Ref ID : 2602
Agnes Ruttner-Kolisko; [Uber die labile Periode im Fortpflanzungszyklus der Radertiere]. Int.Revue ges.Hydrobiol. 49(3):473-482, 1964
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Clone cultures of Brachionus rubens, entirely amicticly reproducing at a temperature of 20 degrees C, were exposed to a low temperature of 6 degrees C during a short period. 45 hrs after the shock nearly 50% of the clone became mictic in connection with an increase of the reproduction rate. These results seemed to show that the shock retards the development of the early embryonic stages and that it is the retarding process which induces the mictic reproduction. But other experiments with single individuals and the statistical treatment of the development data of their offspring showed clearly that the development time of mictic animals is not longer than that of amictic ones and that it is not the low temperature itself but the shock effect which causes the offspring of an animal to become mictic. From these experiments the fact can be deduced that the labial period in the reproduction circle of Brachionus rubens is confined to the maturing and growing period of the amictic egg. It is the authers opinion that during these vulnerable period changes in the metabolism of the mother animal, induced by such a shock as mentioned above, cause the differences between "mictipar" and "amictipar" eggs; these differences do not prevent both kinds of egg to develop into females but influence the genus of the following generation.