Order Tetraodontiformes
Suborder Tetraodontidei
Family Tetraodontidae
Genus Colomesus
— South American Puffer, Amazon Puffer, Brazilian Puffer — Colomesus asellus [Muller & Troschel, 1849]. Synonym: Cheilichthys asellus. South America, river basins of the Amazon, Guapore, Essequibo, Orinoco in Brazil and Peru. Length up to 14 cm, in aquarium up to 9 cm. It has broader stripes than Colomesus psittacus, and a ring-shaped black spot on the caudal peduncle, which is absent in its cousin. Yellowish or olive-colored on the upper side of the body with thick black partial vertical stripes.
The black spot is located on the lower side of the body at the base of the tail, the rest of the lower part is white. There are color variations in individual fish — it can be darker or lighter, more uniform in color, with less distinct stripes, and the coloration also changes depending on mood or stress.
Completely peaceful (both towards conspecifics and other species), small species, strictly freshwater. It is best kept in a species tank in groups of 3 or more, but can also be kept in a community aquarium with active swimming fish. Suitable tank mates include similarly-sized Characins, Rasboras, and peaceful smaller Cichlids; aggressive species, slow-moving fish, Angelfish, and Gouramis should not be added.
Despite its small size, it is very fond of swimming, so the aquarium should not be too cramped. Does not harm plants. Water should be soft to moderately hard; usually kept in fresh water, but can tolerate slightly brackish water. Very sensitive to dissolved oxygen deficiency.
Carnivorous species, readily accepts frozen foods in the aquarium (Gammarus, shrimp, bloodworms). This pufferfish species has the fastest-growing teeth, which must be trimmed 1 or 2 times a year. Therefore, snails must be included in the diet for wearing down teeth and preventing overgrowth.
If they are used for snail control, no other food should be given during that time. In nature, they spawn on flat stones. Do not add copper-containing preparations. Lifespan up to 10 years. pH 5.5-7.2; dH 5-15°; T 24-28°C.
— Banded Puffer — Colomesus psittacus [Bloch & Schneider, 1801]. Synonym: Tetrodon psittacus. Western Atlantic coast of South America from the Gulf of Paria to the mouth of the Amazon River in Brazil. Reaches up to 25 cm in length, in aquariums 10-15 cm.
Features a beautiful yellow-green camouflage pattern and an amusing face. There are 6 dark transverse stripes on the flanks, the first located between the eyes and the sixth at the base of the caudal fin. Light areas between the stripes can sometimes be shaded; the belly, including the lower part of the caudal peduncle, is unpigmented.
These are very aggressive fish; in a community aquarium, tank mates should be chosen from fairly large fish that swim in the mid-water. Can be kept singly or in small groups of 2 to 3 individuals in a sufficiently large tank. Substrate of fine sand, as the fish sometimes burrows. Can be kept in fresh water, but thrives wonderfully in a brackish aquarium.
Provide shelters made of stones, driftwood, and partially dense vegetation while leaving open swimming space. Considering their need for strong water current, a powerful filter should be installed. Diet — snails, earthworms, and mealworms. If underfed, they may nip bottom-dwelling fish, even large ones. Water soft pH 5.0-7.0; dH 2-8°; T 25-29°C.
Identification: Genus Colomesus — Colomesus.
Tetraodon biocellatus, Tetraodon cochinchinensis.
Carinotetraodon salivator, Carinotetraodon travancoricus. 
