Variation in eye pigmentation across primate species has been proposed to serve as a cue to emotional or temperamental traits, potentially shaped by processes like domestication or selection against aggression. We tested whether pygmy marmosets (Cebuella pygmaea) respond differently to conspecific facial images that vary in peri-iridal pigmentation. Specifically, we examined whether darker peri-iridal pigmentation elicits more distress or aversive reactions, consistent with the hypothesis that eye colouration serves as a signal of underlying temperament. Contrary to predictions, subjects did not exhibit differential behavioural responses to stimuli depicting conspecifics with light, or dark peri-iridal tissue, or control stimuli. These results align with emerging evidence that challenges the presumed association between ocular pigmentation and temperament or aggression levels in primates. We discuss potential explanations, including species-specific differences in tolerance to eye contact, generalized arousal to experimental contexts, and the need for more controlled comparisons. While our findings do not support a signalling function for eye pigmentation in this context, they contribute to a broader reassessment of the proposed links between morphology and socio-emotional traits in primates.

The aim of the study was to evaluate calcium anacardate (CAn), associated or not with citric acid (CAc) in laying hen diets on performance, egg quality, serum biochemical profile, serum lipid peroxidation (TBARS) and catalase (CAT) in reproductive tissue. A total of 432 laying hens from 63 to 74 weeks of age, were distributed in nine diets: Control; 0.25% CAn; 0.25% of CAn associated with 0.25% CAc; 0.50% CAn; 0.50% CAn associated with 0.25% CAc; 0.50% CAn associated with 0.50% CAc; 0.75% of CAn; 0.75% CAn associated with 0.25% CAc; 0.75% CAn associated with 0.50% CAc. There was no effect of CAn or CAc on laying hen performance. Yolk colour showed greater pigmentation for 0.75% CAn and its associations with CAc (0.25% and 0.50%). Lower egg yolk oxidation was observed for an isolated dose of 0.75% CAn. Higher values of TBARs were observed in eggs from birds fed control diet; 0.25% CAn; 0.50% CAn associated with 25% CAc and 0.75% CAn associated with 0.25 and 0.50% CAc. Dietary inclusion of CAn (0.75%) and its association with CAc (0.50% CAn with 0.50 CAc) for late-phase laying hens reduce serum peroxidation. CAn from 0.50% associated with CAc increases catalase in magnum. The addition of 0.75% CAn increases yolk pigmentation, reduces lipid oxidation in the yolk and blood plasma and increases CAT activity in the magnum in late-stage laying hens. These benefits can also be obtained with the combination of 0.50% CAn and 0.50% CAc.

Anthuroid isopods in the genus Mesanthura (52 valid species) typically have a body with conspicuous dorsal pigmentation, with differences in the female pigmentation pattern being one of the main characters used to distinguish species. Five Mesanthura species have been reported to date from Japan. Here, we describe Mesanthura sol sp. nov. from Irabu Island and Okinawa main island, Okinawa, Japan, and illustrate its sexual dimorphism in colour pattern, with conspecificity between males and females confirmed with molecular data. We provide a description of Mesanthura miyakoensis based on specimens collected from Kochi, Shikoku, Japan. We present the first records of Mesanthura cinctula and Mesanthura nigrodorsalis, following their original descriptions. Finally, we provide partial sequences of the 16S rRNA gene for these four species and present a phylogenetic tree based on the sequences.

Genes involved in melanin production directly impact insect pigmentation and can affect diverse physiology and behaviours. The role these genes have on sex behaviour, however, is unclear. In the present study, the crucial melanin pigment gene black was functionally characterised in an urban pest, the German cockroach, Blattella germanica. RNAi knockdown of B. germanica black (Bgblack) had no effect on survival, but did result in black pigmentation of the thoraxes, abdomens, heads, wings, legs, antennae, and cerci due to cuticular accumulation of melanin. Sex-specific variation in the pigmentation pattern was apparent, with females exhibiting darker coloration on the abdomen and thorax than males. Bgblack knockdown also resulted in wing deformation and negatively impacted the contact sex pheromone-based courtship behaviour of males. This study provides evidence for black function in multiple aspects of B. germanica biology and opens new avenues of exploration for novel pest control strategies.

A new record of a white humpback whale (Megaptera novaeangliae) was made off Papeete, Tahiti in July 2019. The individual was completely white, except for grey patterns on its body and on the ventral part of the fluke. The presence of different colourations indicates that this individual is not an albino but a leucistic individual. According to field observations, the individual was likely a juvenile or a subadult. It was seen breaching several times and travelled further north of Papeete, where the animal was recaptured off Arue. White individuals are rare and offer unique opportunities to understand whale movement patterns and potential population connectivity among humpback whale populations.

Garra gotyla is an indigenous coldwater fish of the cyprinid family and has wide geographical distribution in India as well as in other countries of Asia and Africa. Induced breeding in G. gotyla was carried out successfully for the first time and an attempt has been made to document developmental stages chronologically from the first minute of fertilization, through all stages of embryonic development until the fifth day post hatching. This experiment was carried out at 22–24°C water temperature at the Directorate of Coldwater Fisheries Research, Bhimtal, India. During the breeding trial, the fertilization rate was observed as 70–75% and hatching rate was 85–90%. The mature fertilized ova were measured as 0.8–1.0 mm in diameter and the perivitelline membrane became thick soon after fertilization and formation of the germ pole. The periods taken for complete developmental stages were recorded; cleavage stage 111 min (min post fertilization (pf)), blastulation stage 580 min (pf), neurulation and segmentation 1250 min (pf) and hatching was completed after 1420 min. The sac fry was measured as 3 mm in length and took almost 3 days for complete absorption of the yolk content. The major structural and differential changes observed are in head, tail, fins, alimentary canal, rudiments of each organ and appearance of melanophore pigmentation in the whole body. The 5-day-old larvae were measured as 6 mm in length with almost every organ fully differentiated. The present study will be utilized for large-scale production of fingerlings for stock enhancement in rivers, lakes and possibilities of genetic improvement and manipulation at the embryonic stage.

Is darker skin pigmentation associated with less favorable social and political outcomes in Latin America? We leverage data from 18 Latin American countries across multiple survey waves to demonstrate the robust and potent negative relationship between the darkness of skin tone and socio-economic status. Then we examine the relationship between skin color and attitudes toward the political system. In spite of our substantial sample size, we find little support for the expectation that respondents with darker skin are less favorably disposed toward the political system—indeed, on balance, our findings run counter to this expectation. Our findings suggest that the socio-economic “pigmentocracy” that pervades the region does not necessarily translate into pronounced differences in attitudes about the political system. This finding casts some doubt on the expectation that social inequalities are likely to destabilize governments or undermine their legitimacy.

Faba bean (Vicia faba L.) is a valuable grain legume and a staple protein crop in many countries. Its large and complex genome requires novel approaches for its genetic dissection. Here we introduce a multi-parent population developed from four founders (ILB 938/2, Disco/2, IG 114476 and IG 132238). The selection of parental lines was based on geographic (Colombia, France, Bangladesh and China), genetic and phenotypic diversity. The parental lines were inbred and then genotyped using 875 single nucleotide polymorphism (SNP) markers. Based on molecular data, the parents had high homozygosity and high genetic distance among them. The population segregates for several important traits such as seed morphology, seed chemistry, phenology, plant architecture, drought response, yield and its components, and resistance to Botrytis fabae. The population was checked for unbiased segregation in each generation by observing simply inherited Mendelian traits such as stipule spot pigmentation (SSP) and flower colour at different generations. All 1200 four-way cross F1 plants had pigmented flowers and stipule spots. The segregation ratios for white flower colour (single gene, zt2) fit 7:1, 13:3 and 25:7 at F2, F3 and F4 generations, respectively, and the segregation ratio of SSP (two recessive unlinked genes, ssp1 and ssp2) fit 49:15 and 169:87 at the F2 and F3 generations, respectively, demonstrating unbiased generation advance. We will subject the F5 generation of this population to a high-throughput SNP array and make it available for further phenotyping and genotyping.

This study documents the presence of crypsis in Mugil curema juveniles under laboratory culture. Initially, the juveniles were located in one brown tank (BT1), later almost half of the individuals were placed in a white tank (WT) where they showed a pigmentation change to white. After being moved to another brown tank (BT2), the juveniles changed to their brown original colour, but kept a few small white spots on the dorsal axis of the body. The ventral head melanophore pattern also changed in the white specimens. Temperature (°C), oxygen (mg l−1) and Illuminance light (Lux m−2), total length (mm) and total weight (g) were determined by tank. Chromaticity was measured in L*(relative luminance) a*(measurement relating to the redness or greenness of the light) b*(measurement relating to the yellowness or blueness of the light) coordinates where all three values are required to completely describe an object’s colour. One-way ANOVA showed no differences for temperature, oxygen and illuminance light among tanks. Length and weight were similar for BT1 and WT but both were different from BT2. The white juveniles depicted similar L* as the WT background as well as the dorsal area of the brown pigmentation and converted juveniles to the brown tanks BT1 and BT2, respectively. Therefore, the fish's body relative luminance matches the background. To our knowledge this behaviour has not been reported before for any fish mullet either cultured or living in the wild.

Hair colouration in animals is controlled primarily by inherited factors, with a complex set of genes and genetic variants determining phenotypic expression. The colours in the hair shaft are created initially by the melanocyte cells within the hair bulb which produce and secrete two types of melanin into the hair cortex, black eumelanin and brown pheomelanin. Together these two pigments are responsible for creating the considerable diversity of colour seen in hair across the animal kingdom. In the absence of melanins the hair remains translucent, appearing white to the eye. Colour, or absence thereof, can only be imparted on a hair during its ‘anagen’ or growing phase. During the telogen (resting) phase the colour of the hair is relatively constant, notwithstanding effects of environmental influences such as UV in sunlight, or staining agents. A further environmental factor is nutrition. The intensity of black in the hair of both cats and dogs is known to be influenced by the dietary intake of certain amino acids such as phenylalanine (Phe) and tyrosine (Tyr). However the role of nutrition in hair pigmentation is generally poorly understood. This trial investigated the impact of diet on the commonly observed red discolouration of white coat in dogs. Two panels of 13 Swiss White Shepherd dogs were fed diets containing different concentrations of Phe + Tyr (test diet containing 3.02 g/Mcal versus control 4.82 g/Mcal) and copper (test diet containing 8.93 ppm versus control 13.28 ppm) for four months. Coat colouration was assessed via spectrophotometry using the CIE Lab colour space system (International Commission on Illumination). Dogs fed the reduced Phe + Tyr and copper showed significantly less red coat pigmentation (a* parameter) by the end of the feeding study (P < 0.02). It was concluded that the level of Phe + Tyr not only affects black but also white coat in dogs. Diet can therefore exert an influence on multiple aspects of coat pigmentation.

This study reports the first occurrence of partial albinism in a tropical anguillid eel Anguilla bengalensis bengalensis from Malaysia. This paper also describes the first record of albinism in the genus Anguilla. The occurrence of albinism in our specimen of Anguilla might have been caused by three factors: (1) contamination effects; (2) random genetic alterations; or (3) genetic alteration due to small population size. The present results suggest that the albinism in A. bengalensis bengalensis is probably caused by random genetic alteration. Partial albinism may not be a handicap in the life of the present specimen because the eel could still potentially grow to more than 1 m in total length, just like a normal adult eel.

Hatchlings of clown loach (3.8 mm in total length, TL) are pelagic. Whenreared at 26−28 °C, they become benthic 3 days after hatching (dah), when their swimbladder is inflated. The fin development sequence (pectorals  <  caudal  < dorsal  =  anal  <  pelvic) is typical of the clade Ostariophysi. All fins andfinrays are fully elongated at 20 mm TL, but the finfold persists until25 − 26 mm TL (start of juvenile stage). Melanophores appear at 3 dah,they form a 5-bar pattern at 5 dah, then two bars (III and V) vanish progressively,producing at 26 mm TL the 3-bar pattern that is typical of adults.Throughout the ontogeny, the pigment pattern exhibits a structural regularity (bars spacedat regular intervals), which is interpreted in a functional perspective by reference tothe maintaining of crypsis and signalling throughout. Exogenous feeding commences at 4 dah(5.5 mm TL). Food intake (FI) increases rapidly, from 6%wet body mass (WM) at 5.5 mm TL to  >20%WM in fish  > 7 mm TL. Gut evacuation rate(Rg) increases with increasing meal sizeand fish size, as a result of gut coiling (from 8 to 15 mm TL), and ishighest at 11 mm TL (about 10% WM h-1 in fishfeeding maximally). The allometric increase of FI andRg during the early larval stages isaccompanied by increasing capacities for growth, so early sizes differences amplifyrapidly during the ontogeny. Nevertheless, growth remains slow (mean of 0.4 mm TLday-1 from 4 to 29 dah; 0.9 mm TL day-1for top growers). By contrast, unfed fish display long resistance to starvation (until14−15 dah). The combination of slow growth and long resistance to starvation is discussedin respect to the reproductive phenology of the species, as the capacity of makingmetabolic economies prevails over fast growth for seasonal strategists spawning mainly atthe start of the rainy season.

Functional agro biodiversity defines the exploitation of biodiversity to provide ecosystem services, support sustainable agricultural production and benefit the regional and global environment and the public at large (ELN-FAB, 2009; www.eln_fab.eu). Tracking of animal products back to the breed of origin based on their genetic make-up undoubtedly falls in this category. The aim of this paper was to identify and validate a set of single nucleotide polymorphisms (SNPs) in goat coat colour genes, most of which have not been investigated before, to trace five goat populations of the Italian Alps and their product. Several regions of 28 genes influencing coat colour pathways were amplified in eight animals (two per breed). Sequence comparison revealed 48 SNPs and three INDEL (INsertion DELetion). No breed-specific alleles were detected; however, several SNPs showed an uneven frequency distribution between breeds. In BIO, the genotype frequency distribution of a non-synonymous SNP suggested a possible role of TYRP1 in brown eumelanic goat coat colour. A total of 29 independent SNPs in 20 genes were selected and used to allocate 159 minimally related goat samples using STRUCTURE 2.2 and GeneClass 2 software. STRUCTURE 2.2 assigns 99% of individuals to the correct breed considering the prior information on putative breed of origin for each sample and 81% using only the genotypic data. The three algorithms available in GeneClass 2 performed with nearly equal efficiency, with 86% and 87% correct allocations. All the methods yielded an average probability of assignment >0.92 and a specificity index >0.86. Despite their coat colour variability, individuals belonging to ORO were fully assigned, showing that, in the absence of a breed-specific allele tied to coat colour, the best assignment resulted for the most genetically distinct breed. The lowest rate of correct assignment was observed in Verzaschese (73%), not ascertained in the breed panel used in the SNP discovery phase.

In June 2009, a white rough-toothed dolphin (Steno bredanensis) calf was photographed in a group of at least 50 dolphins in the southern Gulf of Guinea, 95 nauticol miles off the Gabon coast (01°45′S 007°29′E), West Africa. Reports of unusually pigmented cetaceans are infrequent and this record represents the first of an all-white rough-toothed dolphin. Furthermore, there is little documentation concerning rough-toothed dolphins and this note contributes to the knowledge of this species in tropical West African waters.

The purpose of this study was to develop and compare two methods for measurement of red-area coverage in white-red ornamental (koi) carp. One progeny produced by crossing two white-red koi breeders was analyzed. Among 49 fish in the progeny, 7 fish (14.3%) were solid white, 36 fish (73.5%) were white-red, and 6 fish (12.2%) were solid red. The red-area coverage in all white-red fish was determined by analysis of digital photographs using the image editing software Adobe® PhotoDeluxe® Business Edition (method I) and the specialized image analysis software Image-Pro® Plus (method II). The red-area coverage in white-red fish was highly variable, from 0.08 to 68.4%. The difference in red-area coverage for individual fish when comparing these two methods varied from 0.04 to 2.75% with a mean value of 1.03 ± 0.82% (SD). Class distributions of white-red fish with regard to red-area coverage determined by methods I and II did not differ significantly. The obtained data show that both methods can be successfully used for quantitative measurement of color patches in koi. Analysis of frequency distribution of red-area coverage in all fish (including solid white and solid red) showed that fish were clearly divided into two groups with regard to background color: fish with white background (which includes solid white and white-red fish), and solid red fish. The present study confirms that measuring the relative red body coverage gives a valuable insight into the quantitative description of color variability in koi and provides further information for the better understanding of inheritance of this trait. The development and application of new advanced methods for measurement of red-area coverage may stimulate further studies on this subject.

Paragangliomas are uncommon and those arising from the vagal trunk are rarer. Pigmented extra-adrenal paragangliomas are still rarer and reported sites of occurrence are the uterus, spine, retroperitoneum, bladder, mediastinum and orbit. The presence of abundant pigment in a cervical paraganglion has not been reported previously. We report one such unusual case of pigmented vagal paraganglioma that arose from the vagal trunk below the nodose ganglion, had massive central necrosis and showed hypovascularity on angiography. The unusual features and difficulties in the diagnosis of such cases are discussed.

Photoinhibition of photosynthesis in the red alga Chondrus crispus from different shore levels was investigated under laboratory and field conditions. The underwater light climate at Roscoff (French Atlantic coast), characterized by transmittance spectra, was shown to be intermediate between Jerlov coastal type 1 and oceanic type III. Chondrus crispus thalli were collected at four depths (3·5–8·5 m below high tide level) and exposed to daily courses of artificial and natural light. Filters were used to discriminate between the effects of photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) under the photoinhibitory treatments. In the presence of natural UVR, photoinhibition at midday was increased by up to 60%. Recovery from photoinhibition was measured at different times throughout the light stress. Recovery kinetics differed between morning and early afternoon in all treatments, and were dependent on the light dose. Whereas biphasic kinetics were observed in all treatments in the morning, the recovery in early afternoon was significantly slower. The influence of UVR on recovery was apparent after exposure to higher light doses. In all investigations, sensitivity to photoinhibition corresponded to zonation of the algae, with deeper-growing algae showing a greater depression of fluorescence yield, and slower recovery (indicating acclimation to the growth irradiance). An increase in the phycoerythrin content and increasing photosynthetic efficiency with increasing growth depth were observed.

The dynamics of astaxanthin and canthaxanthin were studied through an 11-month feeding experiment by following carotenoid deposition in male and female rainbow trout muscle, during and after spawning. Carotenoids were analysed by chromatography (HPLC), muscle colour was measured by a colourimeter and visual rank evaluation. In both sexes, a decrease in the muscle carotenoid content was observed at spawning time. The recovery of the muscle pigmentation differed between females and males, but seemed not to be influenced by the type of carotenoid additives in feed. The carotenoid content of the female muscle increased rapidly after spawing, while in the male this increase was slower. Eighteen weeks after spawing, carotenoid concentrations in the muscle of females corresponded to those before spawning, while in males they reached only one third of that amount. Significant correlations were found between chemical analysis, colourimetric measurements and visual rank evaluation.

A pigmented lesion of the soft palate was excised to exclude melanoma. The histology suggested an amalgam tattoo which was confirmed on energy dispersive X-ray analysis by the detection of silver and copper. This represents a very rare mimic of melanoma of the soft palate.