Assorted zebrafish. From top to bottom: wild-type zebrafish (Danio rerio), with a striped pattern; fms mutant fish lacking yellow xanthophores and a nacre mutant fish lacking melanophores, both lack stripes; reintroduction of missing pigment cell type in fms or nacre mutants restores the pattern locally; a heterozygous and a homozygous obelix/jaguar mutant, revealing widened stripes and intermingled domains, respectively; a weak and a strong leopard mutant, revealing wavy stripes and spots, respectively; and lastly, Danio choprei, the closest relative of zebrafish, with a vertical bar pattern.