Arirará

The striped pike 'characin', Boulengerella lateristriga, is a ctenoluciid from the rio Negro basin and parts of the upper Río Orinoco. It appears limited to black water rivers and tributaries, where the water is stained darkly with humic acids and the pH can be as low as 3.0 or 4.0. A thin dark stripe from the rear of the eye to the caudal peduncle and dark crossbars on the caudal-fin lobes separate it from the similar B. maculata. It grows to 258 mm SL.

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.