Biodiversity analyses in freshwater meiofauna through DNA sequence data

Microscopic animals (also referred to as meiofauna) in freshwater habitats include several common, abundant and species-rich phyla, whose patterns of diversity are poorly known. Several approaches using DNA sequence data can be used to improve our knowledge on their biodiversity. In this review, we focus on studies using DNA data for taxonomy, and for environmental studies through metabarcoding on freshwater meiofauna. The results of the literature survey reveal that the use of DNA data is still rather limited. We screen the available literature on the topic and analyse the details of the current use and choices of the methods in freshwater meiofauna, the potential problems and limitations, and the flawed parts that still need to be improved. We conclude the review with a perspective on the still unexploited potentials in future applications to address biodiversity shortfalls in species diversity and taxonomy, and in the ecological and biogeographical patterns of species distribution.