Molecular Characterization of Host-Specific Raphidascaridoid Worms from the Gangetic Garfish (Teleostomi: Belonidae) in India

Abstract

The 18S rDNA gene analysis with Internal Transcribed Spacers 1 and 2, and Mit. coi gene analyses of 12 sequences from the host-specific nematodes parasitizing liver of garfish, Xenentodon cancila (Belonidae) revealed their monophyletic characterization. The purification of PCR products was done using Centri-Sep spin columns (Princeton Separations, Adelphia, New Jersey, USA) and sequenced by ABI 3730 auto sequencer Applied Biosystems. Their genetic heterogeneity on the basis of comparable sequences from gnathostomatoid genus, Gnathostoma, 16 anisakid and ascaridoid genera assisted these to be ascribed to a newer genus, Indospinezia multispinatum gen. et sp. n. under a newly erected tribe Indospineziinea tribe n. under family Goeziinae, as the morphological differentiation distinctly segregated their taxonomic identity. The fish host, X. cancila acted as the common intermediate as well as definitive host in the Gangetic riverine ecosystem at Allahabad, India. Though the newer worms had typical gnathostomatoid (fish spirurins) characters, yet the single-toothed unidentate spines, cervical sacs, and the number of caudal papillae, that comprised pre-cloacal foliate as well as 'sunflower' papillae, differentiated them from the spirurins. The postlabial double-ridged cuticular collar at the base of head, and an altogether different sclerotized oral lid-plate distinguished these worms from genus Goezia as well as spirurins. Therefore, the new genus, has been accommodated under a newly raised tribe, Indospineziinea tribe n.