Taxonomy and SSU rRNA gene-based phylogeny of two new Euplotes species from China: E. chongmingensis n. sp. and E. paramieti n. sp. (Protista, Ciliophora)

Abstract

Background The genus Euplotes Ehrenberg, 1830, one of the most complicated and confused taxa, contains about 160 nominal species. It was once proposed to be divided into four genera, two of which were proved to be non-monophyletic. At least 19 new species have been discovered in the past decade, implying that there is a large undiscovered diversity of this genus. Results The morphology of two new freshwater euplotid ciliates, Euplotes chongmingensis n. sp. and E. paramieti n. sp., isolated from Shanghai, China, were investigated using live observations, protargol staining, and Chatton-Lwoff silver staining method. Euplotes chongmingensis is characterized by its small size (40–50 × 25–35 μm), about 24 adoral membranelles, 10 frontoventral cirri, two marginal and two caudal cirri, eight dorsolateral kineties with 11–16 dikinetids in the mid-dorsolateral kinety and a double type of silverline system. Euplotes paramieti n. sp. is 180–220 × 110–155 μm in vivo and strongly resembles E. amieti but having a difference of 57 bp in their SSU rRNA gene sequences. Phylogenetic analyses based on SSU rRNA gene sequence data were used to determine the systematic positions of these new taxa. Conclusions The description of two new freshwater taxa and their SSU rRNA gene sequences improve knowledge of biodiversity and enrich the database of euplotids. Furthermore, it offers a reliable reference for environmental monitoring and resource investigations.

A new contribution to the raptorial ciliate genus Lacrymaria (Protista: Ciliophora): a brief review and comprehensive descriptions of two new species from Changjiang Estuary

“…However, little attention has been given to the family Lacrymariidae. A project on ciliate fauna conducted in Changjiang Estuary has led to the discovery of various new or rarely known ciliates (Chen et al, 2022;Han et al, 2022;He et al, 2022;Zhang Z. et al, 2022a,b). As a new contribution, we investigated the phylogeny and taxonomy of two new Lacrymaria species, namely, L. songi sp.…”