Differential pigmentation in the sexual phase of Coelomomyces

Abstract

THE fungal mosquito parasite, Coelomomyces dodgei (Chytridiomycetes: Blastocladiales), produces gametophytes and gametangia of two different colours, light amber and bright orange, in the intermediate copepod host, Cyclops vernalis. Each gametartgium produces gametes of a corresponding colour. Experimental evidence is presented here which indicates that these differentially pigmented gametes are of opposite mating types, the light amber being female and the bright orange being male, and that zygotes capable of infecting mosquitoes, are produced by their fusion. This differential pigmentation provides a valuable marker for identifying gametes of opposite mating type for experimental purposes, and additionally provides further evidence for a phylogenetic relationship between Coelomomyces and certain other genera of the order Blastocladiales.