Taxonomy of Two New Peritrich Ciliates (Protozoa: Ciliophora) from Inland Saltwaters of China

The inland saltwater lakes harbor exceptional biodiversity. Here, two new species of solitary sessile peritrich ciliates were isolated from Qinghai Lake, the largest inland saltwater lake in China. Their morphology, ciliature, silverline system, and molecular phylogeny were investigated based on live observation, silver staining, and analysis of the small subunit ribosomal DNA (SSU rDNA). Vorticella paraglobosa sp. n. is characterized mainly by its obconical or elongate bell-shaped zooid, C-shaped macronucleus, single ventrally located contractile vacuole, two-rowed infundibular polykinety 3, and 28–38 silverlines between peristome and aboral trochal band and 10–15 between aboral trochal band and scopula. Vorticella cotyliformis sp. n. differs from its congeners mainly by its double-layered peristomial lip, cup-shaped zooid, J-shaped macronucleus, single ventrally positioned contractile vacuole, three-rowed infundibular polykinety 3, and 70–85 silverlines between peristome and aboral trochal band and 21–25 between aboral trochal band and scopula. The SSU rDNA sequences of the two new species were obtained, and the subsequent molecular phylogenetic analysis supported their taxonomic classification.