The use of molecular techniques in the taxonomy of water mites (Hydrachnidia, Acari)

Abstract

The Hydrachnidia (water mites) are a robust component of aquatic communities in terms of both abundance and species richness. They have colonized all types of freshwater habitats and are highly diversified in both lotic and lentic habitats. Over 6,000 species of Hydrachnidia have been described worldwide, representing eight superfamilies, 57 families, 81 subfamilies and more than 420 genera. Water mite systematics is continually subject to change and various modifications. Performing systematic revisions can lead to numerous misunderstandings and difficulties in comparing research results, as the same species can have different systematic names in different publications. The development of molecular biology techniques has popularized the use of genomic traits in taxonomic identification. Among various markers used to identify species, the most important is the gene encoding cytochrome c oxidase I (COI). Species identification based on this gene is known as ‘DNA barcoding’. The use of DNA barcoding was a breakthrough in molecular methods of species identification and has dominated research on invertebrates. It has become possible to identify not only new species, but also species that are difficult to distinguish using traditional methods. Water mites are organisms on which molecular analysis is still rarely performed, as compared to other groups of invertebrates. Fortunately, recent years have seen increasing use of molecular techniques to clarify the intricacies of Hydrachnidia taxonomy. Using DNA markers in the taxonomy of water mites enables definitive resolution of ambiguities in the case of numerous questionable taxa, which is of great importance in all other types of research on these organisms.

Keywords

• Molecular analysis
• DNA barcoding
• systematic revisions
• taxonomic identification