Shark Minnow

About

The Shark Minnow (Luciosoma bleekeri) is a sleek, torpedo-shaped cyprinid from the river systems of mainland Southeast Asia, including the Chao Phraya, Meklong, and Mekong basins. In the wild it hugs the surface of flowing water, picking off insects that fall from the canopy and occasionally taking small crustaceans or fish. During flood season it pushes into inundated forests, retreating to permanent river channels as the waters drop in late November and December. Its common name references its silhouette rather than any true relationship to sharks, and the resemblance is convincing. A long, laterally compressed body with a forked, heavily spotted tail and a dark lateral stripe that breaks into interconnected blotches before ending in a bold black smudge at the upper caudal-fin lobe. Well-developed barbels are another useful identification feature. Buyers should be cautious at the shop, because Luciosoma species are frequently mislabeled, and several scientific names circulate incorrectly in the trade. L. bleekeri is best told apart from the similar L. setigerum by the absence of black spots on the lateral-line scales. Despite a beginner care rating, this species grows large and moves fast, so the tank needs to be genuinely spacious with room to swim at pace near the surface.