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

Abstract

Two populations of Epistylis wuhanensis n. sp., a new freshwater peritrich ciliate, were isolated from different freshwater ponds located in Hubei, China. Their morphological characteristics were investigated using live observation, protargol impregnation, and scanning electron microscopy (SEM). Specimens from the two populations showed identical arrangement of the infraciliature and identical small subunit ribosomal RNA (SSU rRNA) gene and ITS1-5.8S-ITS2 sequences. The zooids present bell-shaped and 90-175 × 27-54 μm in vivo. Macronucleus is variable in shape and located in the middle of cell. Pellicle is usually smooth with 139-154 and 97-105 striations above and below the trochal band, respectively. SSU rRNA gene and ITS1-5.8S-ITS2 sequences of E. wuhanensis n. sp. did not match any available sequences in GenBank. Phylogenetically, E. wuhanensis n. sp. clusters with the other Epistylis within the family Epistylididae, but is distinct from the major clades of Epistylis. Above all, the morphological characteristics and molecular analyses support that the present Epistylis is a new species. Expanded phylogenetic analyses of sessilids based on both SSU rRNA gene sequences and ITS1-5.8S-ITS2 sequences reveal that the genus Epistylis consists of Epistylis morphospecies and taxonomic revision of the genus is needed.

First diagnosis of ectoparasitic ciliates (TrichodinaandChilodonella) on farmed juvenile yellow catfish,Tachysurus fulvidracoin China

“…Similar to other commercial aquaculture industries worldwide, the T. fulvidraco fish farming industry has experienced multiple outbreaks of ectoparasitic ciliates. It is known that ectoparasitic ciliates can cause massive economic losses in aquaculture systems (Basson & Van As, ; Bastos Gomes, Jerry, Miller, & Hutson, ; Wang, Zhou, & Gu, ; Wang, Zhou, Guo, & Gu, ). However, the data on ectoparasitic ciliates that can infest T. fulvidraco are limited (Wang, Zhou, & Gu, ; Wang, Zhou, Guo, et al, ).…”

“…Trichodina species have long been considered a primary cause of disease outbreaks in cultured fish (Abdel‐Baki et al, ; Maciel, Garcia, Chagas, Fujimoto, & Tavares‐Dias, ; Saha, Bandyopadhyay, & Göçmen, ; Tang, Zhang, & Zhao, ; Valladao, Gallani, Padua, Martins, & Pilarski, ; Wang, Zhou, Guo, et al, ). Basson and Van As () pointed out that the larval and juvenile stages of fish are the most susceptible to Trichodina infestation.…”

“…outbreaks of ectoparasitic ciliates. It is known that ectoparasitic ciliates can cause massive economic losses in aquaculture systems (Basson & Van As, 2006;Wang, Zhou, Guo, & Gu, 2017).…”

“…However, the data on ectoparasitic ciliates that can infest T. fulvidraco are limited Wang, Zhou, Guo, et al, 2017). Ectoparasitic ciliates are protozoan parasites that are considered highly harmful to cultured fish.…”

First molecular identification of Vorticella sp. from freshwater shrimps in Tainan, Taiwan

“…However, compared with genera mentioned above, a number of species of Vorticellidae have been studied using modern molecular methods combined with morphological characteristics to properly assess the evolutionary relationships of the species for future taxonomic revisions ( Sun et al., 2013a ; Wang et al., 2017 ). Although a certain number of Vorticellidae are free-living, most species are epibionts attached to various aquatic organisms.…”