title: Prepalintomic metamorphosis in Hyalophysa chattoni (ciliophora, apostomatida): Cytoplasmic ultrastructure.
abstract: The transformation of cytoplasmic structures during prepalintomic development in the apostome ciliate Hyalophysa chattoni was studied by transmission electron microscopy. The trophont's food mass was divided into large sectors in the swimming stages (I, II), into globular masses in the cystic stages III, IV, and finally into typical oblate pellets in stage V. The oral fiber was observed in stages I-III and the rosette was observed in stages I, II and reappeared after division (stage VI), indicating that resorption occurred in stages IV and V; however, no signs of resorption were observed in either organelle. Mitochondria showed great variability in shape in stage II. Trichocysts increased abruptly in numbers in stage III and early stage IV. The water expulsion system of this species was found to possess ampullae, radial canals, and a smooth tubular spongiome in addition to the contractile vacuole.
authors.affiliation: Department of Zoology, North Carolina State University, Raleigh, North Carolina, USA.
authors.forename: N
authors.initials: N
authors.lastname: Rivaud