文昌鱼(Branchiostoma belcheri tsingtauense)属于脊索动物门(Chordata)头索动物亚门(Cephalochordata)文昌鱼科(Branchiostomidae),为国家二级保护动物。据认为(Carrol,1988),文昌鱼是和脊椎动物亲缘关系最近的现存无脊椎动物,在系统演化上,它介于无脊椎动物和脊椎动物之间,是研究脊椎动物起源的珍贵材料。此外,文昌鱼体内蛋白含量高达70％,并含有丰富的碘、铁和磷,脂肪含量低(Svetashev,et al.,1994),在我国福建省和 Branchiostoma belcheri tsingtauense belongs to the genus Branchiostomidae of the genus Chordata and belongs to the Cephalochordata family of secondary level protected animals. It is believed (Carrol, 1988) that amphioxus is an extant invertebrate that has the closest genetic relationship with vertebrates. In phylogenetic terms, it is between invertebrates and vertebrates and is a valuable material for studying the origin of vertebrates. In addition, amphioxus contains up to 70% protein in its body and is rich in iodine, iron and phosphorus with low fat content (Svetashev, et al., 1994)