The Order Atheriniformes consists of small to medium-sized ray-finned fishes, commonly known as silversides, rainbowfishes, and related species. They are mostly marine and freshwater, often found in coastal waters, estuaries, and rivers. Members of this order typically have elongated bodies, two dorsal fins (the first spiny and the second soft-rayed), and a silvery lateral stripe. Atheriniformes are generally planktivorous or omnivorous, feeding on small invertebrates and algae. They play an important role in aquatic ecosystems as prey for larger fish and birds, and some species are popular in aquaculture and the aquarium trade due to their bright colors and schooling behavior.