Atractosteus

This is one of the largest freshwater fish species in the world, and clearly shouldn't be considered a home aquarium subject at all given its eventual size and the fact it can live for well in excess of 50 years. We include it here only because some public aquaria are able to maintain it long-term. Unfortunately, juveniles are seen for sale quite regularly in the aquari...

Endemic to Cuba where it's found throughout western parts of the island plus Isla de la Juventud (Isle of Youth, formerly known as the Isle of Pines). It's endangered across most of this range and captive breeding efforts are well-established. Known locally in Cuba as 'manjuari', it clearly shouldn't be considered a home aquarium subject...

Found in both Caribbean and Pacific-slope drainage basins in Central America, from southern Mexico through Belize, Guatemala, Honduras and Nicaragua, and into Costa Rica. This species clearly shouldn't be considered a home aquarium subject at all given its eventual size and the fact it can live for several decades.