‐pattern backgrounds; yet when given a choice, sparrows still favored the camouflaged portion in the two‐pattern backgrounds and first landed more frequently there. Twice as many patches were left untouched on the two‐pattern backgrounds, mostly by single sparrows, than on both types of single‐pattern backgrounds. In tests of flocks, sparrows that first landed on the ground to initiate exploration had a higher chance to also first explore a sand patch than random expectation on single‐pattern backgrounds, but not necessarily on two‐pattern backgrounds. Our results demonstrate context‐specific effects of social exploration, suggest possible influence of individual variation and offer evidence for advantages of group living in situations where explorers have to cope with environmental uncertainty.     

Variability of the hard dorsal idiosomal tegument pattern and other phenotypic characters as a manifestation of microevolution in Dermacentor marginatus (Acari: Ixodidae)

The pattern of male conscutum and female scutum in Dermacentor marginatus has been examined in 6 points of the East-European and Asian parts of its range (Fig. 1). A high rate of modification variability of the pattern has been recovered in each geographical sample. It is shown that populations differ reliably from each other by the length of the dark patches on the marginal flank of the conscutum (nkappabeta, npkappabeta, 3kappabeta); some samples also differ by the number of these patches, complexes of other patches of the scutum and conscutum, and as well (visually) by the color density of light fields and contrast between them and the dark background on the conscutum and scutum (Table 1, 2). Besides, the samples differ reliably at each stage by the complexes of morphometric characters (Table 3, 4). The sample from the Peter the First Ridge is most deviate from others by the color contrast and complex of patches both in males and females. However, by the patches of marginal flank and morphometric characters of both sexes and perimaginal stages this sample differ less from others. The sample from the Stavropol plateau having most variable pattern (Fig. 3, 1-9, 4, 1-3) is characterized by the greater number of statistically reliable differences by the patches (nkappabeta, npkappabeta, 3kappabeta) and morphometric characters of all stages of the ontogenesis from all other samples. Other geographical samples have intermedial position in regard to degree of differences from each other. The samples examined are considered as morphotypes; degree of differences between morphotypes is unequal. The phenotypic differences have mosaic dispersion among ontogenetic stages and do not show a coherent direction in comparing the morphotypes. Differential characters of the morphotypes and related tick species belong to different structures or their different parameters. Possible ways of morphotype's origin and geochronological characteristics of morphotypes are discussed.     

Reproductive Signals of Female Lizards: Pattern of Trait Expression and Male Response

Relative to the volume of studies concerning the function and evolution of male‐biased sexually dimorphic traits, instances of female‐biased sexual dimorphisms remain largely unstudied, especially in species with conventional sex roles. I investigated the signal function of a female‐specific ornamental trait using the striped plateau lizard (Sceloporus virgatus, Phrynosomatidae) as a model system. During the reproductive season, female S. virgatus develop orange color on their throats that is absent in conspecific males. I established the relationship between color expression and female reproductive state, and determined male response to female color. I show that dynamic changes occurring within the color patch can potentially identify each stage of the female reproductive cycle, largely because of a lag in patch growth relative to color intensification. Sexual receptivity is associated with intense patches rapidly growing in size; ovulation occurs near peak color expression; and the unreceptive period is associated with large patches fading in intensity. Because females express orange color during both the receptive and unreceptive periods, the pattern of color expression is consistent with the courtship‐stimulation and courtship‐rejection hypotheses of signal function. Males may preferentially associate with females that have more highly developed color patches during the courtship season, and/or ignore such females when they are unreceptive. An examination of male behavior towards unfamiliar females indicates that female color has a role in courtship stimulation but has little, if any, role in courtship rejection. During the pre‐mating season, males maintained significantly closer affiliation with, and tended to perform more social behavior towards females with more intense color. During the post‐mating season, female color had no apparent effect on male behavior. The evolution and current function of female ornaments may vary among taxonomically‐related species as a result of differences in ecology, social system, and life‐history.     

Heritable syndrome of skeletal defects in a family of Australian shepherd dogs

A syndrome of multiple defects including cleft palate, polydactyly, and often syndactyly, shortened tibia-fibula, brachygnathism and scoliosis lethal to males is described in a family of Australian shepherd dogs. Female pups lack the cleft palate and survive, but may exhibit the other defects to a lesser degree than do males. Litter data suggest that the trait is inherited as an X-linked lethal gene, but the possibility of a sex-influenced autosomal allele cannot be ruled out. The syndrome may have arisen in conjunction with instability of the merle locus.     

The evolution of feather coloration and song in Old World orioles (genus Oriolus)

What is the tempo and mode of evolution – how fast and in what pattern do traits evolve – is a major question of evolutionary biology. Here we studied patterns of evolutionary change in visual and acoustic signals in Old World orioles. Since producing multiple signals may be costly, we also tested whether there was an evolutionary trade‐off between the elaboration of those two types of signals. We studied 30 Oriolus taxa using comparative methods and a recent molecular phylogeny. Morphology and plumage hue evolved comparatively slowly, whereas song evolved rapidly. Among individual feather patches, the evolutionary rate of color was slowest in primaries, which are critical for flapping flight, and fastest in patches exposed to observers (mantle and breast). Thus, primaries seem to be under functional constraint while the evolution of visually exposed patches is perhaps shaped by sexual selection. Song evolution was comparatively fast, but also attracted to a single optimum. This may be due to selection for signal efficacy, because all orioles inhabit similar forested habitats. Only color diversity was best fit by a speciational model: the biggest changes in coloration were concentrated at speciation events, thus perhaps linked to the evolution of species recognition. Our analysis did not reveal any evolutionary trade‐off between acoustic and visual signals, suggesting that the elaboration of visual and acoustic signals in the Old World orioles evolved independently. Our study shows that patterns of evolutionary change may be surprisingly complex even within a single clade of birds and thus further studies are needed to identify general patterns of signal macroevolution.     

Behavior, color change and time for sexual inversion in the protogynous grouper (Epinephelus adscensionis)

Hermaphroditism, associated with territoriality and dominance behavior, is common in the marine environment. While male sex-specific coloration patterns have been documented in groupers, particularly during the spawning season, few data regarding social structure and the context for these color displays are available. In the present study, we define the social structure and male typical behavior of rock hind (Epinephelus adscensionis) in the wild. In addition, we detail the captive conditions and time period necessary to induce the onset of the sex-specific coloration and sexual change. At six oil production platform locations in the Gulf of Mexico, rock hind social group size and typical male rock hind social behavior were documented. We observed a rapid temporary color display in rock hind that could be turned on and off within three seconds and was used for confronting territory intruders and displays of aggression towards females. The male-specific "tuxedo" pattern consists of a bright yellow tail, a body with alternating dark brown and white patches and a dark bar extending from the upper mandible to the operculum. Identification and size ranges of male, female and intersex fish collected from oil platforms were determined in conjunction with gonadal histology. Rock hind social order is haremic with one dominant male defending a territory and a linear dominance hierarchy among individuals. In five captive experiments, the largest remaining female rock hind displayed the male specific color pattern within 32d after dominant male removal from the social group. To our knowledge, this is the first evidence in a grouper species of color patterning used to display territoriality and dominance outside of spawning aggregations. The behavioral paradigm described here is a key advance that will enable mechanistic studies of this complex sex change process.     

Information‐gathering as a response to manipulated signals in the eastern fence lizard,Sceloporus undulatus

Colorful visual signals are used across taxa to convey information during agonistic male‐male encounters, which are important for sexual selection. Although much is known about the information content of color signals, less is known about how receivers interpret this information. Here, using territorial Sceloporus undulatus lizards in a natural setting, we examined receiver response to intruders with different color patch sizes to determine (a) if patch size conveys information assessed during male‐male interactions and (b) if/how receivers modulate their behavioral responses to different types of behavioral signals. We found that larger lizards had longer and wider patches, indicating that the size of the patches may be one of the many characteristics of these patches that is used by males to convey information. Free‐ranging subject males also produced more headbob displays in response to intruders with small patches and took marginally longer to react to intruders with large patches. However, we found no differences in the aggressiveness of the response (i.e., fullshows). This indicates that patch size conveys information that is employed during territorial disputes, but that the response is primarily in terms of timing, allowing lizards to gather more information about intruders, instead of aggressive behavior (i.e., fullshows).     

The Behavioral Ecology of Color Vision: Considering Fruit Conspicuity,Detection Distance and Dietary Importance

Primate color vision is well suited for investigating the genetic basis of foraging behavior owing to a clear genotype–phenotype linkage. Finding fruits amid tropical foliage has long been proffered as an adaptive explanation for primate trichromacy, yet there is a dearth of systematic evaluations of frugivory as an ecological selective force. We studied the behavioral ecology of wild capuchins (Cebus capucinus) in northwestern Costa Rica across the annual cycle and modeled the ability of three dichromatic and three trichromatic phenotypes to discriminate fruits from leaves, a task that represents long-distance search for food patches in a tropical forest. Models of the trichromatic phenotypes could correctly discriminate approximately three-quarters of the total capuchin dietary fruits from leaves, including some fruits subjectively classified as having “cryptic” (greenish-brownish) hues. In contrast, models of dichromatic phenotypes could discriminate fewer than one-third of the fruits. This pattern held when we restricted our analysis to only the most heavily consumed diet items, preferred foods, or seasonally critical species. We in addition highlight the potential of fruit species with small patch sizes to confer an advantage to trichromats, as these resources are anticipated to provide a high finder’s reward. Our results are consistent with the hypothesis that long-distance detection of fruit patches exerts a selective pressure on trichromacy in neotropical primates, and suggest that greenish-brownish fruits might have played an underappreciated role in the evolution of primate color vision.     

Color Vision Variation and Foraging Behavior in Wild Neotropical Titi Monkeys (<Emphasis Type="Italic">Callicebus brunneus</Emphasis>): Possible Mediating Roles for Spatial Memory and Reproductive Status

The selective advantages to primates of trichromatic color vision, allowing discrimination among the colors green, yellow, orange, and red, remain poorly understood. We test the hypothesis that, for primates, an advantage of trichromacy over dichromacy, in which such colors are apt to be confused, lies in the detection of yellow, orange, or red (YOR) food patches at a distance, while controlling for the potentially confounding influences of reproductive status and memory of food patch locations. We employ socially monogamous titi monkeys (Callicebus brunneus) which, like most platyrrhine primates, have polymorphic color vision resulting in populations containing both dichromatic and trichromatic individuals. Wild Callicebus brunneus spent most foraging time in YOR food patches, the locations of most of which were likely to have been memorable for the subjects. Overall, both dichromatic and trichromatic females had significantly higher encounter rates than their dichromatic male pair mates for low-yield ephemeral YOR food patches whose locations were less likely to have been remembered. We detected no difference in the encounter rates of dichromatic and trichromatic females for such patches. However, the data suggest that such a difference may be detectable with a larger sample of groups of Callicebus brunneus, a larger sample of foraging observations per group, or both. We propose that a trichromatic advantage for foraging primates may be realized only when individuals’ energy requirements warrant searching for nonmemorable YOR food patches, a context for selection considerably more limited than is often assumed in explanations of the evolution of primate color vision.     

Negative Association Between Conspicuous Visual Display and Chemosensory Behavior in Two Phrynosomatid Lizards

Communication in one sensory modality can influence communication in others. Lizards in many phrynosomatid species use primarily visual but also chemical signals. The striped plateau lizard, Sceloporus virgatus , exhibits evolutionary loss of a male color signal that in many species is used during aggressive postural displays towards conspecific males. These patches are used similarly in Urosaurus , the sister genus to Sceloporus . We compared a species in which a color signal has been lost, S. virgatus , to a species retaining the ancestral character state of blue abdominal display patches, Urosaurus ornatus , the common tree lizard, to test two hypotheses: (i) conspicuous postural displays that reveal the abdominal patch location are used less in the species that has lost the color patches; and (ii) potential chemical signals are used more in the species with the color loss. We analyzed both visual display behavior (push-up, full-show) and chemosensory behavior (tongue flick and nose tap) of male lizards following their introduction to a resident conspecific male in his home terrarium. Resident males performed very low rates of all behaviors, but intruders exhibited sufficient behavior for analysis.
Supporting the first hypothesis, S. virgatus were less likely than U. ornatus to perform full-show, a display that reveals abdominal skin. Male S. virgatus were more likely to perform push-up than U. ornatus , although S. virgatus performed push-up infrequently. Push-up is a postural display that does not specifically reveal the abdominal patch location. Supporting the second hypothesis, S . virgatus were more likely to perform chemosensory behaviors and performed them at a greater rate than did U. ornatus . Work comparing more closely related species is warranted to determine whether a negative association between conspicuous visual displays and chemosensory behavior is a general pattern.     

黑河上游高寒退化草地狼毒种群小尺度点格局分析

植被斑块化是自然界的一种普遍现象, 斑块的形成和变化对植物种群格局的形成和变化具有重要影响。在黑河上游祁连山北坡高寒退化草地, 采用点格局分析方法, 研究了小尺度上狼毒(Stellera chamaejasme)种群的种群密度、组成格局以及分布格局。结果表明: 随着狼毒种群分盖度的增大, 种群密度、领地密度和组成格局呈现规律性的变化, 斑块内部狼毒种群的数量出现增减交替变化趋势, 组成格局规律明显; 狼毒种群的分布格局表现出与尺度关联的变化趋势, 在31%-40%分盖度下, 狼毒种群在所有尺度上表现为随机分布, 在41%-50%、51%-60%、61%-70%、71%-80%分盖度下随着尺度增大, 分布格局的基本模式为: 随机—聚集—随机或均匀—随机—聚集—随机分布, 在聚集状态下, 聚集强度不同。以成株为核心的斑块内部种群表现为随机分布或均匀分布, 相对于外部表现为聚集分布, 随着成株个体数量的逐渐增多, 种群竞争关系由种间竞争转化为种内竞争, 促进了斑块扩张与合并、斑块增多与吞并, 从而实现了种群扩散。     

黑带食蚜蝇体色变异的研究

通过对黑带食蚜蝇Episyrphus balteatus(De Geer)体色变异的研究,发现黑带食蚜蝇存在深色型和浅色型2种基本形式,体色变异具有明显的季节性,深色型个体出现在温度较低的秋季及早春,浅色型个体发生在温度较高的春夏季节;在腹部色斑方面,深色型和浅色型个体中均存在变异,可划分为8种类型,腹部色斑的变异在浅色型个体中较为丰富,腹部不同体节背板上色斑的变异程度不同;黑带食蚜蝇在体型大小方面同样存在差异,这些变异的多态性可能是食蚜蝇系统学研究中异名产生的一个重要原因。因此,食蚜蝇类群的个体体色变异在系统学研究中是一个必须特别注意的问题。     

芦芽山亚高山草甸优势种群和群落的二维格局分析

种群和群落的二维空间格局研究能够更好地揭示群落的空间和结构特征,但在分析方法上有较大的困难。用垂直相交的两条样带在两个方向上同时取样的二维取样法,获得数据,用一维格局分析方法分别分析,可以得到各个种不同格局规模斑块的长、宽及面积,实现二维格局研究。用DCA排序和格局分析方法相结合,可以完成群落的二维格局分析。在山西芦芽山亚高山草甸应用的结果表明这样的垂直样带二维取样及分析方法较好地反映了种群和群落的空间特性,是非常有效的,并且该方法简单易做,具有较大的可操作性。所研究的草甸主要优势种格局斑块的形状比较规则,面积也较大。次要种斑块多为不规则形,面积也较小。群落格局与主要优势种的格局关系密切。     

Patch structure and ramet demography of the clonal tree, Asimina triloba, under gap and closed-canopy

Clonal understory trees develop into patches of interconnected and genetically identical ramets that have the potential to persist for decades or centuries. These patches develop beneath forest canopies that are structurally heterogeneous in space and time. Canopy heterogeneity, in turn, is responsible for the highly variable understory light environment that is typically associated with deciduous forests. We investigated what aspects of patch structure (density, size structure, and reproductive frequency of ramets) of the clonal understory tree, Asimina triloba, were correlated with forest canopy conditions. Specifically, we compared A. triloba patches located beneath closed canopies and canopy gaps. We also conducted a three-year demographic study of individual ramets within patches distributed across a light gradient. The closed canopy-gap comparison demonstrated that the patches of A. triloba had a higher frequency of large and flowering ramets in gaps compared to closed-canopy stands, but total ramet density was lower in gaps than in closed canopy stands. In the demographic study, individual ramet growth was positively correlated with light availability, although the pattern was not consistent for all years. Neither ramet recruitment nor mortality was correlated with light conditions. Our results indicate that the structure of A. triloba patches was influenced by canopy condition, but does not necessarily depend on the responses of ramets to current light conditions. The lack of differences in ramet recruitment and mortality under varying canopy conditions is likely to be a primary reason for the long-term expansion and persistence of the patches. The primary benefit of a positive growth response to increasing light is the transition of relatively small ramets into flowering ramets within a short period of time.