Manacapuru

The Amazon puffer, Colomesus asellus, is a freshwater puffer found throughout much of the Amazon basin, with records north to Guyana and Venezuela. Also traded as the South American puffer or 'SAP', it is told from congeners by a transverse row of dermal flaps across the chin. It lives mostly in well-oxygenated river habitats, is intolerant of organic waste, and forms loose aggregations, so a group of 6 or more is best, away from the general community.

Metynnis lippincottianus is a spotted silver dollar from Brazil and French Guiana, found in the lower and middle Amazon and the Oyapock system. It is occasionally seen for sale, sometimes as 'silver dollar', and its spotted pattern tells it apart from M. argenteus and M. hypsauchen. The spots are less pronounced than in M. maculatus, with which it shares a common name. The precise extent of its range is unclear.

The sharphead eartheater, Satanoperca acuticeps, is a cichlid from the central Amazon basin in Brazil, including the lower rio Negro and rio Branco. Relatively rare in the trade, it is sometimes confused with S. daemon and S. lilith but has three dark flank blotches (vs. two in S. daemon, one in S. lilith). Unless breeding it is surprisingly peaceful, and it is very rarely bred in aquaria.

Satanoperca lilith is an eartheater cichlid known only from Brazil, where it is widely distributed along the Solimões/Amazon main channel. Despite that extensive range it is uncommon in the ornamental trade, where it is sometimes called 'one-spotted demon fish' or 'one spot eartheater'. A single dark blotch on the flank separates it from the closely similar S. daemon, which has two.

Brachyplatystoma capapretum is a large, piscivorous pimelodid catfish found throughout much of the Amazon basin, from near Belém to Iquitos in Peru. The largest recorded specimen measured 880 mm, and it is suitable only for public aquaria and a very small minority of private aquarists. It is very similar to B. filamentosum but smaller, with shorter maxillary barbels, a moderately forked caudal-fin with lobes of equal size, and adults very dark above.

The silver arowana, Osteoglossum bicirrhosum, is a large predator from the Amazon basin, plus river systems in Guyana and French Guiana. Reaching 80 cm, it is largely unsuitable for the home aquarium, and although juveniles are readily available, few private aquarists can house an adult long-term. Juveniles have a single dark lateral stripe, while in those of its only congener, O. ferreirai, most of the body and fins are dark.