Apistogramma viejita
Apistogramma viejita is a dwarf cichlid in the subfamily Cichlinae, in the tribe Geophagini. It is a benthopelagic freshwater fish that lives in the Meta River and the Orinoco River in Colombia. They grow up to 4.6 cm in standard length. The males gather harems for spawning if there is an excess number of females. The clutch of up to 100 eggs is deposited on the ceiling of a cave and is tended by the female parent. "Apistogramma macmasteri" is often mislabelled as "Apistogramma viejita" by shops. In fact the latter is a very rare fish which is  not commercially bred and thus is not commonly available in the trade. In the specific name, the author, Sven O. Kullander, is referencing the use of the Spanish word "vieja", meaning "old lady", for many species of cichlids in South America. The diminutive "viejita" is used for the smaller cichlids in eastern Colombia, although Kullander does not reveal why this is the case.