Phylogenetic position of Zeldia punctata (Nematoda: Cephalobidae) using 28S rDNA from Limpopo Province, South Africa

The Cephalobidae (Free-living nematodes) family are bacterivores that inhabit soil. Bacterial-feeding nematodes are one of the main consumers of soil bacteria. Therefore, study on this group of nematodes is essential. This molecular study was conducted in 2024 at Limpopo University to identify the free-living bacterivores nematodes from South Africa's soils, using a 28S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the Chelex method. The nematode was identified as Zeldia punctata. Afterwards, 28S rDNA was amplified using specific primers to identify the nematode. The Nblast analysis based on the 28S rDNA showed South African Z. punctata has 98% similarity (DQ145662) with the American population. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as Z. punctata in the same clade with highly supported (94%) bootstrap values. In conclusion, this species was properly identified using 28S rDNA. However, other rDNA markers are recommended to better understand Zeldia phylogeny.