Color Pattern Research Articles

Crypsis by background matching and disruptive coloration as drivers of substrate occupation in sympatric Amazonian bark praying mantises

Background matching and disruptive coloration are common camouflage strategies in nature, but few studies have accurately measured their protective value in living organisms. Amazon's Bark praying mantises exhibit colour patterns matching whitish and greenish-brown tree trunks. We tested the functional significance of background matching and disruptive coloration of different praying mantis morphospecies (white, grey and green) detected by DNA barcoding. Through image analysis, avian visual models and field experiments using humans as potential predators, we explored whether the background occupation of mantises provides camouflage against predation. Data were obtained for individuals against their occupied tree trunks (whitish or greenish-brown) and microhabitats (lichen or bryophyte patches), compared to non-occupied trunks. White and grey mantises showed lower colour contrasts against occupied trunks at the scale of tree trunk, with no differences in luminance contrasts. Conversely, green mantises showed lower colour and luminance contrasts against microhabitats and also exhibited high edge disruption against greenish-brown trunks. The camouflage of white and green mantis models against colour-matching trunks increased search time and reduced encounter distance of human predators. We highlight the importance of camouflage strategies at different spatial scales to enhance individual survival against predators. Specifically, we present a stunning study system to investigate the relationship of phylogenetically related species that use camouflage in sympatry.

Theory of Reasoned Action : Purchasing Behavior of Batik Jambi

One uniqueness that can be identified as a historical heritage in Indonesia is Batik. Almost every region in Indonesia has its characteristics, including motifs, color patterns, and philosophical meanings. In Jambi, Batik is always worn on formal occasions and has even become the community's uniform at various events. On the other hand, in terms of sales, MSMEs must maintain their brand quality and compete competitively in the market. Therefore, this study investigates consumers' brand image, attitude, and intention to buy Batik and the decision of consumer behavior to buy Batik as an implementation of the Theory of Reasoned Action (TRA). One hundred eighty-eight participants from Jambi province participated in filling out this online questionnaire. Then, the data that has been collected is tested using PLS-SEM. The results showed that all elements of TRA had a positive effect on the buying behavior of Batik in Jambi.

Light-specific wavelengths differentially affect the exploration rate, opercular beat, skin color change, opsin transcripts, and the oxi-redox system of the longsnout seahorse Hippocampus reidi

Light is a strong stimulus for the sensory and endocrine systems. The opsins constitute a large family of proteins that can respond to specific light wavelengths. Hippocampus reidi is a near-threatened seahorse that has a diverse color pattern and sexual dimorphism. Over the years, H. reidi's unique characteristics, coupled with its high demand and over-exploitation for the aquarium trade, have raised concerns about its conservation, primarily due to their significant impact on wild populations. Here, we characterized chromatophore types in juvenile and adult H. reidi in captivity, and the effects of specific light wavelengths with the same irradiance (1.20 mW/cm2) on color change, growth, and survival rate. The xanthophores and melanophores were the major components of H. reidi pigmentation with differences in density and distribution between life stages and sexes. In the eye and skin of juveniles, the yellow (585 nm) wavelength induced a substantial increase in melanin levels compared to the individuals kept under white light (WL), blue (442 nm), or red (650 nm) wavelengths. In addition, blue and yellow wavelengths led to a higher juvenile mortality rate in comparison to the other treatments. Adult seahorses showed a rhythmic color change over 24 h, the highest reflectance values were obtained in the light phase, representing a daytime skin lightening for individuals under WL, blue and yellow wavelength, with changes in the acrophase. The yellow wavelength was more effective on juvenile seahorse pigmentation, while the blue wavelength exerted a stronger effect on the regulation of adult physiological color change. Dramatic changes in the opsin mRNA levels were life stage-dependent, which may infer ontogenetic opsin functions throughout seahorses' development. Exposure to specific wavelengths differentially affected the opsins mRNA levels in the skin and eyes of juveniles. In the juveniles, skin transcripts of visual (rh1, rh2, and lws) and non-visual opsins (opn3 and opn4x) were higher in individuals under yellow light. While in the juvenile's eyes, only rh1 and rh2 had increased transcripts influenced by yellow light; the lws and opn3 mRNA levels were higher in juveniles' eyes under WL. Prolonged exposure to yellow wavelength stimulates a robust increase in the antioxidant enzymes sod1 and sod2 mRNA levels. Our findings indicate that changes in the visible light spectrum alter physiological processes at different stages of life in H. reidi and may serve as the basis for a broader discussion about the implications of artificial light for aquatic species in captivity.

How We Found Three New Species of Penguins

Usually, it is easy to tell species apart by what they look like, for example, a blue whale and a horse. Chinstrap and Adelie penguins are closely related species, but we can still tell them apart by their unique color patterns. However, sometimes different species look incredibly similar, and we must use special methods to tell them apart. These are called cryptic species. Gentoo penguins live across a large area, including Antarctica and many sub-Antarctic Islands. It has been suspected that gentoos might really be more than one species. To test this, we looked at their DNA and measured their flippers, legs, and beaks to compare gentoos living in four locations. We found differences that told us that there are at least four species of gentoo penguins, not just one species as previously thought.

The wing interference patterns (WIPs) of Parapanteles (Braconidae, Microgastrinae): demonstrating a powerful and accessible tool for species-level identification of small and clear winged insects

Wing interference patterns (WIPs) are color patterns of insect wings caused by thin film interference. Thin film interference is the same phenomenon responsible for the refracted spectral colors sometimes visible on soap bubbles. Insect WIPs are static patterns due to the variable thickness of wing membranes and the colors produced depend on the thicknesses of wing membranes. While WIPs have been studied in several taxa of small insects, they have not been broadly adopted by insect taxonomists. We surveyed WIPs in one moderate-sized genus of parasitoid wasps, Parapanteles (Braconidae: Microgastrinae). Using an inexpensive microscope camera set-up and free imaging and analysis software, we detected consistent WIP differences between Parapanteles species. In some cases, WIPs can be used to diagnose sibling species that would otherwise require SEM images to differentiate or DNA barcodes. Wing interference patters are an underemployed character that may be similarly useful in many other taxa of small clear-winged insects.

Effect of preharvest conditions on cut-flower quality.

The cut flower industry has a global reach as flowers are often produced in countries around the equator and transported by plane or ship (reefer) mostly to the global north. Vase-life issues are often regarded as linked to only postharvest conditions while cultivation factors are just as important. Here, we review the main causes for quality reduction in cut flowers with the emphasis on the importance of preharvest conditions. Cut flower quality is characterised by a wide range of features, such as flower number, size, shape, colour (patterns), fragrance, uniformity of blooming, leaf and stem colour, plant shape and developmental stage, and absence of pests and diseases. Postharvest performance involves improving and preserving most of these characteristics for as long as possible. The main causes for cut flower quality loss are reduced water balance or carbohydrate availability, senescence and pest and diseases. Although there is a clear role for genotype, cultivation conditions are just as important to improve vase life. The role of growth conditions has been shown to be essential; irrigation, air humidity, and light quantity and quality can be used to increase quality. For example, xylem architecture is affected by the irrigation scheme, and the relative humidity in the greenhouse affects stomatal function. Both features determine the water balance of the flowering stem. Light quality and period drives photosynthesis, which is directly responsible for accumulation of carbohydrates. The carbohydrate status is important for respiration, and many senescence related processes. High carbohydrates can lead to sugar loss into the vase water, leading to bacterial growth and potential xylem blockage. Finally, inferior hygiene during cultivation and temperature and humidity control during postharvest can lead to pathogen contamination. At the end of the review, we will discuss the future outlook focussing on new phenotyping tools necessary to quantify the complex interactions between cultivation factors and postharvest performance of cut flowers.

Hierarchical Assembly of Patternable Chiroptical Biotextiles with Extreme Environment Stability.

Flexible photonic textiles constructed by sustainable cholesteric organization are very promising to achieve a combination of chiroptical structural colors, mechanical robustness, sustainability, and environment stability. However, the efficient assembly of well-ordered cholesteric nanoarchitectures on flexible textiles in a scalable and patternable manner remains a grand challenge. In this study, we develop an efficient and scalable approach to construct large area chiroptical biotextiles using renewable and bioenabled cellulose nanocrystals (CNCs) as building blocks. This hierarchical assembly enables cholesteric photonic CNCs "cast" in situ, in a seamlessly tessellated design, onto topography-tailored textiles to form a strong interlocked multilayered structure. The resulting hierarchical architecture not only comprises strong photonic-photonic coupling to synergistically enhance the chiroptical properties with tunable wavelengths but also leads to impressive mechanical and optical stability against external mechanical forces and extreme environments. More importantly, through regulating the localized photonic band of the preformed chiroptical textiles by small molecules (e.g., water and glucose), customized colored patterns can be easily generated in large scale that are highly responsive to multistimuli, including chiral polarized light, view angle, and solvent. This chiroptical biotextile is a promising next-generation biomimetic photonic material for defense, aviation, and marine and aerospace special applications.

Ocean Color Image Sequences Reveal Diurnal Changes in Water Column Stability Driven by Air–Sea Interactions

The southward propagation of cold-air frontal boundaries into the Gulf of Mexico region initiates a cascade of coupled air–sea processes that manifests along the coastlines as an apparent brightness anomaly in the ocean color signals. Our hypothesis is that the color anomaly is largely due to the turbulent resuspension of sedimentary particles. Initially, there is significant wind-driven ocean turbulence as the frontal boundary passes, followed by the potential for sustained convective instability due to significant heat losses from the ocean surface. These cold front events occur during boreal autumn, winter, and into early spring, and the latter episodes occur in the context of the seasonally recurring thermal stratification of shelf waters. Here, we show that as stratification reasserts thermal stability in the waning days of a cold front episode, daily to hourly ocean color patterns are temporally coherent with the air–sea heat flux changes and the resulting impact on water column stability. Concomitant results from a nested, data-assimilative, and two-way coupled ocean-atmosphere numerical modeling system provides both corroboration and insight into how surface air–sea fluxes and in-water turbulent mixing manifest as hourly changes in apparent surface water turbidity due to the potential excitation and settling of reflective particles. A simple model of particle mixing and settling driven by the simulated turbulence mimics patterns seen in the satellite image sequences. This study offers a preview of potential application areas that may emerge following the launch of a dedicated ocean color geostationary sensor.

Taxonomic Morphology of Biting Midges (Diptera: Ceratopogonidae)

Ceratopogononidae is a family of small nematocerous flies ranging approximately 1 to 3mm in length. Ceratopogonidae which was previously categorised as a subfamily of Chironomidae is distinguised by the presence of its biting mouthparts. Ceratopogonids commonly known as biting midges are the vectors of numerous pathogens such as viruses, protozoans and nematodes. Hence its transmission has a great veterinary and medical importance. This family is divided into four subfamilies: Leptoconopinae, Forcipomyiinae, Dasyhilinae and Ceratopogoninae. The flies were collected with the help of aspirator, Diptera net and UV light trap. The collected specimens were preserved in the 70% ethanol and later dissected out with the help of Digital Motic Dissecting Binocular. Ceratopogonidae include widely diversified morphotaxanomic character describing various subgroups. This variable character which include colour pattern, sizes of the body, proportions of various morphological parts are not very reliable for taxonomic identification. The study found that the morphotaxanomic feature like external genitalia of male and female, armature and arrangement of wing venation are much more stable. There are several puzzling problems in the determination of disputed species, can be resolved on the basis of taxonomic characters of male and female genitalia. The present paper will resolve the problem related to plethora of taxonomic character with special reference to biting midges.

Meningkatkan Motorik Halus Anak Usia Dini Melalui Kegiatan Meronce

The aim of the research is to improve fine motor skills through ronce activities at Cendrawasih Sukmajaya Early Childhood Education. The research was carried out with classroom actions carried out in two subject cycles for 10 students. The results of observations of initial abilities in the pre-cycle showed that there were 7 children whose fine motor skills had not yet developed (70%) and 3 children who were starting to develop them (30%). In cycle I, there were 6 children who started to develop (60%) and 4 children (40%) who developed according to expectations. Then in cycle II, 2 children (20% of children) developed according to expectations and 8 children (80%) developed very well. This means that there is an increase in students' fine motor skills in implementing classroom action research. This research was stopped until cycle II because it had met the success indicator criteria. Conclusion: meronce activities can improve and increase fine motor skills, namely being able to follow the size of color patterns and students' work.

Analyzing Morphology, Metabolomics, and Transcriptomics Offers Invaluable Insights into the Mechanisms of Pigment Accumulation in the Diverse-Colored Labellum Tissues of Alpinia.

Alpinia plants are widely cherished for their vibrant and captivating flowers. The unique feature of this genus lies in their labellum, a specialized floral structure resulting from the fusion of two non-fertile staminodes. However, the intricate process of pigment formation, leading to distinct color patterns in the various labellum segments of Alpinia, remains a subject of limited understanding. In this study, labellum tissues of two Alpinia species, A. zerumbet (yellow-orange flowers) and A. oxyphylla (white-purple flowers), were sampled and analyzed through morphological structure observation, metabolite analysis, and transcriptome analyses. We found that hemispherical/spherical epidermal cells and undulate cell population morphology usually display darker flower colors, while flat epidermal cells and cell populations usually exhibit lighter flower colors. Metabolomic analysis identified a high concentration of anthocyanins, particularly peonidin derivatives, in segments with orange and purple pigments. Additionally, segments with yellow pigments showed significant accumulations of flavones, flavanols, flavanones, and xanthophylls. Furthermore, our investigation into gene expression levels through qRT-PCR revealed notable differences in several genes that participated in anthocyanin and carotenoid biosynthesis among the four pigmented segments. Collectively, these findings offer a comprehensive understanding of pigmentation in Alpinia flowers and serve as a valuable resource for guiding future breeding efforts aimed at developing Alpinia varieties with novel flower colors.

A framework to generate local spectral skies for spectral daylight simulations

Spectral daylight simulations are becoming increasingly important in predicting non-visual responses to light and more accurate daylight colour and temporal patterns. However, the availability of locally measured spectral sky data is limited and current spectral sky models do not capture the local colour variability of skies. This paper presents a novel framework for generating high-accuracy, location-specific spectral sky data using typically measured atmospheric data at meteorological stations as inputs to physics-based radiative transfer programs like libRadtran. A comparison of measured and simulated data across the year demonstrates that using location-specific atmospheric profiles leads to significantly more accurate predictions of irradiances, spectral global and direct irradiances, and better captures the variability of clear skies regarding colour accuracy and appearance than simulations with default settings.

Description of life cycle and immature stages of Yphthimoides celmis (Godart, [1824]) (Lepidoptera: Nymphalidae: Satyrinae): a contribution to the taxonomic status of the genus.

This article describes the immature stages of the satyrid butterfly Yphthimoides celmis (Godart) for the first time. Morphology, head and body chaetotaxy, and coloration patterns are compared with those of other Yphthimoides species. Larvae behavioral aspects and oviposition behavior are also documented here. Overwintering larvae are observed for the first time for this genus. The larval stage has four or five instars in non-overwintering while six in overwintering larvae. The average duration of the life cycle is around 82 days for non-overwintering, while it is 227 days for overwintering larvae under laboratory conditions. The increase in instar stages and the development time duration of immature stages in overwintering larvae may be due to climatic conditions in the study area and also a strategy to survive the cold season. Eggs have irregular pentagonal and hexagonal cells. First instar larvae have a dark head capsule and a pattern of reddish stripes along their body, with clubbed body setae. Pupae are short and smooth with a non-uniform brown color, presenting a lighter clypeus and a darker ventral portion in the cremaster. We consider that the morphological information of immature stages can improve further phylogenetic studies.

Direct‐Ink‐Written Cholesteric Liquid Crystal Elastomer with Programmable Mechanochromic Response

AbstractCholesteric liquid crystal elastomers (CLCEs) are unique anisotropic rubbers that can change their structural color in response to various stimuli such as heat, chemicals, electric fields, and mechanical stress. Methods such as anisotropic deswelling and surface alignment have been adopted to prepare CLCEs; however, they have limitations in creating spatially controlled CLCE geometries. In this work, a direct ink writing (DIW)‐based 3D‐printable CLCE that can be prepared by extruding viscous CLC ink is developed through a 3D printer nozzle, followed by photopolymerization. Interestingly, the helical axis is inclined to the printing direction by ≈32° due to a combination of the shear‐induced alignment causes during extrusion and the elongational force generated during deposition onto the substrate. This unusual helical axis distortion leads to both blue and red shifts of the reflection color depending on the direction of observation relative to the printing axis. Notably, the printed CLCE exhibits anisotropic mechanochromism upon stretching, because of the stretching‐direction‐dependent variations in the slant angle of the helical axis. This anisotropic mechanochromism can be harnessed to develop a unique CLCE‐based strain sensor displaying intricate color patterns upon stretching, with significant application potential in encryption, anticounterfeiting, and structural health monitoring.

Butterfly eyespots exhibit unique patterns of open chromatin.

Background: How the precise spatial regulation of genes is correlated with spatial variation in chromatin accessibilities is not yet clear. Previous studies that analysed chromatin from homogenates of whole-body parts of insects found little variation in chromatin accessibility across those parts, but single-cell studies of Drosophila brains showed extensive spatial variation in chromatin accessibility across that organ. In this work we studied the chromatin accessibility of butterfly wing tissue fated to differentiate distinct colors and patterns in pupal wings of Bicyclus anynana. Methods: We dissected small eyespot and adjacent control tissues from 3h pupae and performed ATAC-Seq to identify the chromatin accessibility differences between different sections of the wings. Results: We observed that three dissected wing regions showed unique chromatin accessibilities. Open chromatin regions specific to eyespot color patterns were highly enriched for binding motifs recognized by Suppressor of Hairless (Su(H)), Krüppel (Kr), Buttonhead (Btd) and Nubbin (Nub) transcription factors. Genes in the vicinity of the eyespot-specific open chromatin regions included those involved in wound healing and SMAD signal transduction pathways, previously proposed to be involved in eyespot development. Conclusions: We conclude that eyespot and non-eyespot tissue samples taken from the same wing have distinct patterns of chromatin accessibility, possibly driven by the eyespot-restricted expression of potential pioneer factors, such as Kr.

Colour polymorphism associated with a gene duplication in male wood tiger moths.

Colour is often used as an aposematic warning signal, with predator learning expected to lead to a single colour pattern within a population. However, there are many puzzling cases where aposematic signals are also polymorphic. The wood tiger moth, Arctia plantaginis, displays bright hindwing colours associated with unpalatability, and males have discrete colour morphs which vary in frequency between localities. In Finland, both white and yellow morphs can be found, and these colour morphs also differ in behavioural and life-history traits. Here, we show that male colour is linked to an extra copy of a yellow family gene that is only present in the white morphs. This white-specific duplication, which we name valkea, is highly upregulated during wing development. CRISPR targeting valkea resulted in editing of both valkea and its paralog, yellow-e, and led to the production of yellow wings. We also characterise the pigments responsible for yellow, white, and black colouration, showing that yellow is partly produced by pheomelanins, while black is dopamine-derived eumelanin. Our results add to a growing number of studies on the genetic architecture of complex and seemingly paradoxical polymorphisms, and the role of gene duplications and structural variation in adaptive evolution.

Anemonefishes: A model system for evolutionary genomics.

Anemonefishes are an iconic group of coral reef fish particularly known for their mutualistic relationship with sea anemones. This mutualism is especially intriguing as it likely prompted the rapid diversification of anemonefish. Understanding the genomic architecture underlying this process has indeed become one of the holy grails of evolutionary research in these fishes. Recently, anemonefishes have also been used as a model system to study the molecular basis of highly complex traits such as color patterning, social sex change, larval dispersal and life span. Extensive genomic resources including several high-quality reference genomes, a linkage map, and various genetic tools have indeed enabled the identification of genomic features controlling some of these fascinating attributes, but also provided insights into the molecular mechanisms underlying adaptive responses to changing environments. Here, we review the latest findings and new avenues of research that have led to this group of fish being regarded as a model for evolutionary genomics.

Morpho-colorimetric characterization of the perigonium of the Alstroemeria pulchra complex (Alstroemeriaceae, Alstroemerieae) as an aid to delimit its infraspecific taxa

The main taxonomic characters of Alstroemeria derive from the perianth and have traditionally been used from qualitative perspectives, which difficult their interpretation, especially in species considered as infraspecific complexes. Through spectrophotometry and specialized image analysis approaches, a total of one hundred and sixty flowers from twenty populations of the Alstroemeria pulchra complex were quantified. Our results allowed us to recognize the infraspecific taxa A. pulchra subsp. lavandulacea, A. pulchra var. maxima, and A. pulchra var. pulchra through the color, shape, size, and ornamental patterns of their tepals. The colorimetric information subjected to discriminant analysis corroborate the taxonomic utility of flower color. Similar results were obtained from the analysis of ornamental patterns, sizes, and shapes of the tepals. The discriminant analysis of the combined matrix that included the shape and ornamental patterns allowed us to identify three non-overlapping groups within A. pulchra, with a high differentiation degree. These results significantly contribute to improving the understanding of the phenotypic variability of A. pulchra and its infraspecific taxa. This information will serve as a basis for systematic studies that will address the relationships between these and other related taxa from an integrative taxonomic perspective.

Development shapes the evolutionary diversification of rodent stripe patterns.

Vertebrate groups have evolved strikingly diverse color patterns. However, it remains unknown to what extent the diversification of such patterns has been shaped by the proximate, developmental mechanisms that regulate their formation. While these developmental mechanisms have long been inaccessible empirically, here we take advantage of recent insights into rodent pattern formation to investigate the role of development in shaping pattern diversification across rodents. Based on a broad survey of museum specimens, we first establish that various rodents have independently evolved diverse patterns consisting of longitudinal stripes, varying across species in number, color, and relative positioning. We then interrogate this diversity using a simple model that incorporates recent molecular and developmental insights into stripe formation in African striped mice. Our results suggest that, on the one hand, development has facilitated pattern diversification: The diversity of patterns seen across species can be generated by a single developmental process, and small changes in this process suffice to recapitulate observed evolutionary changes in pattern organization. On the other hand, development has constrained diversification: Constraints on stripe positioning limit the scope of evolvable patterns, and although pattern organization appears at first glance phylogenetically unconstrained, development turns out to impose a cryptic constraint. Altogether, this work reveals that pattern diversification in rodents can in part be explained by the underlying development and illustrates how pattern formation models can be leveraged to interpret pattern evolution.

A New Miniature Species of Arthroleptis (Anura: Arthroleptidae) from Nyungwe National Park, Rwanda

A new, very small-sized species of Arthroleptis is described from western Rwanda. The new species occurs locally endemic in Nyungwe Forest and Cyamudongo Forest, where it inhabits the leaf litter of montane forests between 1800 and 2200 m a.s.l. It differs from all other members of the genus by a unique combination of morphological characters, including size (SVL of adult males 16.0–16.5 mm), skin texture, length of hindlimbs, and ventral colour pattern; by characteristics of its advertisement call that consists of a single note lasting 17.4 ± 6.4 [11–32] ms and has a dominant frequency of 5861 ± 188 [5531–6029] Hz; and also in the sequence of the 16S rRNA gene that differs from available homologous sequences of other species of the genus by an uncorrected p-distance of at least 4.6%. Details of the natural history as well as two additional call types are described.