Abstract:Histological characters of taste bud during early development of Mandarin Fish (Siniperca chuatsi) at 3﹣28 days were observed through the paraffin section and H.E staining, and further observation was made via scanning electron microscopy to analyze the types and density of taste buds at 28 days old. The results showed that the mouth was not open until 3 days old when the taste bud was undifferentiated (Fig. 1a); at 7 days old, the mouth was open, and taste bud was in oval shape with gentle projections, which were distributed in the mucosa epidermis of pharynx epithelium, tongue, jaw and gill arch (Fig. 1b, Fig. 2a﹣d); at 14 days old, lower jaw began to develop, and taste bud was conical, meanwhile, the protrusion height was increased, and the number of taste bud in pharynx, gill and tongue began to increase (Fig. 1c, Fig. 2e﹣h); at 21 days old, taste bud was in trapezoidal shape with obvious projections, the number of which has increased in jaw, pharynx and tongue, most notably in gill arch (Fig. 1d, Fig. 2i﹣j); at 28 days old, taste bud developed completely, and the number of taste bud increased in all oropharyngeal cavity (Fig. 2k). Three main types of taste buds were observed by scanning electron microscopy (Fig. 3): type Ⅰ taste bud was in ball-like shape with contained quantities of microvilli, its processes were higher than that in the mucosa epithelium, and taste pores bumped out; type Ⅱ taste bud contained a few microvilli, its processes slightly higher than that in the mucosa epithelial , and taste pore was concave beneath; type Ⅲ taste bud contained a few microvilli, its processes were almost coplanar with the mucosa epithelium and the smooth inner hole. The number of Type Ⅰ taste bud was maximal, and that of type Ⅱ was minimal in the jaw, pharynx, while a large amount of type Ⅰ taste bud was observed in the tongue which contained no type Ⅲ taste bud (Fig. 4, Table 1). The results showed that taste bud development in early stage played an essential role in feeding, and that type Ⅰ and Ⅱ taste buds were properly the main types in mechanical and chemical recognition during food intake.