In 2003, a study redescribed several naturally occurring color varieties of S. formosus into four separate species.

[2] The majority of researchers dispute these redescriptions, arguing that the published data are insufficient to justify recognizing more than one Southeast Asian species of Scleropages and that divergent haplotypes used to distinguish the color strains into isolated species were found within a single color strain, contradicting the findings.

The morphological similarity of all seven species shows that little evolutionary change has taken place recently for these ancient fish.

The genus had a much wider distribution during the early Cenozoic, with fossil remains known from the Paleocene of Niger and Belgium,[5] and from the Eocene of China.

[6][7] There are currently 4 recognized species in this genus: Phylogeny based on the work of Pouyaud, Sudarto & Teugels 2003.