４蛋种鱼头钝 ,体短而肥 ,呈卵圆形 ,主要特征是绝大多数无背鳍 ,有成双的尾鳍和臀鳍。鳍的长、短和形状状差异较大。一般丹凤、翻鳃、红头等的鳍条较大 ;绒球、水泡、虎头等的鳍短小而圆 ,但个别的品种例外 ,如大尾虎头等 ,其尾鳍的长度往往超过体长。（１）红水泡 :眼具有水 4 egg species head blunt, short and fat body, was oval, the main feature is the vast majority of no dorsal fin, a pair of caudal fin and anal fin. Fins of the long, short and the shape of the larger differences. General Danfeng, flip gills, red head and other larger fin; pompon, blisters, tiger fin short and round, but the individual species exceptions, such as tailed tiger first, the length of the caudal fin tend to exceed body length. (1) red blisters: eyes with water