The role of rare morph advantage and conspicuousness in the stable gold-dark colour polymorphism of a crater lake Midas cichlid fish

Increased occurrence of the rare golden color morph of Pacific chub Kyphosus sandwicensis in a no-take marine reserve

Pacific chub, Kyphosus sandwicensis, are typically gray but some individuals display a golden color morph. We estimated that the frequency of occurrence of the golden morphs increased significantly from 2007 (1.9%) and 2012 (2.6%) to 2017 (5.0%) inside a no-take marine reserve around Nihoa Island in the Northwestern Hawaiian Islands. While sporadic observations of a golden color morph have been noted for several other marine fish species, we provide a quantitative estimate of changes in the frequency of occurrence of the morph within a wild marine population.