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Updated: Jul 13, 2026

Generation and Long-term Maintenance of Nerve-free Hydra
Published on: July 7, 2017
New observations on green hydra symbiosis
Goran Kovacević1, Mirjana Kalafatić, Nikola Ljubesić
1Faculty of Science, University of Zagreb, Department of Zoology, Croatia. goran@zg.biol.pmf.hr
Abstract:
New observations on green hydra symbiosis are described. Herbicide norflurazon was chosen as a "trigger" for analysis of these observations. Green hydra (Hydra viridissima Pallas, 1766) is a typical example of endosymbiosis. In its gastrodermal myoeptihelial cells it contains individuals of Chlorella vulgaris Beij. (KESSLER & HUSS 1992). Ultrastructural changes were observed by means of TEM. The newly described morphological features of green hydra symbiosis included a widening of the perialgal space, missing symbiosomes and joining of the existing perialgal spaces. Also, on the basis of the newly described mechanisms, the recovery of green hydra after a period of intoxication was explained. The final result of the disturbed symbiosis between hydra and algae was the reassembly of the endosymbiosis in surviving individuals.
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