Molecular and ultrastructure characterization of two nematodes (Thelandros scleratus and Physalopteroides dactyluris) based on ribosomal and mitochondrial DNA sequences

The phylogenetic relationships of the nematode species Thelandros scleratus (Oxyurida: Pharyngodonidae) and Physalopteroides dactyluris (Spirurida: Physalopteridae) were analyzed using the ribosomal 18S rRNA and the mitochondrial cytochrome C oxidase subunit genes. The nematodes were recovered from Brook's house gecko, Hemidactylus brooki (Reptilia: Gekkonidae) from Hastinapur, Meerut (U.P.), India. The results demonstrated that T. scleratus shows 100% similarity with another sequence available from the same species and a close relationship (98-99%) with species of Parapharyngodon in both 18S rRNA and cox 1 regions. Regarding the nematode Physalopteroides, analysis showed a close phylogenetic relationship between P. dactyluris and several species of Physaloptera. This is the first sequence of 18S available for any species of the genus Physalopteroides.