Diatoms on the carapace of European pond turtle (Emys orbicularis L.) in Vojvodina

Abstract

Epibiotic diatoms inhabiting the carapace of European pond turtle (Emys orbicularis Linnaeus, 1758) are examined between May and July 2017 from three locations in Vojvodina (Serbia): Special nature reserve „Deliblatska Peščara“, Natural monument „Ivankovačka ada“ and Special nature reserve „Gornje podunavlje“. Our objective was to compare the diatom flora on a single turtle species across part of its range. Diatoms were removed by brushing from the carapaces, preserved in 4% formalin and identified under Carl Zeiss AxioImager.M1 microscope after preparing permanent slides with Naphrax medium. The diverse diatom assemblages were recorded. A total of 116 diatom taxa from 32 genera were found on the carapace of European pond turtle. The highest diversity in epibiotic diatom community was recorded at SNP „Deliblatska Peščara“ and NM „Ivankovačka ada“ (85 and 81 taxa, respectively). Only 6 diatom taxa (Nitzschia denticula, N. fonticola, Fragilaria ulna, Cymbella parva, C. perparva and Cyclotella sp.) were found on all three localities. Of these species, Cymbella perparva i Nitzschia denticula were occurred on the greatest number of turtles. In contrast, 67 diatom taxa occurred only on a single locality. Diatom richness and abundance were variable both among and within localities. The most numerous were erect (Cymbella spp., Gomphonema spp.) and motile (Nitzschia spp., Navicula spp.) forms.