Gaussian software free skin#

Moreover, a relationship between melanin-based color morphs and stress response has been described in rainbow trout 14 and Atlantic salmon 12, while genetic correlations between skin pigmentation and growth have also been documented in rainbow trout 15. Furthermore, are related to health status, since intra-specifically divergent melanin-based color morphs have been related to differential exposure to parasites, and, once infected, to differential abilities to cope with the infection 12, 13. On the contrary, the area of skin covered by the melanosomes, i.e., whether melanin is aggregated or dispersed within the cell, is highly variable 1, 3, 4.Ĭhanges in melanin concentration and melanosomes’ mobility are also observed following exposure of fish to environmental, social and husbandry (in the case of reared fish) acute or chronic stressful stimuli. The number of melanophores is considered to be more or less stable, with only slight changes after exposure to environmental factors 3. Changes in skin lightness are closely related to the melanin content and the number and shape of melanophores 3. In aquaculture conditions, skin coloration, and especially lightness, has been related to product quality, animal welfare 2, 7, as well as to consumer’s perception and economic value of marketable-sized fish 8, 9, 10, 11. Such rapid changes are due to changes in the mobility (aggregation or dispersion) of the melanosomes within the melanophore and are termed physiological color changes 1, 3, 4, 5, 6. Lower vertebrates, including fish, can rapidly alter skin lightness depending on various factors, including background color, light intensity, ambient temperature, social context and husbandry practices 1, 4. Melanophores, in particular, consists of relatively large melanosomes that contain the light-absorbing pigment melanin, producing dark skin colors.

Chromatophores can be classified into two main categories: (1) the light-absorbing, melanophores, erythrophores, xanthophores and cyanophores, and (2) the light-reflecting, leucophores and iridophores 3. Lightness (brightness), hue and chroma sophisticated properties of fish skin are based on the presence, density, distribution and mobility of pigment cells (chromatophores) and the concentration of associated chemical compounds (pigments). In this context, we demonstrate that the proposed methodology may increase substantially the precision, as well as, simplify and expedite the relevant procedures for the quantification of melanin content in marine organisms.Ĭoloration patterns and skin morphological and physiological changes play a crucial role in the biology, physiology, behavior and ecology of fish 1, 2. Furthermore, convolutional neural network-based algorithms have been trained using the recorded data towards the classification of different scales’ samples with high accuracy. The hybrid images are automatically processed through optimized algorithms, aiming at the accurate and rapid extraction of various melanin accumulation indices in large datasets (i.e., total melanin content, melanophores’ area, density and coverage) corresponding to different fish species and groups. Here we present the application of a novel hybrid confocal fluorescence and photoacoustic microscopy prototype for the label-free imaging and quantification of melanin in fish scales samples with high spatial resolution, sensitivity and detection specificity. Nevertheless, the accurate quantification of melanin content or melanophore coverage in fish skin is quite challenging as a result of the laborious chemical analysis and the typical application of simple optical imaging methods, requiring also to euthanize the fish in order to obtain large skin samples for relevant investigations. Within this framework, the determination of skin chromaticity parameters in fish species is estimated either in specific areas using colorimeters or at the whole animal level using image processing and analysis software. Lower vertebrates, including fish, can rapidly alter skin lightness through changes in melanin concentration and melanosomes’ mobility according to various factors, which include background color, light intensity, ambient temperature, social context, husbandry practices and acute or chronic stressful stimuli.

Gaussian software free