The Morphology of Lagenidium Callinectes II. Zoosporogenesis

SUMMARYZoosporogenesis in the holocarpic marine phycomycete Lagenidium callinectes is initiated when actively growing mycelium is washed free of medium and placed in sea water. Portions of hyphae are walled off by septa and become the sporangia. Within the sporangia, first flagella form and later cleavage begins. From the sporangia, discharge tubes grow out. The partially differentiated cytoplasm flows through the discharge tube into a developing vesicle. There the laterally biflagellate zoospores complete their maturation and escape. After release, the “wall” of the vesicle disappears leaving an evacuated sporangium and a discharge tube with a flared end. Specialization of the zoospore is primarily concerned with the motile apparatus.