Are you interested in the ornamental aquatic fish trade, how aquarium fish are caught in their native waters, and conservation?
Though filmed several years ago, Wild Caught: Aquarium Fish Trade of the Amazon is a wonderful two-part documentary about the Amazon River, conservation, and the fish trade. I highly encourage you to watch the two videos. They shed light on many issues facing the aquarium fish hobby. Clearly, the documentary does not focus specifically on cichlids, but fish from the Cichlidae family are part of the trade. There are numerous cichlid genera found in the waters of the Amazon and its tributaries, including pikes (Crenicichla), apistos (Apistogramma), eartheaters (Geophagus, Satanoperca), discus (Symphysodon), angelfish (Pterophyllum), and many others.
Another interesting resource for information about fish exports from the Amazonas region of Brazil in South America, though a bit more dated, is the journal article Analysis of the ornamental fish exports from the Amazon state, Brazil. There is a great table in the article listing the volume of numerous genera/species exported from the waters of Brazil.