Epistylis portoalegrensis n. sp. (Ciliophora, Peritrichia): A New Freshwater Ciliate Species from Southern Brazil

Abstract

The peritrich ciliate Epistylis portoalegrensis n. sp. was found in two bodies of freshwater located in Porto Alegre, Southern Brazil. Morphological features were investigated using live and protargol-stained specimens. The zooids presented a vase to cylindrical shape narrowed at the scopula, and a mean size of 131 × 37 μm in vivo. A C-shaped macronucleus lay in the middle of the cell close to a single contractile vacuole. The oral infraciliature was typical for the genus, with all infundibular polykineties composed by three distinct rows of kinetosomes. Colonies are often nonbranched with no lateral stalk, carrying several zooids stemming from a single point. Specimens from the two sampling sites showed identical arrangement of the infraciliature, similar morphometry, identical 18S rDNA sequences, and a single nucleotide difference across the more variable ITS regions. Molecular phylogenetic analyses placed E. portoalegrensis in a well-supported clade containing other Epistylis species, within the order Vorticellida.

Description of a New Freshwater Ciliate Epistylis wuhanensis n. sp. (Ciliophora, Peritrichia) from China, with a Focus on Phylogenetic Relationships within Family Epistylididae

“…In addition, a clade consisting of M. duplicatum and Zoothamnium nii was sister to a large clade containing Zoothamnium and major clades of Epistylis (clades II-IV) in the present phylogenetic analyses based on the ITS1-5.8S-ITS2 sequences. Although the phylogenetic analyses based on ITS1-5.8S-ITS2 sequences show different topologies from those inferred from the SSU rRNA gene sequences, the previous analyses based on SSU rRNA gene sequences reveal similar conclusions to those based on ITS1-5.8S-ITS2 sequences (Ji et al 2015;K€ uhner et al 2016). Hence, based on the result of phylogenetic analyses, we hypothesize that the major clades of Epistylis (except clade I) may experience secondary loss of the stalk spasmoneme and may evolve from some species of Zoothamniidae.…”

“…This conclusion is also corroborated by the molecular data reported here, which demonstrates that the SSU rRNA gene and ITS1-5.8S-ITS2 sequences collected from the two populations are identical (Tables 2, 3). The diverse morphometric characteristics presented above could be due to the environmental pressures, which have been observed in other peritrichs (Jiang et al 2016;K€ uhner et al 2016;Utz et al 2014). In addition, we consider that food source and appearance of food particles may be not a valid morphological feature.…”

“…; Kühner et al. ). Hence, based on the result of phylogenetic analyses, we hypothesize that the major clades of Epistylis (except clade I) may experience secondary loss of the stalk spasmoneme and may evolve from some species of Zoothamniidae.…”

“…However, compared with genera mentioned above, few species of Epistylis have been studied using modern molecular methods combining with morphological characteristics to properly assess the evolutionary relationships of species for future taxonomic revisions (Jiang et al 2016;K€ uhner et al 2016).…”

Host-parasite relationship during Epistylis sp. (Ciliophora: Epistylididae) infestation in farmed cichlid and pimelodid fish

“…Diseased fish were transported to the laboratory of invertebrate morphology of Universidade Estadual de São Paulo Júlio de Mesquita Filho for scraping observations of the living organisms with differential interference contrast microscopy, using an Axio Imager Z2 microscope (Carl Zeiss, Oberkochen, Germany). Parasite measurements were performed on living parasites, following methods normally used for this parasite (Ma & Overstreet, 2006;Kühner et al, 2016) and using the software Image Pro Plus (Media Cybernetics Inc., Rockville, MD, USA). Measurements are presented as mean±standard deviation (minimum-maximum, and number of structures measured).…”