Vahlkampfia Chatton et Lalung-Bonnaire, 1912

Patsyuk, M. K., 2016, New Finds Of Naked Amoebae (Protista) In Water Reservoirs Of Ukraine, Vestnik Zoologii 50 (4), pp. 291-300 : 297-299

Genus Vahlkampfia Chatton et Lalung-Bonnaire, 1912

The species belonging to the genus Vahlkampfia are of the eruptive morphotype. It is a group of small limax amoebae which move fast and constantly change the direction of their locomotion. Uroidal structures are absent. Most species have single nuclei and are capable of forming cysts.

They live in fresh and salt water and in soil ( Alimov, 2000).

Vahlkampfia spp. are known from the water bodies of Europe, Antarctica, North America ( Page, Siemensma, 1991).

The amoebae found were rather small and belonged to the eruptive morphotype ( fig. 7 ). The cytoplasm moves fast, eruptively. The wave of the hyaloplasm rolls along all sides of the cell. The process is followed by the loss of the monopodial shape. When in motion, the posterior end is drawn to the anterior one, and as a result the cell becomes globular. Definitive uroidal structures are absent. The cell is 20–25 µm long, 8–12 µm wide, and the L/B ratio is 1.6–3.0. The single nucleus is 2.4 µm in diameter.

We have previously found the species in the water bodies of Zhytomyr, Kyiv and Volyn Polissya ( Patcyuk, Dovgal, 2012; Patsyuk, 2014 c). Here we report a new locality, a river in Korivka village (Kalynivka District, Vinnytsia Region).

The species of amoebae found in the present study in the water bodies of Ukraine ( Saccamoeba sp. , Ripella sp. , V. lata , Thecamoeba sp. , Acanthamoeba sp. , and Vahlkampfia sp. ) belong to monotactic, fan-shaped, striate, acanthopodial and eruptive morphotypes. For most of these amoebae, morphological data are not sufficient to definitely identify the species, so the majority of them were identified to the genus level herein. The list of naked amoebae of Ukraine was complemented by two new species: Acanthamoeba sp. and Thecamoeba sp. , which had not been registered in previous studies, and one new morphotype — the acanthopodial one.

Additional studies involving molecular methods are necessary for exact species identification of the amoebae found. The studies might include the investigation of 18S rRNA gene that was reported to be a variable locus in amoebae ( Smirnov, 2011). Besides, the Cox1 mitochondrial gene was proposed as a universal species marker for amoebae ( Kudryavtsev, 2014).

The author is thankful to Drs A. Smirnov, A. Goodkov, and L. Chistyakova for advising on the methods of investigation and identification of naked amoebae, Dr. V. Kharchenko for assistance with the use of the microscope Zeiss Axio Imager M1, Drs I. Dovgal and Yu. Kuzmin for their useful comments to the manuscript.

Figures

Fig. 7. Vahlkampfia sp.: 1–8 — lo- comotor forms, ×1240.