Chytridium lagenaria Arg 066. Photo by Martha Powell

Chytridium lagenaria (Arg 066) is classified in the family Chytridiaceae within the Chytridiales and Chytridiomycota. It is collected from freshwater habitats associated with green filamentous algae, especially those which are moribund, and as a result, is considered a saprotroph and possibly a weak parasite. Accordingly the chytrid can grow as a saprotroph on pollen and on nutrient agar. The thallus consists of a spherical to subspherical sporangium and stout, richly branched rhizoids, which arise from a prominent spherical to fusiform apophysis. Zoospores emerge from a single operculate sporangial opening, remaining motionless for a few minutes as a mass before swimming away.  Molecular phylogenetic studies reveal this chytrid is monophyletic with the type species of the genus, Chytridium olla, as part of a larger clade with Phlyctochytrium planicorne comprised of species with a Group II-type zoospore ultrastructure (Vélez et al. 2011). Developmentally this chytrid is unusual in that the apophysis enlarges prior to the expansion of the encysted zoospore into a sporangium, making this strain of interest to understand the regulation of genes involved in early stages of thallus development.

Reference:

Vélez, C. G., P. M. Letcher, S. Schultz, M. J. Powell, and P. F. Churchill. (2011). Molecular phylogenetic and zoospore ultrastructural analyses of Chytridium olla establish the limits of a monophyletic Chytridiales. Mycologia 103: 118-130.