Īlthough the list below is sorted by common name, in a number of cases, the common name is applied to different species. Ichthyologists debate the function of the adipose fin, doubting its role in swimming due to its small size and lack of stiffening rays or spines. While this adipose fin is generally considered the distinguishing feature, some tetras (such as the emperor tetras, Nematobrycon palmeri) lack this appendage. Artificial Plants add a unique, natural ocean feel while giving your fish a place to hide which reduces fish stress. This adipose fin represents the fourth unpaired fin on the fish (the four unpaired fins are the caudal fin, dorsal fin, anal fin, and adipose fin), lending to the name tetra, which is Greek for four. A new tank can be life-threatening, so the more mature the tank is, the better. Additionally, tetras possess a long anal fin stretching from a position just posterior of the dorsal fin and ending on the ventral caudal peduncle, and a small, fleshy adipose fin located dorsally between the dorsal and caudal fins. You should never add Neon Tetra fish to a tank that has not been properly cycled. They ordinarily possess a homocercal caudal fin (a twin-lobed, or forked, tail fin whose upper and lower lobes are of equal size) and a tall dorsal fin characterized by a short connection to the fish's body. Tetras generally have compressed (sometimes deep), fusiform bodies and are typically identifiable by their fins. For example, payara ( Hydrolycus scomberoides) is occasionally known as the ' sabretooth tetra' or 'vampire tetra'. Even vastly different fish may be called tetras. It is short for Tetragonopterus, a genus name formerly applied to many of these fish, which is Greek for 'square-finned' (literally, four-sided-wing).īecause of the popularity of tetras in the fishkeeping hobby, many unrelated fish are commonly known as tetras, including species from different families. Tetra is no longer a taxonomic, phylogenetic term. Consequently, they are extremely popular for home aquaria. Many of these, such as the neon tetra ( Paracheirodon innesi), are brightly colored and easy to keep in captivity. The Characidae are distinguished from other fish by the presence of a small adipose fin between the dorsal and caudal fins. Tetras come from Africa, Central America, and South America, belonging to the biological family Characidae and to its former subfamilies Alestidae (the 'African tetras') and Lebiasinidae. Tetra is the common name of many small freshwater characiform fishes.

Tetra fish tank