Three experiments were conducted to study the effect of adding xanthophyll on body color of Clarias fuscus. In experiment A, walking catfish were collected from natural river, common pond and concrete pond, representing wild, semicultured and cultured walking catfish. The xanthophyll content in skin and muscle of each group was 8.01, 4.64, 1.61 and 2.06, 1.83, 0.96 mg·kg-1 respectively. In experiment B, adult walking catfish, with an average weight of 52g, were divided into 4 groups and fed with artificial diet without (control) or with 100, 150, 200mg·kg-1 xanthophyll for 6 weeks. The xanthophyll content in skin and muscle of each group was 1.07, 5.88, 7.02, 7.81 and 0.64, 1.35, 1.81, 1.86 mg·kg-1 respectively. In experiment C, fingerling walking catfish,with an average weight of 3.2g, were divided into 4 groups and fed with artificial diet without (control) or with 50, 100, 150mg·kg-1 xanthophyll for 6 weeks. The xanthophyll content in skin and muscle of each group was 3.2,8.73,11.49,12.51 and 0.87,1.71,1.97,2.03 mg·kg-1 respectively. The results showed that the differences of body color between wild and cultured fishes come from the different xanthophyll content in diets, the addition of xanthophyll could improve body color of walking catfish and the feeding strategy for pigment was adding xanthophyll 100 mg·kg-1 in diet for adult walking catfish or xanthophyll 50 mg·kg-1 for fingerling.
本地胡子鲶是我国南方地区,特别是两广地区广泛养殖的一种鱼类,具有肉味鲜美、适应性强等优点.通常野生本地胡子鲶体色呈金黄、土黄、褐黄不等,但在人工养殖条件下其黄色逐渐褪去而变灰变黑,影响其商品价值.作者对野生与养殖本地胡子鲶体色及皮肤、肌肉叶黄素含量进行了比较,本试验旨在通过饲料中添加叶黄素类产品以改善养殖胡子鲶体色,提高其商品价值.
