Scleromystax

Scleromystax
Scleromystax barbatus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Siluriformes
Family:	Callichthyidae
Subfamily:	Corydoradinae
Genus:	Scleromystax Günther, 1864
Type species
Callichthys barbatus Quoy & Gaimard, 1824

Scleromystax is a genus of fish in the family Callichthyidae endemic to small tributaries from several coastal river basins draining the southern and southeastern regions in Brazil. ^[1] Most of the species of Scleromystax are highly sexually dimorphic; males have developed odontodes inserted in fleshy papillae on the preopercular-opercular region and the dorsal and pectoral fins are 2–3 times as long as those of females. ^[1] S. salmacis is an exception, as its sexually dimorphic features are subtle and non-remarkable.

Taxonomy

The species of Scleromystax were previously classified within the genus Corydoras . However, Scleromystax species are now thought to be more closely related to Aspidoras in a tribe called Aspidoradini. ^[2] Although the monophyly of Scleromystax has been demonstrated, phylogenetic relationships of its species remains obscure. In addition, the taxonomic status of its species are only partially resolved. ^[1]

Species

There are currently 7 recognized species in this genus: ^[3]

• Scleromystax barbatus (Quoy & Gaimard, 1824)
• Scleromystax lacerdai (Hieronimus, 1995)
• Scleromystax macropterus (Regan, 1913)
• Scleromystax prionotos (Nijssen & Isbrücker, 1980)
• Scleromystax reisi M. R. Britto, Fukakusa & L. R. Malabarba, 2016 ^[4]
• Scleromystax salmacis M. R. Britto & R. E. dos Reis, 2005
• Scleromystax virgulatus (Nijssen & Isbrücker, 1980)

References

1. Britto, M.R. & Reis, R.E. (2005): A new Scleromystax species (Siluriformes: Callichthyidae) from coastal rivers of Southern Brazil. Neotropical Ichthyology, 3 (4): 481–488.
2. Britto, M.R. (2003): Phylogeny of the subfamily Corydoradinae Hoedeman, 1952 (Siluriformes: Callichthyidae), with a definition of its genera. Archived 2007-09-28 at the Wayback Machine Proceedings of the Academy of Natural Sciences of Philadelphia, 153 (1): 119–154.
3. Fricke, Ron; Eschmeyer, William N. & van der Laan, Richard (eds.). "Species in the genus Scleromystax". Catalog of Fishes . California Academy of Sciences . Retrieved 17 September 2025.
4. Britto, M.R.; Fukakusa, C.K.; Malabarba, L.R. (2016). "New species of Scleromystax Günther, 1864 (Siluriformes: Callichthyidae) - extending the meridional distribution of genera endemic to the Atlantic Forest". Neotropical Ichthyology. 14 (3) e150158. doi:10.1590/1982-0224-20150158.