Tadu

Current knowledge suggests that H. formosanus is the most widely-distributed and following Chen and Fang (2009) it can be distinguished by the following suite of characters: 3+7 dorsal-fin rays; 10-12 pectoral-fin rays (modally 11) +9-11 (modally 10)...

This species occurs in a couple of colour forms with fish from northern and central Taiwan possessing a greyish base body colour and those from the Linbian river, southern Taiwan having a dark marking in the anterior portion of the first dorsal fin and larger, more intense red spots on the body. The latter form is also smaller in size, lays smaller eggs, does not exhibit extreme sexual dimorphism and has been refe...