part of start stage end stage iris portion of tissue argentum zebrafish_anatomy argenta ZFA:0005914 2019-05-29T15:43:36Z Iridophore layer of iris composed of a outer layer of regularly tiled iridophores and an inner layer of randomly arranged iridophores. The outer regularly tiled iridophores reflect blue green light. The light reflecting crystals in the iris iridophores are composed of anhydrous Beta-guanine. iridophore layer iris Ceri pharyngula:high-pec adult