Variation In Coloration Research Articles

The key role of tyrosinase in color variation of the autotetraploid Carassius auratus

The autotetraploid Carassius auratus (4nRR, 4n = 200, RRRR, brownish-yellow coloration), derived from the whole-genome duplication of Carassius auratus red var. (RCC, 2n = 100, RR, red), is a model for understanding the genetics and evolution of polyploid animals. In this study, changes in melanophore and melanin contents indicated differences in melanin metabolism among these two fish species. Tyrosinase (tyr), a key enzyme in melanin biosynthesis, exhibited significant up-regulation in 4nRR, but its role in pigmentation and coloration variation in 4nRR is unknown. Here, color-variant RCC, 4nRR, and their gynogenetic offspring were established and investigated, revealing that 4nRR tyr differentiated from RCC tyr to achieve the effective regulation of 4nRR pigmentation. In RCC, two tyr homeologs have sub-functionalized to synergistically regulate melanogenesis. Furthermore, color variation was tracked at different developmental stages in mutants. Subsequently, four divergent tyr homeologs in 4nRR were localized to four homeologous chromosomes and exhibited predominantly biased expression. Remarkably, yellowish coloration was determined by deficiency of four tyr homeologs rather than single or multiple mutated (<4) homeologs. Further, efficient compensatory regulation was confirmed in mutants, suggesting that all tyr have evolved to cooperatively regulate 4nRR melanogenesis following autopolyploidization. Notably, numerous homozygous gynogenetic offspring were rapidly constructed with stable coloration traits, further demonstrating the regulatory role of tyr homeologs in 4nRR coloration variation, which will enable better generation of novel or tailored strains. These observations reveal a key mechanism underlying coloration formation and variation in 4nRR, while informing skin color–based genetic breeding of polyploid fishes.

Photoregulatory functions drive variation in eye coloration across macaque species

Primates, the most colorful mammalian radiation, have previously served as an interesting model to test the functions and evolutionary drivers of variation in eye color. We assess the contribution of photo-regulatory and communicative functions to the external eye appearance of nine macaque species representing all the branches of their radiation. Macaques’ well described social structure and wide geographical distribution make them interesting to explore. We find that (1) the posterior option of the anterior eyeball is more pigmented closer to the equator, suggesting photoprotective functions. We also find that (2) the temporal side of the eyeball is more heavily pigmented than the nasal side. This suggests that eyeball pigmentation in macaques is distributed to reduce damage to the corneal limbus. The inclusion of a translocated population of M. fuscata in our analyses also suggests that external eye appearance may change quickly, perhaps owing to phenotypic plasticity. We find no evidence that communicative functions drive variation in external eye appearance in macaques. These results suggest that the amount of light in a species’ environment drives variation in eye coloration across macaque species. Furthermore, the geographical distribution of macaques hints at important factors that have yet to be accounted for, such as the reflectivity of the terrain a given species inhabits.

Exploration of Strawberry Fruit Quality During Harvest Season Under a Semi-Forcing Culture with Plants Nursed Without Chilling.

Strawberry, a profitable crop, adapts well to diverse environments. This study evaluated the stability of fruit quality in different strawberry varieties produced as green plants without chilling during the harvest season in northern Uruguay. The focus was on understanding the impact of harvest date versus agricultural practices (different orchards and growers) on key fruit quality variables such as color, firmness, sugars, and acidity. Results indicated that the INIA Yrupé variety showed greater stability in external coloration and sugar content across harvest dates, suggesting that standardizing fruit coloration is viable under challenging conditions. INIA Guapa consistently met minimum requirements for soluble solids and ratio, with stable acidity and red coloration. Firmness was positively correlated with ratio (r = 0.81) and negatively impacted by rainfall 2-3 days before harvest. The findings suggest that harvest date has a more significant impact on INIA Yrupé fruit quality than growing conditions or practices, with variability observed in firmness and ratio but minimal variation in fruit coloration. These insights highlight the importance of harvest timing for maintaining stable fruit quality traits, which is crucial for breeding programs and ensuring consistent sensory quality and crop profitability.

Altitude and ground brightness explain interpopulation variation in dorsal coloration in a lizard

Abstract Non-signaling functions of coloration include thermoregulation (thermal melanism hypothesis), protection against ultraviolet radiation (photoprotection hypothesis), and concealment from predators (crypsis hypothesis). We investigated whether dorsal coloration in 19 populations of spiny-footed lizards, Acanthodactylus erythrurus, across the Iberian Peninsula varies according to these functions. We captured adult males and females in each population and calculated standardized dorsum brightness estimates from photographs. We also calculated standardized ground luminosity estimates and gathered information on latitude, altitude, mean annual temperature, and mean annual solar radiation for each location. Males showed a higher percentage of black coloration and a more contrasted dorsum than females, suggesting different selection pressures on dorsal coloration in both sexes. Furthermore, males showed a darker dorsum and a higher percentage of black coloration at higher altitudes and when the ground was darker. In contrast, females exhibited a darker dorsum only when the ground was darker and a higher percentage of black coloration only at higher altitudes. We also observed that the variation of dorsum luminosity within males and the variation of dorsum luminosity among females within populations were both positively related to the variation of ground luminosity among different points within locations. Latitude, temperature, and solar radiation were not significantly related to dorsal coloration in either sex. Our results support the photoprotection and crypsis hypotheses in males and, to some extent, in females, whereas the thermal melanism hypothesis is weakly supported in both sexes. These findings suggest that there is local adaptation in the dorsal coloration of the spiny-footed lizard.

Intrapopulation variability in coloration is associated with reproductive season in the crayfish Faxonius virilis

Abstract Animal coloration has a wide range of biological functions and may be subject to different, sometimes conflicting, selective pressures. In crustaceans, the evolution of coloration is relatively unstudied, despite the broad range of colors and color patterns, which includes variability at multiple levels. Freshwater crayfish are known to show color variability within species and populations, as well as intra-individual variability, but the function, if any, of crayfish coloration is largely unknown. Here, I report on an experiment to understand patterns of color variability in the crayfish Faxonius virilis and show that variation is strongly correlated to ontogenetic changes from a summer non-reproductive form to a fall reproductive form. Crayfish showed comparatively little inter- and intra-individual color variation in their non-reproductive form, but substantial variation at both levels in the reproductive form. Transition to the reproductive form was associated with the development of greener or bluer coloration localized to the chelae on a subset of individuals, but these changes showed no clear correlation with sex or body size. Future investigations should focus on determining whether differences in color between individuals in the mating season are associated with any physiological or behavioral differences, or with differential susceptibility to predation.

Sexual color ornamentation, microhabitat choice, and thermal physiology in the common wall lizard (Podarcis muralis).

Common wall lizards (Podarcis muralis) in Italy show a striking variation in body coloration across the landscape, with highly exaggerated black and green colors in hot and dry climates and brown and white colors in cool and wet climates. Males are more intensely colored than females, and previous work has suggested that the maintenance of variation in coloration across the landscape reflects climatic effects on the strength of male-male competition, and through this sexual selection. However climatic effects on the intensity of male-male competition would need to be exceptionally strong to fully explain the geographic patterns of color variation. Thus, additional processes may contribute to the maintenance of color variation. Here we test the hypothesis that selection for green and black ornamentation in the context of male-male competition is opposed by selection against ornamentation because the genes involved in the regulation of coloration have pleiotropic effects on thermal physiology, such that ornamentation is selected against in cool climates. Field observations revealed no association between body coloration and microhabitat use or field active body temperatures. Consistent with these field data, lizards at the extreme ends of the phenotypic distribution for body coloration did not show any differences in critical minimum temperature, preferred body temperature, temperature-dependent metabolic rate, or evaporative water loss when tested in the laboratory. Combined, these results provide no evidence that genes that underlie sexual ornamentation are selected against in cool climate because of pleiotropic effects on thermal biology.

Multiple plumage color signals associated with courtship displays may represent body quality in male golden pheasants (Chrysolophus pictus)

Many animals display numerous colors that can range from red, green, blue, and orange to ultraviolet, whereas others are dull or have a uniform coloration. The reason for this variation in coloration remains unknown. It has been hypothesized that different colors represent multiple signals that either reflect different components, redundant information, or simply no longer provide reliable information regarding body quality. Here, we analyzed the highly diverse coloration of male golden pheasants ( Chrysolophus pictus) using an avian visual model from the avian visual system and related the different components of coloration to several phenotypic traits of body quality. We found that different components of plumage color correlated with the length of the body, tail, spur, and beak, suggesting that the multiple colors in male golden pheasants signal different components of body quality. In particular, tail length was correlated with many aspects of coloration, especially the green and orange colors of neck plumage, which are particularly important because male golden pheasants spread their neck plumage and show it to females during their courtship display. Therefore, these findings reveal that the plumage colors of male golden pheasants encode multiple signals that reflect their body condition during courtship displays.

Disparities in Body Color Adaptability and Ambient Light Color Preference between Wild and Hatchery-Reared Marbled Rockfish (Sebastiscus marmoratus).

Hatchery rearing significantly influences the phenotypic development of fish, with potential adverse effects for the post-release performance of hatchery-reared individuals in natural environments, especially when targeted for stock enhancement. To assess the suitability of releasing hatchery-reared fish, a comprehensive understanding of the phenotypic effects of captive rearing, through comparisons with their wild conspecifics, is essential. In this study, we investigated the divergence in body coloration between wild and hatchery-reared marbled rockfish Sebastiscus marmoratus. We examined the selection preferences for different light colors and assessed the impact of different ambient light colors on the morphological color-changing ability of juvenile marbled rockfish. Our findings revealed significant differences in body color between wild and hatchery-reared marbled rockfish. The hue and saturation values of wild marbled rockfish were significantly higher than those of their hatchery-reared counterparts, indicative of deeper and more vibrant body coloration in the wild population. Following a ten-day rearing period under various light color environments, the color of wild marbled rockfish remained relatively unchanged. In contrast, hatchery-reared marbled rockfish tended to change their color, albeit not reaching wild-like coloration. Light color preference tests demonstrated that wild juvenile marbled rockfish exhibited a preference for a red-light environment, while hatchery-reared individuals showed a similar but weaker response. Both wild and hatchery-reared marbled rockfish displayed notable negative phototaxis in the presence of yellow and blue ambient light. These results highlight the impact of hatchery rearing conditions on the body color and morphological color-changing ability, and provide insight into light color selection preferences of marbled rockfish. To mitigate the divergence in phenotypic development and produce more wild-like fish for stocking purposes, modifications to the hatchery environment, such as the regulation of ambient light color, should be considered.

Environmentally associated colour divergence does not coincide with population structure across Lesser Antillean anoles

Abstract Species distributed across heterogeneous environments may undergo local adaptation, which can be limited by the homogenizing effects of gene flow. Lesser Antillean anoles exhibit dorsal colour variation associated with dramatic shifts in environment across small spatial scales, providing an excellent system for studying the maintenance of local adaptation despite ongoing gene flow. The 1995 Soufriere Hills eruption on Montserrat provides an opportunity to understand how natural disasters may influence the evolution of insular species. Thus, our study had two main objectives. First, we collected genetic, phenotypic, and environmental data to investigate whether environmentally associated dorsal coloration reflects underlying population structure in three species of Lesser Antillean anoles. Second, we examined the short-term evolutionary consequences of volcanism by comparing pre- and posteruption samples of Anolis lividus using multilocus sequence data. We found all three species exhibited genetic isolation-by-distance but not isolation-by-environment. Furthermore, phenotypic differences within each species were not predicted by genetic distances, suggesting gene flow across colour morphs. We confirmed the repopulation of A. lividus in the impacted area and found genetic diversity equivalent to pre-eruption sampling. Our findings contribute to our understanding of local adaptation in spatially small-scale systems and the impact of catastrophic natural disasters on population structure.

Pollinator shift ensures reproductive success in a camouflaged alpine plant.

There are intrinsic conflicts between signalling to mutualists and concealing (camouflaging) from antagonists. Like animals, plants also use camouflage as a defence against herbivores. However, this can potentially reduce their attractiveness to pollinators. Using Fritillaria delavayi, an alpine camouflaged plant with inter-population floral colour divergence, we tested the influence of floral trait differences on reproduction. We conducted pollination experiments, measured floral morphological characteristics, estimated floral colours perceived by pollinators, analysed floral scent and investigated reproductive success in five populations. We found that the reproduction of F. delavayi depends on pollinators. Under natural conditions, a flower-camouflaged population had 100 % fruit set and similar seed set to three out of four yellow-flowered populations. Bumblebees are important pollinators in the visually conspicuous yellow-flowered populations, whereas flies are the only pollinator in the flower-camouflaged population, visiting flowers more frequently than bumblebees. The camouflaged flowers cannot be discriminated from the rock background as perceived by pollinators, but may be located by flies through olfactory cues. Collectively, our results demonstrate that the flower-camouflaged population has different reproductive traits from the visually conspicuous yellow-flowered populations. A pollinator shift from bumblebees to flies, combined with high visitation frequency, compensates for the attractiveness disadvantage in camouflaged plants.

Analysis of Transcriptome and Expression of C4H and FLS Genes on Four Flower Colors of Impatiens uliginosa

Flower color is a major feature of ornamental plants, and the rich flower color of plants is an important factor in determining their ornamental and economic values, so flower color is an important research target for gardening and horticulture breeders at home and abroad. Our research group collected four colors of Impatiens uliginosa (white, pink, red, and deep red) during the collection of germplasm resources in the field. In this study, we analyzed the transcriptomes of the four flower colors of I. uliginosa by using RNA-Seq technology. The transcriptomes were screened to identify candidate genes related to flower color, and the coloring mechanisms of four flower colors were revealed at the molecular level. The main findings were as follows: (1) The number of the four different transcripts ranged from 64,723 to 93,522 and contained a total of 100,705 unigenes. (2) The analysis of differentially expressed genes revealed structural genes including C4H, FLS, PAL, and ANS and transcription factors including MYB, MYB-related, AP2-EREBP, and bHLH. (3) Among the four flower colors of I. uliginosa, the C4H1 gene had the highest expression in pink flowers, and the C4H2 gene had the highest expression in red flowers. This indicated that C4H genes positively regulated the red flower color of I. uliginosa. However, FLS expression was the highest in white flowers, and with deepening flower color, FLS gene expression gradually weakened, acting as a negative regulator. The results of this study could lay the theoretical foundation for investigating the mechanism of coloration and flower color variation in I. uliginosa.

Variation in Ventral Coloration Pattern and Aposematism in Tropical Warty Newts.

Aposematic coloration plays a crucial role in animal defense, and it is shaped by a complex interplay of factors such as physiological limitations and sexual and natural selection. Warty newts within the genus Paramesotriton exhibit significant variation in ventral coloration. In this study, we quantified the percentage of red ventral area to investigate aposematic ventral coloration in Paramesotriton deloustali and P. guangxiensis across eight populations in northern Vietnam. To assess the interaction between predators and the aposematic signals, we conducted experiments employing three types of clay replicas of newts: dorsal, red ventral, and black ventral models. Our findings revealed a significant variation in the red ventral area among different populations. Additionally, a significant correlation was detected between the red ventral area of the newt and the annual temperature range. In clay model experiments, a significant difference in predator attack rates was observed between dorsal and ventral clay models. Interestingly, there was no significant difference in attack rates between red and black ventral types. Our study suggested that the variation in the red ventral area of warty newts is probably influenced by multiple factors, including genetic constraints, sex, ambient environment, and diet. Furthermore, our results supported the effectiveness of displaying aposematic coloration as an antipredator defense mechanism in warty newts. However, variations in body size and the pressure of mammal predation might not play a significant role in determining aposematic coloration.

Integrative Metabolome and Transcriptome Analyses Reveal the Pericarp Coloration Mechanisms in Bitter Melon (Momordica charantia L.)

Pericarp colors are critical agronomic traits that affect the quality and economic values of fruits. Although a diversity of bitter melon pericarp (BMP) colors is available, the fruit pigmentation mechanisms remain elusive. Hence, this study aimed to unveil the key metabolites and molecular mechanisms underlying variation in BMP coloration through integrative metabolomics and transcriptomics analyses of four differently colored genotypes, including K1102 (grayish orange), 262 (grayish yellow), 1392 (very soft green), and K115 (dark grayish cyan). The four BMPs exhibited significant metabolite profile and transcriptional differences, as over 112 and 1865 DAMs (differentially accumulated metabolites) and DEGs (differentially expressed genes), respectively, were identified. The variation in the content of six anthocyanins, including malvidin 3-O-glucoside, petunidin 3-O-glucoside, rosinidin O-hexoside, cyanidin, cyanidin 3-p-hydroxybenzoylsophoroside-5-glucoside, and pelargonidin 3-O-beta-D-glucoside, might be the major driving factor of BMP color changes. Notably, malvidin 3-O-glucoside, rosinidin O-hexoside, and petunidin 3-O-glucoside are the dominant pigments in K115, while carotenoids and other flavonoids may contribute to other colors. Candidate flavonoid structural and regulatory (MYBs, NACs, MADSs, bHLHs, and bZIPs) genes were identified. Of them, gene13201 (anthocyanin reductase), gene8173 (polyphenol oxidase), gene2136 (NAC43), gene19593 (NAC104), and gene15171 (tetrapyrrole-binding protein) might play essential roles in K115 pericarp color development. Our findings deepen our understanding of BMP pigmentation and provide fundamental resources for higher-valued bitter melon breeding perspectives.

Comparison of prey fauna in tropical red traps versus temperate whitish traps in carnivorous Drosera indica complex (Droseraceae)

AbstractCertain carnivorous plant species display geographical variation in trap coloration, which may impact interactions with prey. Our study focused on Drosera indica (Droseraceae) in tropical Thailand and its phylogenetically related species Drosera toyoakensis in temperate Japan. Drosera indica in Thailand has green leaf blades with red tentacles when flowering, making the entire trap appear red. In contrast, D. toyoakensis in Japan has green leaf blades with green‐white tentacles when flowering, and the entire trap appears white. Field observations revealed statistically significant differences in taxa and size of prey caught by D. indica and D. toyoakensis. Both species caught small flies, but D. toyoakensis additionally caught larger flies and butterflies, including pollinators. These differences in prey composition may reflect differences in trap coloration that evolved under different selection pressures for capturing prey. However, trap coloration and prey assemblages were influenced by various factors, and further research is required to elucidate their evolutionary significance.

Red/Orange Autofluorescence in Selected Candida Strains Exposed to 405 nm Laser Light.

Candida albicans and similar species are significant pathogens in immunocompromised and hospitalized individuals, known for mucosal colonization and bloodstream/organ invasion. Many pathogenic fungi, including these species, exhibit autofluorescence (R/OF) under specific light conditions, a feature crucial for their detection. We investigated the use of a 405 nm diode laser for the direct observation of red/orange autofluorescence of Candida spp., common in the oral cavity, exploring its potential in health screenings. This study utilized cultures of Candida spp. on Sabouraud dextrose agar with Qdot 655 and 685 for fluorescence benchmarking, illuminated using a 405 nm diode laser (continuous wave, power 250 mW, 0.0425 J/cm² fluence, 0.0014 W/cm² power density). Images were captured using a yellow-filter camera at set intervals (48 to 144 h). Visual and computational analyses evaluated the R/OF in terms of presence, intensity, coloration, and intra-colony variation. Most Candida strains displayed red/orange autofluorescence at all observation times, characterized by varied coloration and intra-colony distribution. Initially, there was an increase in R/OF intensity, which then stabilized in the later stages of observation. The majority of the Candida strains tested are capable of emitting R/OF under 405 nm laser light. This finding opens up new possibilities for integrating R/OF detection into routine dental screenings for Candida spp.

A late burst of colour evolution in a radiation of songbirds (Passeriformes: Parulidae) suggests secondary contact drives signal divergence.

Evolutionary radiations provide important insights into species diversification, which is especially true of adaptive radiations. New World wood warblers (Parulidae) are a family of small, insectivorous, forest-dwelling passerine birds, often considered an exemplar of adaptive radiation due to their rapid diversification followed by a slowdown. However, they deviate from the expectations of an adaptive radiation scenario due to the lack of conspicuous morphological and ecological differentiation. We fitted several macroevolutionary models to trait data in 105 species of wood warblers. We tested whether morphological traits underwent an early burst of evolution (suggesting adaptation to new ecological niches in adaptive radiations) and whether song and colour underwent a diversity-dependent acceleration of trait evolutionary rate (consistent with reproductive interference driving signal evolution). Morphology and song evolved gradually under stabilizing selection, suggesting niche conservatism, with morphology possibly acting as a constraint on song evolution. In contrast, many feather colour traits underwent a diversity-dependent burst of evolution occurring late in the clade's history. We suggest that a two-step process has led to the remarkable diversification of wood warblers. First, their early diversification probably proceeded by allopatric speciation. Second, feather colour divergence likely occurred during secondary contact after range expansion. This diversification of signalling traits might have facilitated species coexistence, in combination with behavioural niche partitioning. Wood warblers seem to present characteristics of both adaptive and non-adaptive radiations.

Genetically Encoded Lizard Color Divergence for Camouflage and Thermoregulation.

Local adaptation is critical in speciation and evolution, yet comprehensive studies on proximate and ultimate causes of local adaptation are generally scarce. Here, we integrated field ecological experiments, genome sequencing, and genetic verification to demonstrate both driving forces and molecular mechanisms governing local adaptation of body coloration in a lizard from the Qinghai-Tibet Plateau. We found dark lizards from the cold meadow population had lower spectrum reflectance but higher melanin contents than light counterparts from the warm dune population. Additionally, the colorations of both dark and light lizards facilitated the camouflage and thermoregulation in their respective microhabitat simultaneously. More importantly, by genome resequencing analysis, we detected a novel mutation in Tyrp1 that underpinned this color adaptation. The allele frequencies at the site of SNP 459# in the gene of Tyrp1 are 22.22% G/C and 77.78% C/C in dark lizards and 100% G/G in light lizards. Model-predicted structure and catalytic activity showed that this mutation increased structure flexibility and catalytic activity in enzyme TYRP1, and thereby facilitated the generation of eumelanin in dark lizards. The function of the mutation in Tyrp1 was further verified by more melanin contents and darker coloration detected in the zebrafish injected with the genotype of Tyrp1 from dark lizards. Therefore, our study demonstrates that a novel mutation of a major melanin-generating gene underpins skin color variation co-selected by camouflage and thermoregulation in a lizard. The resulting strong selection may reinforce adaptive genetic divergence and enable the persistence of adjacent populations with distinct body coloration.

Iterative taxonomy reveals a new species of Cambeva (Siluriformes: Trichomycteridae) with intraspecific variation from the rio Piquiri and Ivaí basin, upper rio Paraná basin, Brazil

Abstract A new species of Cambeva occurring in the rio Piquiri and Ivaí, upper rio Paraná basin, Brazil, is described using the combination of morphological and molecular data. The new species is distinguished from most congeners by the presence of a notch in the posterior portion of the metapterygoid, number of branchiostegal rays, opercular and interopercular odontodes, and ribs. In addition, the results corroborated the existence of a single species with wide intraspecific variation in body coloration. The type-locality is within the area of influence of the Perobas Biological Reserve, a Conservation Unit in the Paraná State, composed of two Atlantic Forest physiognomic forms. Considering that the upper rio Paraná basin is an area of significant anthropic influence, it is crucial to describe and preserve species to understand their ichthyofauna.

Spectral variation and pigmentary basis of ornamental and mimetic wing colour patches of swallowtail butterflies

Abstract Colours and colour patterns are diverse traits that are often used as visual signals. To test ecological and evolutionary drivers of these visual signals, a clear understanding of their nature and variation is necessary. Here we characterize variation in wing coloration of mormon swallowtail butterflies (Papilio, subgenus Menelaides). These species exhibit two kinds of colour patches on black wings: creamy white/yellow/green patches that are presumably used as sexual ornaments, and pure white patches that are presumably used as mimetic signals. Using reflectance spectrophotometry we quantified spectral properties of black wing background and colour patches between sexes, wing surfaces, and mimicry status. We found that brightness and saturation of the black background were less variable across sexes, wing surfaces, and mimetic/nonmimetic status. However, colour contrast and saturation were higher on dorsal surfaces than on ventral surfaces, and colour contrast between the black background and colour patches was higher in males than in females. Colour patches in nonmimetic butterflies were brighter and more saturated across the whole colour spectrum compared to mimetic butterflies. Thus, our study characterizes colour variation in an extraordinary signal radiation on the wings of swallowtail butterflies, a model clade in ecology, evolution, and genetics. Our results generate numerous hypotheses about the ecological and sexual functions of these colour patches, which may guide further behavioural experiments. Finally, using liquid chromatography-mass spectrometry we identified the pigment papiliochrome-II to be the chemical basis of the presumed sexual ornaments in mormon swallowtails.

Identification and effective regulation of scarb1 gene involved in pigmentation change in autotetraploid Carassius auratus.

The autotetraploid Carassius auratus (4nRR, 4 n=200, RRRR) is derived from whole-genome duplication of Carassius auratus red var. (RCC, 2 n=100, RR). In the current study, we demonstrated that chromatophores and pigment changes directly caused the coloration and variation of 4nRR skin (red in RCC, brownish-yellow in 4nRR). To further explore the molecular mechanisms underlying coloration formation and variation in 4nRR, we performed transcriptome profiling and molecular functional verification in RCC and 4nRR. Results revealed that scarb1, associated with carotenoid metabolism, underwent significant down-regulation in 4nRR. Efficient editing of this candidate pigment gene provided clear evidence of its significant role in RCC coloration. Subsequently, we identified four divergent scarb1 homeologs in 4nRR: two original scarb1 homeologs from RCC and two duplicated ones. Notably, three of these homeologs possessed two highly conserved alleles, exhibiting biased and allele-specific expression in the skin. Remarkably, after precise editing of both the original and duplicated scarb1 homeologs and/or alleles, 4nRR individuals, whether singly or multiply mutated, displayed a transition from brownish-yellow skin to a cyan-gray phenotype. Concurrently, the proportional areas of the cyan-gray regions displayed a gene-dose correlation. These findings illustrate the subfunctionalization of duplicated scarb1, with all scarb1 genes synergistically and equally contributing to the pigmentation of 4nRR. This is the first report concerning the functional differentiation of duplicated homeologs in an autopolyploid fish, substantially enriching our understanding of coloration formation and change within this group of organisms.