The planktonic freshwater ciliate Balanion planctonicum (Ciliophora, Prostomatea): A cryptic species complex or a "complex species"?

ABSTRACT: The globally distributed ciliate Balanion planctonicum is a primary consumer of phytoplankton spring blooms. Due to its small size (~20 μm), identification and quantification by molecular tools is preferable as an alternative to the laborious counting of specimen in quantitative protargol stains. However, previous sequencing of the 18S rDNA V9 region of B. planctonicum from Lake Zurich (Switzerland) and subsequent quantification by fluorescence in situ hybridization yielded significantly lower cell numbers than using morphotype counting. This raised the question of whether B. planctonicum shows a cryptic diversity or whether it is just a 'complex species' with intra-clonal polymorphisms. Over three years, we established numerous monoclonal cultures, and long-read sequencing of rDNA operons

SUBMITTER: Schalch-Schuler M 

PROVIDER: S-EPMC11771736 | biostudies-literature | 2025 Jan-Feb

REPOSITORIES: biostudies-literature