Figure 4.

Unrooted haplotype networks of the complete mtDNA control region of cichlids of the Midas Cichlid species complex from six crater lakes in Nicaragua. Circles represent unique DNA sequences, and their size reflects the number of individuals sharing a particular haplotype (see scale; note that scale is different for crater Lake Xiloá). Colors refer to different lakes, light blue represents in each case fish from elsewhere outside the given crater lake. Connections between haplotypes represent mutational steps. The central haplotype 'C', is the most common haplotype that is found in the large lakes and some of the crater lake populations.