Species diagnostics of gastropod parasitic nematodes

Abstract: There are more than a hundred gastropod parasitic nematode species from twelve families (Agfidae, Alaninematidae, Alloionematidae, Angiostomatidae, Araeolaimidae, Ascarididae, Cephalobidae, Cosmocercidae, Diplogasteridae, Mermithidae, Panagrolaimidae and Rhabditidae). They may be morphologically divergent between major clades, but are usually conserved within each lineage. They may exist in different life stages, spending part or all of their life cycle in the host, making efficient and accurate species diagnostics challenging. Thus, most often, a combination of morphological, molecular and other tools is required. Species identification on obligate parasites require quick preservation both for morphological archiving and DNA sequencing. Facultative parasites may require additional process to culture but identification is possible without morpho-archiving. On the basis of higher sequencing success and increasing sequence availability, a fast and efficient approach would be targeting the D2-D3 domains of 28S rRNA for GenBank query.