Hemiods

Hemiods are a family of freshwater fish, specifically belonging to the order Characiformes, which also includes tetras and piranhas. They are native to South America, primarily found in the Amazon and Paraná river basins. The name "hemiod" is derived from the Greek words "hemi" meaning half and "odous" meaning tooth, referring to the reduced or absent incisors in their upper jaw.

These fish are generally small to medium-sized, with slender, elongated bodies. Their coloration can vary, often featuring silvery bodies with iridescent or metallic hues. They typically possess a single dorsal fin and a forked caudal fin. Hemiods are omnivorous, feeding on a diet of algae, detritus, small invertebrates, and plant matter. They are often found in schools, inhabiting clear to moderately turbid waters, frequently near the substrate.

In the aquarium trade, some species of hemiods are kept as ornamental fish due to their peaceful nature and attractive appearance. However, they are not as commonly encountered as some of their tetras relatives. Their specific ecological role in their native environments involves contributing to nutrient cycling and serving as a food source for larger predatory fish.