Morphological and molecular characterization of Posthodiplostomum sp. (Digenea: Diplostomidae) metacercaria in the muscles of snakeheads (Channa punctata) from Manipur, India

Abstract

141 SummaryThe spotted snakehead, Channa punctata Bloch, 1793, is a locally important fish species commonly consumed by the natives in the state of Manipur, Northeast India. The fish host C. punctata from Lamphel area revealed a diplostomid metacercarial infection. Morphologically, the recovered metacercaria was identified as a species of Posthodiplostomum Dubois, 1936. Molecular characterization using the ribosomal RNA genes (rDNA 18S, ITS2 and 28S regions) and the mitochondrial CO1 region supplements the identification. Molecular analysis revealed the metacercaria to be closely related to Posthodiplostomum sp. Japan isolate, with sequence similarity variation from 97.5 -99.7 % while considering for the three rDNA markers. The secondary structure of the ITS2 region further corroborated these results; the typical four-helix model, when compared to the taxon from Japan, showed differences only in twelve bases (with seven transitions and five transversions). In phylogenetic analysis also, the metacercaria claded with the genus Posthodiplostomum, coming closer to the Japanese isolate, thus supplementing the morphological identification of the metacercaria.

Validity of the Diplostomoidea and Diplostomida (Digenea, Platyhelminthes) upheld in phylogenomic analysis

“…Posthodiplostomum, though nominally part of the family, is separate from and basal to a clade composed of other diplostomids and the Strigeidae. Posthodiplostomum belongs to the Crassiphialinae Sudarikov, 1960 and is consistently recovered with other members of this subfamily (e.g., Uvulifer, Bolbophorus, Ornithodiplostomum, Mesoophorodiplostomum and Posthodiplostomum in Athokpam and Tandon, 2014;Blasco-Costa and Locke, 2017;Hernández-Mena et al, 2017;López-Jiménez et al, 2017;Sereno-Uribe et al, 2018;Locke et al, 2010, see fig. S4).…”

Nuclear and mitochondrial phylogenomics of the Diplostomoidea and Diplostomida (Digenea, Platyhelminthes)1

“…Posthodiplostomum , though nominally part of the family, is separate from and basal to a clade composed of other diplostomids and the Strigeidae. Posthodiplostomum belongs to the Crassiphialinae Sudarikov, 1960 and is consistently recovered with other members of this subfamily (e.g., Uvulifer, Bolbophorus, Ornithodiplostomum, Mesoophorodiplostomum and Posthodiplostomum in Athokpam and Tandon, 2014; Blasco-Costa and Locke, 2017; Hernández-Mena et al, 2017; López-Jiménez et al, 2017; Sereno-Uribe et al, 2018; Locke et al, 2010, see fig. S4).…”

A case of severe infection of metacercariae from the liver of garfish Xenentodon cancila (Beloniformes: Belonidae): morphological and molecular evidence

“…The reason behind the unknown status of diplostomid parasites in India due to they has not been well studied and left a big gap in regard to their true diversity. However, in recent years, few studies pointed out it and contribute to the understanding of diplostomid parasites and tried to ll the gap behind [42][43][44][45][46][47] .…”