Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 3837

H. Norbert Lanners; Ultrastructure of the Fusion Area during Conjugation in the Suctorian Heliophrya erhardi (Rieder) Matthes. J.Protozool. 25(4):453-460, 1978

Reprint

In File

Notes

The suctorian Heliophrya erhardi (Rieder) Matthes is attached to the substrate by the flattened ventral side of the cell body. The dorsal side is covered by a pellicle composed of 3 unit membranes. Below the pellicle is a 0.4-0.8-µm thick epiplasm composed of 6-8-µm thick fibrils. Microtubules form a network beneath the epiplasm. The epiplasm is penetrated by tube-like pellicular pits, which are lined by the cell membrane and end beneath the epiplasm in a saccule-like enlargement. During conjugation, 2 neighboring organisms form cytoplasmic processes which come into contact and fuse, thus forming a cytoplasmic bridge between the 2 cells. Around the bridge the pellicles of both organisms fuse, and the partners become united by a continuous common membrane system. Across the entire conjugation bridge the 2 fused epiplasm form a septum. Tube-like structures can be seen lying partly in the epiplasm septum and partly in the adjacent cytoplasm. These structures are open at both ends and represent remnants of the pellicular pits. No trace of the original pellicular membranes can be found at the fusion area within the epiplasmic septum. The cytoplasm of the conjugation partners is separated only by the fused epiplasms forming the epiplasmic septum.