Morrphological and molecular investigations on Sphatitiid ciliates (Ciliophora, Spathidiida) isolated from coastal sands of lake van

In this study, spathidiid ciliates living in sand and soil samples on the shores of Van Yüzüncü Yıl University campus were isolated, morphological and molecular phylogenetic properties were investigated. Three spathidiid populations with different morphological characteristics were observed in Petri cultures. Morphological features of these populations were revealed using live investigations and silver staining techniques. The 18S rDNA gene region of the isolated populations was amplified and gene sequences were determined. Comparing the gene sequences of the populations that reproduced one after another in the culture medium, it was found that all three populations had similar sequences. Due to this similarity, it was decided that the isolated populations were morphological variations in different life cycles of the same population. These populations were found to be close to Spathidium spathula in terms of cell shape, oral and somatic ciliature, and nuclear organization, but since the 18S rDNA gene sequence of the current population was very different from it, it could not be included in any species and reported as Spathidium sp. In this study, it was observed that the isolated Spathidium sp. population was in the same main clade as other spathidiid ciliates, but it was more closely related to Lagynophrya acuminata, Enchelys gasterosteus and Balantidion pellucidum rather than their congeners. There are many records in previous studies that there are incompatibilities between morphological and phylogenetic classification models of Haptorian ciliates. This problem may be due to the fact that the characters used in the morphological taxonomy of haptorid ciliates do not represent homology, and have emerged more than once in different lineages independently. To overcome this problem, it is recommended to re-evaluate the morphological taxonomy by identifying common morphological characters carried by genetically similar ciliates.