Tetras

Tetras
When compared with larger characins, such as the Pacu, the diminutive size of the smaller tetras illustrates the great range withing the family Characidae. Temperaments, likewise, vary in the extreme, from the tranquility of the Neon Tetra to the ferocity of the Piranha. Native to South America and Africa, all characins make decorative additions to the aquarium - there are about 1,200 species in the wild. They have teeth in their jaws, unlike cyprinids. Many carry an additional small adipose fin behind the dorsal fin, although this is not an exclusive feature of characins (some other genera have it too, e.g., Corydoras catfish). Many smaller tetras are readily bred in soft waters, but very often the eggs are light sensitive.