Catenochytridium Hemicysti N. Sp.: Morphology, Physiology and Zoospore Ultrastructure

ABSTRACT

Catenochytridium hemicysti is a monocentric chytrid with exogenous-endogenous development. A prosporangium develops inside the germ tube and the incipient sporangium develops from the outflow of protoplasm through the zoospore cyst. The zoospore cyst ruptures longitudinally and remains appended to the base of the sporangium. Sporangia are operculate, the single operculum is flexuous and folds up or collapses. Zoospores are released as a globose mass, and almost at once drift apart before swimming away. C. hemicysti utilizes glucose, cellobiose, sucrose, lactose, galactose, starch, cellophane (cellulose), and xylan (hemicellulose). It utilizes organic, ammonium and nitrate nitrogen, and it requires thiamine. It has a zoospore similar to Nowakowskiella, Cladochytrium and Allochytridium. The systematic relationship of Catenochytridium to Chytridium and Diplochytridium is discussed.

Key Words:

• Catenochytridium
• Chytridiales
• zoospore
• ultrastructure
• nutrition