Anostomus anostomus

The Anostomus anostomus Headstander is an active and distinctive freshwater species known for its angled “head-down” swimming posture and bold horizontal striping. Native to South American river systems, these fish thrive in spacious aquariums of at least 55 gallons with strong filtration, moderate current, and plenty of open swimming space combined with driftwood, rocks, and hardy plants. They prefer warm, slightly acidic to neutral water conditions around 75–82°F and benefit from stable water quality. Headstanders are primarily herbivorous omnivores, requiring a varied diet that includes algae-based foods, spirulina flakes, fresh vegetables, and occasional protein-rich frozen or live foods. While generally peaceful, they can become territorial or fin-nippy toward similar-shaped fish, so they are best housed with robust community species. Their energetic behavior, unusual swimming style, and striking appearance make them a fascinating centerpiece for larger South American aquarium setups.