Influence of storage and examination methods on the recovery and size of metacercariae of Cyathocotyle bushiensis and Sphaeridiotrema pseudoglobulus (Digenea).

The recovery of metacercariae of Cyathocotyle bushiensis (Digenea: Cyathocotylidae) and Sphaeridiotrema pseudoglobulus (Digenea: Psilostomidae) from Bithynia tentaculata (Gastropoda: Prosobranchia) subjected to 3 methods of storage (70% alcohol, freezing, and fresh) and 2 methods of examination (crushing or artificial digestion) was evaluated. Prevalence and abundance of fully developed metacercariae of C. bushiensis and metacercariae of S. pseudoglobulus did not significantly vary as a result of storage or examination methods; however, digestion of frozen and fresh snails resulted in a significantly lower prevalence and abundance of not fully developed metacercariae of C. bushiensis. Furthermore, freezing or storing snails in alcohol may result in misclassification of the metacercariae of C. bushiensis. Both methods of storage and examination also affected the size of the metacercariae of both digeneans. Although digested snails were easier to examine, there appeared to be no overall gain in time by using digestion instead of crushing.