Formosania

Formosania is a genus of freshwater fishes in the order Cypriniformes, commonly referred to as loaches. In most modern classifications it is placed in the family Nemacheilidae, the stone loaches, though its relationships within the broader group Cobitoidea have been refined as molecular data have become available. The genus is native to East Asia, with a distribution that centers on Taiwan and adjacent parts of mainland China.

Species are small to medium-sized, with elongated bodies, a subterminal mouth with barbels, and a tapered caudal peduncle. They are adapted to fast-flowing streams and rivers and often have flattened heads and dorsally positioned fins that aid stability over rough substrates. Coloration is generally muted, with patterns that provide camouflage among rocks and gravel.

Ecology and behavior: They typically inhabit rocky or gravelly substrates in clear, well-oxygenated waters. Diet consists of algae, diatoms, microinvertebrates, and detritus. Many forms are secretive, seeking cover under stones and within crevices; some species are primarily nocturnal.

Taxonomy and conservation: The genus has undergone revisions, with some species reassigned from or to Formosania as new data emerged. Habitat disruption, siltation, pollution, and water extraction threaten many populations, which are often restricted to small, isolated streams. As a result, several Formosania taxa are considered conservation priorities in regional assessments.