Melanophores Chromatophore

at bottom mutant zebrafish larva fails synthesise melanin in melanophores, @ top non-mutant, wildtype larva

melanophores contain eumelanin, type of melanin, appears black or dark-brown because of light absorbing qualities. packaged in vesicles called melanosomes , distributed throughout cell. eumelanin generated tyrosine in series of catalysed chemical reactions. complex chemical containing units of dihydroxyindole , dihydroxyindole-2-carboxylic acid pyrrole rings. key enzyme in melanin synthesis tyrosinase. when protein defective, no melanin can generated resulting in types of albinism. in amphibian species there other pigments packaged alongside eumelanin. example, novel deep (wine) red-colour pigment identified in melanophores of phyllomedusine frogs. subsequently identified pterorhodin, pteridine dimer accumulates around eumelanin core, , present in variety of tree frog species australia , papua new guinea. while other lesser-studied species have complex melanophore pigments, nevertheless true majority of melanophores studied date contain eumelanin exclusively.

humans have 1 class of pigment cell, mammalian equivalent of melanophores, generate skin, hair, , eye colour. reason, , because large number , contrasting colour of cells make them easy visualise, melanophores far studied chromatophore. however, there differences between biology of melanophores , of melanocytes. in addition eumelanin, melanocytes can generate yellow/red pigment called phaeomelanin.

the purple-striped dottyback, pseudochromis diadema, generates violet stripe unusual type of chromatophore.