Anostomids

Anostomids are a family of freshwater fish belonging to the order Characiformes. They are commonly known as anostomids or headstanders. These fish are native to South America, found in various river basins including the Amazon, Orinoco, and Paraná. A distinctive characteristic of anostomids is their tendency to swim in an upward-angled or headstanding position, which gives them their common name. This behavior is thought to be related to foraging for food on submerged surfaces or in the water column.

Anostomids are generally small to medium-sized fish, with most species ranging from a few centimeters to about 20 centimeters in length. They typically possess a moderately elongated body, a small mouth, and large eyes. Their coloration can vary widely depending on the species, often featuring patterns of stripes, spots, or solid colors, which can aid in camouflage. Their diet consists mainly of algae, aquatic vegetation, and small invertebrates.

The family Anostomidae includes several genera and a significant number of species. They are popular among aquarium hobbyists due to their interesting behavior and often attractive appearance. However, specific care requirements, such as water parameters and tank size, can differ between species, so research is recommended before keeping them. They are generally peaceful fish and can be kept in community aquariums with other compatible species, although some larger or more territorial individuals may require more space.