Midas Cichlid

• The populations of the Nicaraguan crater lakes, isolated only a few thousand years ago, are giving rise to new species within the same lake, and are one of the best-documented examples of speciation without geographical barriers.
• Gold and grey individuals coexist in the same population: the gold colour appears during the fish's life, when it loses its dark pigment cells.
• It is one of the parents of the aquarium blood parrot cichlid, an artificial hybrid.
• Its name, Midas cichlid, comes from its colour: many adults lose their dark pigmentation and turn an intense golden orange, although the normal form is brown and blotched. The two coexist in the same population.
• Adult males develop a fatty hump on the forehead, larger the better their condition, which works as a signal in the contest for territory.
• It is a cichlid with intense biparental care: the pair defend the clutch and the fry aggressively against much larger fish.
• The Nicaraguan crater lakes where it lives are a classic model for the study of speciation: closely related species have arisen in them in very little evolutionary time, a repeated case of radiation in enclosed waters.
• It has established itself as an invader in several countries outside its range, almost always through aquarium releases.

Skeleton type

Vertebrate - internal bony skeleton (bony fish)

Habitat and environment

Lakes and crater lagoons of Nicaragua and Costa Rica

Sources consulted: Wikipedia (es): Amphilophus citrinellus