Scleromystax

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.

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

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 5 recognized species in this genus:

• Scleromystax barbatus (Quoy & Gaimard, 1824)
• Scleromystax macropterus (Regan, 1913)
• Scleromystax prionotos (Nijssen & Isbrücker, 1980)
• Scleromystax reisi M. R. Britto, Fukakusa & L. R. Malabarba, 2016 ^[3]
• Scleromystax salmacis M. R. Britto & R. E. dos Reis, 2005