Pavel Karel Bystřický

1 Introduction Cryptic diversity is increasingly being discovered in many established invertebrate taxa due to the constant development of molecular methods (Pérez-Ponce de Léon and Poulin 2016; Fišer et al. 2018). Cryptic species are phenotypically very similar, and therefore, their distinction is usually based on molecular, behavioural or ecological traits rather than on the traditionally used morphological characteristics (Bickford et al. 2007).