, or maybe the Siamese fighting fish is the most popular. These wonderful tiny tropical fish are great for small aquariums, and you'll find them in just about any pet store. The hatchetfish is a fascinating tropical fish that spends its everyday living up within the floor on the tank. https://sites.google.com/view/aquariumshoponline/how-to-maintain-a-2-feet-aquarium-bigger-fish-tanks