On the importance of robust species descriptions for Rotifera: re-descriptions of Synchaeta stylata and Synchaeta longipes and a comparison to Synchaeta jollyae

Comprehensive re-descriptions of the two morphologically similar species Synchaeta stylata Wierzejski, 1893 and Synchaeta longipes Gosse, 1887 were made with the aim of providing unique and unambiguous morphological character sets for the identification of each species. The re-descriptions revolve around a morphological analysis of the habitus of live and SEM-prepared individuals-with a focus on robust and easily discernible features-together with a comprehensive examination of the trophus. In addition, we also undertake a detailed comparison of these species with descriptions of Synchaeta jollyae Shiel & Koste, 1993, another morphologically similar species that has been described solely on the basis of preserved and partly contracted specimens. In so doing, we found no convincing morphological differences to S. stylata that are robust to potential preparation artefacts. We therefore recommend that a thorough re-examination of the taxonomic status of S. jollyae should be performed based on the sampling of live, unpreserved topotypes from the type locality of this species (Queensland, Australia).