The Fine Structure of the Internal Spiral of Kinetosomes in Foettingeria's Tomite, a Unique Storage Depot for Kinetosomes¹

Abstract

ABSTRACT. The fine structure of the tomite of Foettingeria actiniarum (Claparède) was examined and compared with that of other apostome tomites. This stage in the life cycle has a unique configuration of kineties that form a spiral through the cytoplasm in the interior of the body. The structure and behavior of this internal spiral were evaluated as a mechanism for the storage of kinetosomes, an adaptation to the ciliate's two‐host life cycle. The spiral is composed of nine ribbons of laterally compressed kinetosomes that are in contact with a thin electron‐dense fibril. Paralleling the kineties of the spiral are conspicuous, swollen lamellae of the rough endoplasmic reticulum; these lamellae contain moderately electron‐dense material. The spiral is associated with the large contractile vacuole and winds about the macronucleus. The tomite of Foettingeria possesses a single, robust, caudal cilium located in a pit, along with the nozzle‐like pore of the contractile vacuole. The walls of the pit contain several trichocysts arranged radially about the caudal cilium and aimed into the pit.

Studies of the Phoront of Hyalophysa chattoni (Ciliophora, Apostomatida) Encysted on Grass Shrimp1

“…The lateral canal has been observed in Gymnodiniodes, Polyspira. and Foettingeria (2, 4, 14) and future work will probably show that it is present in all apostomcs. The canal is clearly involved in the formation of the cytostome in Hyalophysa.…”

Morphologie et Ultrastructure de Spirochona gemmipara Stein, 1852 (Ciliophora, Chonotrichida). III. Appareil de Fixation chez la Larve et chez l'Adulte1

“…Certains stades montrent, ventralement, une structure CtoilCe, initialement appelCe rosace (9,49) et ensuite rosette (26,50); celle-ci Cvoque irnmkdiatement la rosette de la larve du spirochone. La microscopie Clectronique (6,50,52) rCvkle que la rosette de divers Apostomes est une cavitC ovo'ide IimitCe par une pellicule de type alvColaire, et CquipCe de 13-16 septes minces et ondulCs; une dizaine de cils, implantCs dans le plafond de la rosette, battent entre les septes. La rosette communique avec l'atrium "buccal", lequel reGoit tgalement plusieurs "diverticules" et "canalicules", et de plus, s'ouvre sur l'extkrieur.…”

“…Cependant, dans le trophonte de Hyalophysa, la rosette s'ouvre directement sur I'extCrieur (7). Egalement limit& par une pellicule de type alvtolaire, les diverticules et canalicules rkcoltent, de toute Cvidence, le materiel contenu dans une quantitt de corpuscules cytoplasmiques appelks mucocystes (50) ou "inclusion bodies" (6,52). Enfin, le r61e fonctionnel de la rosette des Apostomatida n'est pas connu; selon divers auteurs, elle pourrait intervenir dans la reconnaissance du substrat, participer a I'Claboration du ptdoncule de fixation ou a la construction de l'enveloppe kystique.…”