Three spot gourami are endemic to the Mekong basin in Cambodia, Laos, Thailand and Vietnam and Yunnan in southeast Asia. These fish live in marshes, swamps, canals, and lowland wetlands. They migrate during the flood season from permanent water bodies to flooded areas, such as seasonally flooded forests in the middle and lower Mekong. During the dry season, they will return to these permanent water bodies. These fish feed on zoo plankton, crustaceans and insect larvae. The male builds a bubble nest for the eggs, which he protects aggressively.

Pterophyllum is a small genus of freshwater fish from the family Cichlidae known to most aquarists as “angelfish”. All Pterophyllum species originate from the Amazon River, Orinoco River and Essequibo River basins in tropical South America. The three species of Pterophyllum are unusually shaped for cichlids being greatly laterally compressed, with round bodies and elongated triangular dorsal and anal fins. This body shape allows them to hide among roots and plants, often on a vertical surface. Naturally occurring angelfish are frequently striped longitudinally, coloration which provides additional camouflage. Angelfish are ambush predators and prey on small fish and macro invertebrates. All Pterophyllum species form monogamous pairs. Eggs are generally laid on a submerged log or a flattened leaf. As is the case for other cichlids, brood care is highly developed.

Pimelodus pictus, also known as the pictus cat, is a small (11.0 centimeters (4.3 in) TL) member of the Pimelodidae family of catfishes, native to the Amazon and Orinoco river basins and commonly kept as a pet in freshwater aquariums. Pictus catare sometimes mislabeled as Angelicus cats in the aquarium trade, but the latter name actually refers to an unrelated African catfish, the mochokid Synodontis angelica.

The goldfish (Carassius auratus auratus) is a freshwater fish in the family Cyprinidae of order Cypriniformes. It was one of the earliest fish to be domesticated, and is one of the most commonly kept aquarium fish. A relatively small member of the carp family (which also includes the koi carp and the crucian carp), the goldfish is a domesticated version of a less-colorful carp (Carassius auratus) native to east Asia. It was first domesticated in China more than a thousand years ago, and several distinct breeds have since been developed. Goldfish breeds vary greatly in size, body shape, fin configuration and coloration (various combinations of white, yellow, orange, red, brown, and black are known).