Abstract:
Thelandros (Oxyurida: Pharyngodonidae) are very rare nematode parasites that occur in the alimentary canal of lizards, our current knowledge of the global species composition of Thelandros nematodes remains very limited. Furthermore, the molecular identification, population genetics, and phylogeny of Thelandros remain in their infancy because of the limited genetic databases (especially mitochondrial genomes). The systematic positions of the Pharyngodonidae and Oxyuridae families are uncertain. Thelandros nematodes were collected from the yellow-headed rock agama Laudakia nupta (Squamata: Agamidae), from Pakistan. These specimens were identified at the species level using integrated morphological methods, species assembly by automatic partitioning (ASAP), and Bayesian inference (BI) analyses. Moreover, the complete mitochondrial genome of the present materials was sequenced and annotated to enrich the mitogenomic data and investigate the pattern of mitogenomic evolution of the family Pharyngodonidae. Phylogenetic analyses were also performed to assess the systematic position of the superfamily Oxyuroidea in the order Oxyurida and the evolutionary relationships of the four orders Ascaridida, Spirurida, Oxyurida, and Rhigonematida based on the amino acid sequences of 12 protein coding genes of mitochondrial genomes using maximum likelihood (ML) and Bayesian inference (BI), respectively. One new species Theladros adamsoni sp. n. and one known species Thelandros popovi were examined using light and scanning electron microscopy. The results of the ASAP and BI analyses based on the ITS,12S, cox1, and cox2 sequences also supported that Theladros adamsoni sp. n. and Thelandros popovi represents species separated from congeners. Phylogenetic analyses based on the amino acid sequences of 12 protein-coding genes (PCGs) of mitochondrial genomes revealed that the present study also constructed the phylogenetic relationships of the orders Ascaridida, Spirurida, Oxyurida, and Rhigonematida based on the amino acid sequences of the 12 protein-coding genes (PCGs) of the mitochondrial genomes, using Maximum Likelihood (ML) and Bayesian Inference (BI) methods, respectively. The phylogenetic results indicated that the order Ascaridida is not monophyletic, while the superfamilies Ascaridoidea and Heterakoidea is monophyletic. The present phylogenetic results suggest that the traditional superfamily Heterakoidea could be elevated as the infra-order Heterakomorpha. Within the Oxyurida, the families Pharyngodonidae and Oxyuridae formed a sister group. Theladros adamsoni sp. n. and Thelandros popovi is described using an integrated method. Characterization of the complete mitochondrial genome of Theladros adamsoni sp. n. and Thelandros popovi reported for the first time. Mitogenomic phylogenetic results suggest the erection of an infra-order Heterakomorpha for the traditional superfamily Heterakoidea. The present findings enrich the mitogenomic data and global species diversity of Pharyngodonides nematodes and provide novel insights into the systematic position of the Oxyuroidae superfamily.
Page(s):
63-64
DOI:
DOI not available
Published:
Journal: 1st International Conference on "Recent Advances in Green Biotechnology and Climate Resilience", September 15-16, 2025, Volume: 1, Issue: 1, Year: 2025
Keywords:
phylogeny
,
mitochondrial genome
,
integrative taxonomy
,
Oxyuroidea
,
Lizard parasites