Effects of various levels of Spirulina on growth performance and pigmentation in goldfish (Carassius aurarus)

The study was conducted to determine the optimum level of dried Spirulina in test diets for goldfish. The goldfish fed the test diet supplemented with dried Spirulina at a concentration of 1, 3 and 5% compared to the control diet without Spirulina. The color value (L, a and b) was measured by a colorsmeter after 6 weeks of feeding trial. The L value in the goldfish fed control diet was highest when compared to those fed all Spirulina supplemented diets. The a values in the goldfish fed control, 1, 3 and 5% Spirulina were 11.70, 18.87, 20.30 and 23.68, and the b values in the goldfish fed control, 1, 3 and 5% Spirulina were 18.36, 28.86, 31.74 and 35.53 respectively. Growth performance was highest in the goldfish fed test diet containing 3% dried Spirulina (p<0.05). The results showed the positive effect of 3-5% dried Spirulina for pigmentation in goldfish; however, the test diet supplemented with 3% Spirulina resulted in the highest growth performance in goldfish.