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CNAA / Theses / 2010 / July /

The role of some reproductive forms in invertebrate animals in productivity of aquatic ecosystems

Author: Arcan Elena
Degree:doctor of biology
Speciality: 03.00.16 - Ecology
Scientific adviser: Laurenţia Ungureanu
doctor habilitat, associate professor (docent), Institute of Zoology of the ASM
Scientific consultant: Ion Toderaş
doctor habilitat, professor, Institute of Zoology of the ASM


The thesis was presented on the 2 July, 2010
Approved by NCAA on the 6 October, 2010


Adobe PDF document1.49 Mb / in romanian


reproduction, ciliates, infusorians, rotifers, cladocerans, secondary productivity, polymorphism, number, the reproductive rate, parthenogenetic females, diversity, aquatic ecosystems


The structure of the Theses: introduction, four chapters, the synthesis of the results, conclusions and recommendations, bibliography with 224 cited sources, 143 pages of main text, 30 figures, 12 tables, 5 annexes, the obtained results are published in 9 scientific works. Key words: reproduction, ciliates, infusorians, rotifers, cladocerans, secondary productivity, polymorphism, number, the reproductive rate, parthenogenetic females, diversity, aquatic ecosystems. The domain of study - Biology.

The purpose of the work consists in estimation of the role of some reproduction forms quantification (binary division, conjugation, parthenogenesis) in secondary productivity formation in aquatic ecosystems on the example of Paramecium caudatum (Holotricha, Ciliophora), Brachionus plicatilis, B.rubens (Rotatoria, Nemathelminthes) and Daphnia magna (Crustacea, Arthropoda). Objectives: Identification of morpho-functional polymorphism and qualitative estimation of reproductive potential in protozoans; estimations of reproductive capacity in parthenogenetic females for some distant phylogenetic groups; estimation of the relation between generative and somatic productivity in experimental ecosystems, elucidation of the impact of some abiotic factors (temperature, trophic regime, milimetric waves of low intensity, biological active substances, coordinative compounds) on asexual reproductive process in P. caudatum.

The methodology of scientific research is based on the concepts exposed in works by T.Sounenborn (1970); К. Суханова (1968); К. Хаусман (1988); J. Dragesco (1986); В. Кокова (1982); А. Монаков (1998); И. Богатова (1980) and A. Chiorean (2009).

Novelty and the organization of the work. The obtained experimental results concerning the reproductive peculiarities of invertebrates were systemized. The sexual conjugated reproduction process was examined. There have been performed complex researches of hydrobionts, which include utilization of biological active substances in nutritive media. For the first time the character of action of milimetric waves of low intensity in dependence on the duration of emission in laboratory clone of Paramecium caudatum has been pointed out. The optimal concentrations of some chemical substances on the development of unicellular organism were determined.

The theoretical significance and the applicative value of the work: The determined regularities represent an important support in caring on the technological regulations of more effective cultivations of protozoans. The obtained results contribute to the significant completion of information concerning the intrapopulational processes and their importance.

The scientific results are implemented in the teaching process in the Biology and Soil Sciences Department of Moldova State University.