Analysis of Skin Color Development in Live Goldfish Using a Color Machine Vision System

A color machine vision system (CMVS) was used to measure and quantify color development in the skin of live goldfish Carassius auratus raised in pond or well water and fed rations of different commercial feeds. Goldfish were of the ornamental Red Oranda variety, 3 months of age, 0.15 ± 0.01 g (mean ± SD) in body weight and 1.38 ± 0.22 cm in total length. Data on color development were acquired through a charge-coupled display color video camera and an image capture card attached to a personal laptop computer. We used a color analysis program developed at the University of Florida, Department of Food Science and Human Nutrition, to interpret the skin color patterns. Pixels from the computerized image were compared and matched to one of 64 color blocks (standards) representing the entire color spectrum. Pixel groupings were represented and recorded as a frequency (percentage) of occurrence for each color standard. The CMVS provided an objective method for measuring the skin color of goldfish and allowed safe sampling of live fish immersed in water, obviating the need for anesthesia. The CMVS can efficiently analyze skin color development in goldfish and has potential application as a way of objectively measuring the skin color of other live ornamental fish species.