Werner's Killifish

About

Werner's Killifish (Aplocheilus werneri) is a surface-oriented predator from the island of Sri Lanka, where it lives in shallow, slow-moving streams and rivulets with heavy overhead shade and soft, silty bottoms. Like other members of its genus, it has the classic panchax body plan. Long, flattened on top, with a mouth angled upward for snagging prey at the water's surface. In the wild it picks off insects and small fry, so in captivity you'll want to feed a varied carnivore diet with plenty of live or frozen invertebrates. Unlike many killifish that hobbyists encounter, this species is not seasonal, meaning it doesn't follow an annual cycle tied to drying ephemeral pools. That makes it somewhat more straightforward to keep and breed than its annual relatives. It's generally considered manageable for a keeper with some experience, though its predatory instincts mean small tankmates are at risk. A tight-fitting lid is essential, as surface-dwelling killifish are notorious jumpers. Because it comes from shaded, slow streams, it tends to appreciate a well-planted setup with subdued lighting and gentle filtration that won't create strong currents.