Updating Biodiversity Studies in Loricate Protists: The Case of the Tintinnids (Alveolata, Ciliophora, Spirotrichea).

Species determination is crucial in biodiversity research. In tintinnids, identification is based almost exclusively on the lorica, despite its frequent intraspecific variability and interspecific similarity. We suggest updated procedures for identification and, depending on the aim of the study, further steps to obtain morphological, molecular, and ecological data.

Discrimination of closely related species in tintinnid ciliates: new insights on crypticity and polymorphism in the genus Helicostomella.

This study focuses on the utility of molecular markers for the discrimination of closely related species in tintinnid ciliates. We analyzed the ecologically important genus Helicostomella by sequencing part of the large-subunit rDNA (LSU rDNA) and the 5.8S rDNA combined with the internally transcribed spacer regions 1 and 2 (5.

Phylogeny of the order Tintinnida (Ciliophora, Spirotrichea) inferred from small- and large-subunit rRNA genes.

Concatenated sequences of small- and large-subunit rRNA genes were used to infer the phylogeny of 29 species in six genera of Tintinnida. We confirmed previous results on the positions of major clusters and the grouping of various genera, including Stenosemella, the paraphyletic Tintinnopsis, the newly investigated Helicostomella, and some species of the polyphyletic Favella. Tintinnidium and Eutintinnus were found to be monophyletic.

Utility of genetic markers and morphology for species discrimination within the order Tintinnida (Ciliophora, Spirotrichea).

We evaluated the small- and large-subunit rDNA (SSU and LSU, respectively) for their ability to discriminate morphospecies of tintinnid ciliates. Multiple individuals from 29 morphospecies were identified according to microscopically-observed characteristics of the lorica, and then sequenced for both loci (21 new species for SSU and all of them new for LSU). Sequences from public databases were included in our analyses, and two hypervariable SSU regions (V4 and V9) were separately examined.