Figure 1.

Geographic distribution and morphological diversity of focal populations of Midas cichlid fish. The two great lakes Nicaragua and Managua are intermittently connected by Rio Tipitapa that flows through Tisma Pond. Las Canoas is not a crater lake, but a water reservoir, which had historically been connected to L. Nicaragua by Rio Malacatoya until the construction of a dam. All crater lakes are isolated bodies of water with no inlet or outlet. Superimposed on the map are representative specimens of species and ecotypes inhabiting the lakes.