Colouration in amphibians as a reflection of nutritional status : the case of tree frogs in Costa Rica

Colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. However, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. This study evaluated how body score and blood values interact with colouration in free-range Agalychnis callidryas and Agalychnis annae males. We found significant associations between body condition and plasmatic proteins and haematocrit, as well as between body condition and colour values from the chromaticity diagram. We also demonstrated that there is a significant relation between the glucose and plasmatic protein values that were reflected in the ventral colours of the animals, and haematocrit inversely affected most of those colour values. Significant differences were found between species as well as between populations of A. callidryas, suggesting that despite colour variation, there are also biochemical differences within animals from the same species located in different regions. These data provide information on underlying factors for colouration of male tree frogs in nature, provide insights about the dynamics of several nutrients in the amphibian model and how this could affect the reproductive output of the animals

Racial Awareness, Preference and Self-Identification in Negro and Caucasian Early Elementary School Children (Grades Kindergarten, One and Three)

Pictures of three identical faces differing only in skin colour were shown to 88 Negro and Caucasian subjects in grades kindergarten, one and three and questions about the pictures were asked. The procedure was designed to measure racial preference, awareness and self-identification and social awareness on the part of the subjects. Male subjects saw pictures of male faces and female subjects saw female faces. An experimental group of approximately one-half of the subjects saw a fourth picture face, which represented a novel stimulus and which was included to probe the reaction of the subjects to novelty. In addition, a warm-up task of size-brightness discrimination was administered to all subjects, in an effort to compare those children who exhibited a strong preference for size or brightness or those who showed the ability to see both dimensions equally well, on the subsequent racial and social attitude measures. Results showed few differences either between subjects of each race or among subjects within each race. Supporting an historical trend in the literature, both races in the present study were ethnocentric in their preferences—i.e. blacks and whites alike preferred their own race picture. There were no significant differences between size-brightness preferrers and non-preferrers on the racial and social awareness measures. All subjects were quite aware of racial labels and were able to properly apply them to appropriate faces; they were also accurate on the self-identification measure. Results in respect to the social awareness measure revealed no significant differences among the present subjects. These results led the investigator to suggest development of a more detailed and direct means of measuring social awareness. It was suggested that the study of racial awareness and attitudes is an important area of research and questions for future investigation were presented

Breeding programs for indigenous chicken in Ethiopia : analysis of diversity in production systems and chicken populations

The aim of this research was to generate information required to establish a sustainable breeding program for improving the productivity of locally adapted chickens to enhance the livelihood of rural farmers in Ethiopia. The first step was to characterize village poultry production environments and farmers’ objectives for keeping chickens, and to identify factors affecting the choice of genetic stock used in villages. This was achieved by carrying out a questionnaire survey and a participatory group discussion with village farmers in different geographic regions of Ethiopia. The low input nature of village environments, the prevalence of disease and predators, and other factors such as the use of chickens both as sources of eggs and meat, and income determined the choice of chicken breed used by farmers, and thus, should be considered carefully before initiating new breeding programs. The highest importance attached to adaptation traits and the existence of particular preferences for chickens of certain plumage colours and comb shapes were also found to have effects on developing new breeds for village systems. The next part of the thesis focused on identifying important and unique gene pools in local populations. This was achieved by characterizing the local chicken ecotypes both morphologically and molecular genetically. This way the genetic difference between the local populations and the level of genetic diversity within the populations was determined. Attributes important in breeding for tropical conditions such as the pea comb gene, and the naked neck gene have been identified. It was also revealed that the variability found within a single population could explain most of the genetic diversity (97%) in Ethiopian chicken populations. The result of this work is important both from conservation and utilization perspective and assists in maintaining indigenous genetic diversity for current and future generations. Finally, the pedigreed Horro population that was kept on station was used for estimating genetic parameters for the production traits, monthly and cumulative part period egg numbers and growth to 16 weeks of age. Because the pedigreed population was established only recently, data of only 2 generations were available for estimating these genetic parameters. The results are promising but inaccurate due to insufficient amount of data. They would need to be re-estimated when more generations have been produced and thus more data has been generated. <br/

Morphological features of indigenous chicken populations of Ethiopia

This study describes the variations in the physical features and the useful attributes of different populations of indigenous chickens. Five populations of chickens in different regions of Ethiopia were studied based on 13 qualitative traits recorded for a total of 1 125 chickens. Additional measurements on quantitative traits (shank length and body weight) were also included. Descriptive statistics (nonparametric and F tests) were used to analyze the data. Each of the study populations possessed multiple variants of plumage colours and other physical features. However, white body plumage is one of the prominent features of Farta chickens and red is predominant in the other populations. Pea comb is the dominant comb type in all regions. Most of the chickens in the high altitude regions have yellow skin. The geographic distribution and frequency of naked neck chickens are generally small, and the available small proportion is found mainly in the low altitude regions. Males in all populations are heavier and taller than the females. Body weights range from 1 411 g (Konso) to 1 700 g (Horro) in adult males and from 1 011 g (Konso) to 1 517 g (Sheka) in females. Most of the morphological traits that were studied showed a very low level of associations with each other

Genetic Approaches To The Analysis of Body Colouration in Nile Tilapia (Oreochromis niloticus)

Body colouration in tilapia is an important trait affecting consumer preference. In the Nile tilapia (Oreochromis niloticus), there are three colour variants which are normal (wild type), red and blond. In some countries, the red variant is important and reaches higher prices in the market. However, one major problem regarding red tilapia culture is their body colouration which is often associated with blotching (mainly black but also red) which is undesirable for the consumer. The overall aim of this work was to expand knowledge on various aspects of body colouration in Nile tilapia using genetic approaches. The results of this research are presented as four different manuscripts. The manuscripts (here referred as Papers) have either been published (Paper IV) or are to be submitted (Paper I, II and III) in relevant peer reviewed journals. Paper I and II investigated the inheritance of black blotching and other body colour components of the red body colour. Specifically, Paper I consisted of two preliminary trials (Trial 1 and 2), to look at the ontogeny of black blotching and body colour components over a period of six months. Trial 1 investigated the effect of tank background colour (light vs dark) on black blotching and other body colour components and was carried out using a fully inbred (all female) clonal red line. Trial 2 was carried out using mixed sex fish and was aimed to investigate the association of black blotching with the sex of the fish. The results from this study were used to guide the experiment described in Paper II. Sixteen red sires with various levels of black and red blotching were crossed to clonal females and the inheritance of blotching and other body colour components were investigated using parent-offspring regressions. The results showed no significant heritability for black blotching and body redness, but a significant correlation for body redness and black blotching was found in female offspring at one sampling point suggesting that attempts to increase body redness may increase black blotching, as had been hypothesized. Paper III was divided into two parts. The first objective was to map the blond locus onto the tilapia linkage map and the second was to investigate the interaction of the blond and red genes on black blotching using the blond-linked markers to distinguish different blond genotypes in heterozygous red fish (i.e. RrBlbl or Rrblbl). In the blond fish, the formation of melanin is almost blocked via much reduced melanophores and this feature may be able to help reducing the black blotching in red tilapia. Two intraspecific families (O. niloticus) and one interspecific family (O. aureus and O. niloticus) were used as mapping families and the blond locus was located in LG5. Four out of eight markers were successfully used to assess the interaction of blond on red blotched fish. The blond gene did not significantly reduce the area of blotching but did reduce the saturation (paler blotching) and enhanced the redness of body colour in the Rrblbl fish compared to the RrBlbl group. Finally, Paper IV aimed to find out the effect of male colouration on reproductive success in Nile tilapia. A choice of one wild type male and one red male was presented to red or wild type females and these fish were allowed to spawn under semi-natural spawning conditions. Eggs were collected from the female’s mouth after spawning and paternity was assessed using microsatellite genotyping and phenotype scoring. No significant departures from equal mating success were observed between the red and wild type males, however there was a significant difference between the red and wild type females in the frequency of secondary paternal contribution to egg batches. The results suggest that mating success of wild type and red tilapia is approximately equal. The results from this research help to broaden our knowledge and understanding on the aspects of body colouration in Nile tilapia and provide fundamental information for further research

The Effect of Fabrics and Designs on the Physical Comfort of Children Clothes in the Accra Metropolis

Safety and comfort are considered as top priority when selecting fabrics for manufacturing children’s apparels. Delicate skin of children reacts to certain fabrics which make them less comfortable to wear. The study aimed at examining the effects of fabrics and designs on the physical comfort of children clothes. The study adopted a descriptive study design. A total of 100 respondents, 30 fashion designers and 70 parents and guardians, were sampled for the study. Simple random sampling was used for the fashion designers, whereas accidental sampling was used for the parents and guardians. Descriptive statistics such as frequencies and percentages were used to analyse the data. Crosstabulations were also used to examine the relationship between variables. The study found that more parents considered the appearance of their children before other factors such as safety and comfortability. However, majority preferred cotton fabrics to be used for their children’s apparels. A majority of the fashion designers did not know that children’s skin reacts to certain fabrics. The main factors considered by the fashion designers in the selection of fabrics for constructing children’s apparels were colour, design, and purpose of apparels. The majority of the fashion designers adopted a number of safety measures, such as linen of apparel, light-weighted zippers and use of few buttons, to enhance the comfortability of children’s apparel. The study recommends that the NVTI, and the Ghana Fashion Designers Association should educate fashion designers on the reaction of children’s skin to fabrics from certain sources. The NVTI in collaboration with the Fashion Designers Association of Ghana should sensitise or train fashion designers on safety measures in apparel making through improved finishes. Keywords: fabrics, designs, safety, comfort, children, clothes, apparel