The growth performance, nutrient utilization and skin pigmentation of goldfish, Carassius auratus fingerlings fed with a freshwater microalga, Haematococcus pluvialis supplemented diets were assessed in the study. Five experimental diets were formulated at different supplementation levels of H. pluvialis (0, 0.5, 1.0, 1.5 and 2.0)mg/100g in the control (T0), (T1), (T2), (T3) and (T4) respectively .C. auratus fingerlings (7.57 ± 0.02) g were stocked in ten (10) rectangular glass tanks with dimension 60cm by 40cm by 40cm for 56 days. Results showed that weight gain, FCR and SGR improved significantly (P>0.05) with increasing supplementation levels of H. pluvialis. The best supplementation level was recorded in Treatment 4. The histological study of the skin of C. auratus also revealed positive pigmentation influenced by H. pluvialis supplementation. Chromatophores and skin pigmentation improved with increasing supplementation levels of H. pluvialis. This study showed that H. pluvialiscan be used as a supplement to increase the growth performance and enhance skin pigmentation of goldfish C. auratus fingerlings.
