Aquarium favorites include GOLDFISH (8 letters), Angelfish (9 letters), Rasbora (7 letters), PENGUIN (7 letters), Tetra (5 letters), Tetras (6 letters), Aerator (7 letters), and TANK (4 letters). GOLDFISH are a popular choice for aquariums due to their bright colors and ease of care. Angelfish are also popular due to their unique shape and coloration. Rasbora are small schooling fish that can add movement and color to an aquarium. Penguins are small, peaceful fish that are easy to care for. Tetras are small, colorful fish that are often kept in groups. Tetras come in a variety of colors and sizes. An aerator is a device used to increase oxygen levels in an aquarium. Tanks are the containers that hold the water and fish in an aquarium. Guppies are small, colorful fish that are easy to care for and breed.