Tetra a tall dorsal fin characterized by a short connection to the fish’s body. Additionally, tetras possess a long anal fin stretching from a position just posterior of the dorsal fin and ending on the ventral caudal peduncle, and a small, fleshy adipose fin located dorsally between the dorsal and caudal fins. This adipose fin represents the fourth unpaired fin on the fish (the four unpaired fins are the caudal fin, dorsal fin, anal fin, and adipose fin), lending to the name tetra, which is Greek for four. While this adipose fin is generally considered the distinguishing feature, some tetras (such
Yunnanilus macrogaster a short lateral line which has 6–10 pores and a line of pores on the head. The caudal peduncle is around 1.4 times as long as it is deep and its eyes have a diameter of slightly less than one fifth of the head length. It grows to a standard length of 63.2 mm. The body is yellowish with an irregular pattern of brown spots on its back and flanks with the dorsal surface of the head being darker and there is a dark patch on the operculum to the rear of the eye. The fins are hyaline and the