Comparison by image analysis of colour of meagre (argyrosomus regius asso, 1801) grown cage and earth ponds

The increasing demand for animal protein, interest in healthy and nutritious foods and the desire to meet these have enabled the increase and development of aquaculture. One of the species that contributes to the development of aquaculture is the meagre fish (Argyrosomus regius Asso, 1801). Depending on the nutrition, differences in both the appearance and meat quality of fish raised in different culture conditions may occur. Therefore, it is important to present data on the visual attributes of fish raised in different culture conditions. In this thesis study, it was aimed to determine the skin colour and dimensions of meagre fish, which has been started to be raised in sea cages and earthen ponds, by image analysis method. For this purpose, 66 meagre fish raised in earthen ponds and 53 fish raised in net cages were used. The photographs of the fish were taken with a digital camera on a light box. Image analysis was used for the length-weight, area-weight and visual attributes of the fish. While the weights of the fish raised in earthen ponds varied between 311.9-1142.1 g, the weights of the fish raised in net cages varied between 253.2 950.4 g. Length-weight data were calculated with the power equation Weight (W) = A (length L) B. The R2 value for cage and earthen pond fish varied between 0.850-0.990, respectively. According to the B value, granny fish reared in both reared conditions showed (2.848-2.951) showed a negative allometric growth. For the view area (V)-weight relationship, the power equation was used. R2 values varied between 0.890-0.995 for cage and earthen pond fish, respectively. Fish reared in earthen ponds weigh less than those reared in cages, according to the same view area. The L*, a* and b* values of granny fish reared in earthen ponds were found to be statistically significantly higher than those of fish reared in net cages (p<0.05). The average Delta E values of the differences between the right and left skin colors for net cage and earthen pond fishes were1.893, and 1.781, respectively. When the research group fish are evaluated individually, Delta E values greater than 3 indicate that there are noticeable color differences between both culture conditions. The average Hue values of cage fish were higher than those of earthen pond fish. There was no correlation between the color change index (CCI), the texture change index (TCI) and the grayscale energy and grayscale entropy values. However, TCI and CCI values were highly correlated.