In the ponds of clean, transparent, still waters and luxuriant vegetation dwell exceptional creatures, our beloved Guajacones. They surprise us with their fights, games, courtships, loves and quietness, when they rest.While our eyes follow their thousand evolutions in the water, we receive the luminous, golden-green, purplish reflections sent by their iridescent scales. Blessed is he who has discovered them and adorns his fountains and fishbowls with them.This is the book of those nice little animals that adorn with their presence the Cuban aquariums. It deals with different themes related to these fish, with the aim that young researchers penetrate into their essence and discover their brilliance.