São Francisco

Leporellus vittatus is an anostomid with a huge natural range across the Amazon, Paraná-Paraguay, São Francisco and Orinoco river systems. Unlike most anostomids it is adapted to a benthic existence in flowing water and spends most of its time on or around the substrate. Occasionally exported, it requires quite specialised conditions, an aquarium of at least 210 by 60 cm and ideally a group of six or more.

The white piranha, Serrasalmus brandtii, may be restricted to the rio São Francisco watershed in eastern Brazil. Also known as 'green piranha' or 'Brandt's pirambeba', it appears infrequently in the trade, and its name is sometimes misapplied to the distantly related Pygopristis denticulata. Adults are uniformly golden-bronze with dark fin margins and a concave head profile above the eye. It is best kept alone as a single specimen.

L234, the dragon hi fin pleco, is a large Megalancistrus catfish known only from the rio São Francisco system in eastern Brazil. The L-number was previously applied to Megalancistrus parananus, but that species is native to the Paraná, Paraguay and Uruguay drainages, so L234 appears to be an unidentified species. It grows to 500 to 600 mm and can behave very aggressively in confined surroundings.

The piraya, Pygocentrus piraya, is a piranha restricted to the rio São Francisco watershed in eastern Brazil. It can be identified by bright yellow-orange pigmentation on the lower jaw, opercle and flanks in life, and larger specimens have rays in the adipose fin. It is best maintained alone because mature individuals are reported to be extremely aggressive towards one another when space is limited.