Freshwater Fishes of Costa Rica is the only decent book we can find on the non-marine fish of Costa Rica. It’s not new (it’s a 2002 reprint, this 2nd Ed published in 1998) but it is now in stock – I mention this because we have been waiting for it to come into stock for a year! This is a long wait… but well worth it. In Portuguese and English, Bussing has provided a high level of taxonomic, physiological and ecological information, there are good maps and diagrams, as well as some reasonable colour and black & white images. You may also be interested in the Check List of Fishes of South and Central America.
