Perubahan Warna Ikan Maskoki Carassius auratus yang Diberi Pakan Berkarotenoid dengan Lama Pemberian Berbeda

Abstract

Goldfish or “maskoki” is a beautiful freshwater ornamental fish. Price of goldfish depends on several factors, one of them is the body color. The body color of goldfish depends on carotenoid contain on its feed. Carotenoid source must be added into the goldfish feed that used for intensive rearing. Unfortunately, the price of commercial feed that contain carotenoid such as spirulina, relatively more expensive than common commercial feed. So, it require a combination between common commercial feed and those which contain spirulina to lower the cost. Uniformed orange fish seeds, average body length 3.2 ± 0.28 cm and average weight 4.9 ± 0.9 gram fed common commercial feed and feed that contain spirulina as carotenoid source. Fish were fed three times a day with feeding rate 5% of its biomass on first 20 days of rearing and 4% on the next 20 days. Ratio feeding period of common feed : carotenoid feed in this research was: 1) 40:0 (fed common feed for 40 days and carotenoid feed for next 0 days), 2) 30:10, 3) 20:20, 4) 0:40. Percentage of color score evaluation was the total number of fish based on color criteria divided by total number of living fish times 100%. Color changing of goldfish that happened on application of feeding period with carotenoid feed for 40 days was orange-red as much as 93.10% and those which did not change orange color was 6.90%. Color changing that happened on application of feeding period with carotenoid feed for 20 days was orange-red as much as 58.33% and yellow-orange was 2.78% and those which did not change orange color was 38.89%. Color changing that happened on application of feeding period with carotenoid feed for 10 days was orange-red as many as 55% and faded 5% and those which did not change orange color was 40%. Color changing that happened on application of feeding period with carotenoid feed for 0 days was yellow-orange as many as 36.11% and faded 5.56% and those which did not change orange color was 58.33%. Carotenoid feed did not effect to weight and length growth rate and length differentiation coefficient. The best period of carotenoid feed for goldfish is 10 days that resulted color change to orange-red was 55% and best of R/C ratio.