Abstract: | A new cryptobiid flagellates, Cryptobia udonellae sp. n., is described from the excretory channels of Udonella murmanica. The body of flagellates is spindle-shaped. The flagellar pocket is subapical. Two flagella emerge from the pocket. One flagellum turns anterior and is forward-directed; the other flagellum is directed posterior and close to the ventral cell surface. The ventral groove is well developed. The cytostome opens just anterior to the flagellar pocket. The cytostome leads to the short cytopharynx. In the excretory channel of worms the flagellates C. udonellae sp. n. are attached to microvilli of epithelium or lay free in the lumen. Both flagellates have been studied with TEM. The unusual parasite system which involves organisms of four different phylums of animals has been described for the first time. |