Ref ID : 4769
Josef Dieckmann; [Neubeschreibung der Morphogenese von Paraholosticha muscicola Kahl, 1932 (Ciliophora, Hypotrichida)] (Redescription of the Morphogenesis of Paraholosticha muscicola Kahl, 1932 (Ciliophora, Hypotrichida)). Arch.Protistenk 137:143-156, 1989
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The morphogenesis of Paraholosticha muscicola Kahl, 1932 is redescribed. Before division, a cell encysts and divides into two tomites. During this process the adoral membranelles, the undulating membranes and the frontal cirri are resorbed. Then, each tomite forms a wrap within the cyst and gets motionless. The marginal and ventral cirral rows as well as the dorsal kineties are resorbed. Morphogenesis starts with the appearance of new kinetosomes. An oral primordium is formed which quite early shows a differentiation into adoral membranelles. At the same time the anlagen of the marginal rows, the dorsal kineties and the undulating membranes as well as the anlagen of the fronto-ventral complex arise "de novo". In the frontal part of anlage 1 seven to ten cirri evolve which form the corona of frontal cirri; and more terminal develop the undulating membranes. Out of anlage 2 four to seven cirri of the corona of frontal cirri, two to six cirri of the left frontal short row and three to six buccal cirri differentiate, while out of anlage 3 five to ten cirri of the coronal of frontal cirri and five to twelve cirri of the right frontal short row differentiate. Both ventral rows develop out of the anlagen 4 and 5. After differentiating of the kinetome the two tomites hatch. Under unfavourable conditions P. muscicola forms resting cysts. Encystment as well as excystment can be induced under laboratory conditions. During excystment the morphogenesis is highly synchronous in most cells. 80-90% of the cells usually can be observed in the same stage. Morphogenesis during division is identical to that during excystment; all stages of morphogenesis are identical in both cases. Morphogenesis in P. muscicola is not different from morphogenesis in P. sterkii. Thus, P. muscicola is a typical representative of the genus Paraholosticha Kahl, 1932.