Veresugulus

Veresugulus is a monotypic genus of freshwater fish in the family Cyprinidae. The only described species is Veresugulus microphthalmus. The species was described by Nguyen and Park in 1998. The genus name Veresugulus is a neologism introduced with the original description and has not been used for other taxa.

Veresugulus microphthalmus is a small, slender fish reaching about 7 cm in standard length. Dorsal coloring is olive-brown with a silvery or pale ventral side. A distinctive feature is its very small eyes relative to body size, a trait reflected in the specific epithet microphthalmus. The body is laterally compressed with a shallow belly and a single dorsal fin.

Endemic to the upper Mekong River basin in Laos and Cambodia, it prefers clear, fast-flowing streams and riffles with rocky or gravel substrates at mid-elevations. It is rarely found in slower, silt-laden sections.

Veresugulus microphthalmus is omnivorous, feeding on periphyton, algae, and small invertebrates. It forms loose to moderately dense schools and shows seasonal reproduction with spawning in riffles during the rising water phase. Eggs adhere to gravel and sift through crevices as they develop.

IUCN lists the species as Vulnerable due to habitat modification from dam construction, deforestation, and sedimentation in the Mekong basin. Taxonomically, relationships within Cyprinidae are debated; molecular work has yet to resolve Veresugulus' closest relatives.

Origin of the genus name is tied to the original description; no familiar common names exist. The species has limited commercial significance but is of interest to researchers studying riverine fish diversity in Southeast Asia.