Monographic treatment of Paraholosticha muscicola (Ciliophora, Keronopsidae), including morphological and molecular biological characterization of a brackish water population from Korea

Al‐Farraj

et al. 2020

BMC Evol Biol

Background: Hypotrichia are a group with the most complex morphology and morphogenesis within the ciliated protists. The classification of Gastrostyla-like species, a taxonomically difficult group of hypotrichs with a common ventral cirral pattern but various dorsal and ontogenetic patterns, is poorly understood. Hence, systematic relationships within this group and with other taxa in the subclass Hypotrichia remain unresolved. Results: 18S rRNA gene sequence of a new Gastrostyla-like taxon was obtained. Phylogenetic analyses based on the 18S rRNA gene sequences indicate that this ciliate represents a new genus that is closely related to Heterourosomoida and Kleinstyla within the oxytrichid clade of the Hypotrichia. However, the position of this cluster remains unresolved. All three genera deviate from the typical oxytrichids by their incomplete (or lack of) dorsal kinety fragmentation during morphogenesis. Morphology and morphogenesis of this newly discovered form, Heterogastrostyla salina nov. gen., nov. spec., are described. Heterogastrostyla nov. gen., is characterised as follows: more than 18 fronto-ventral-transverse cirri, cirral anlagen V and VI develop pretransverse cirri, and dorsal ciliature in Urosomoida-like pattern. Conclusions: Similar to the CEUU-hypothesis about convergent evolution of urostylids and uroleptids, we speculate that the shared ventral cirral patterns of Gastrostyla-like taxa might have resulted from convergent evolution.

Section: Introductionmentioning

confidence: 99%

The insights into the systematic relationship of Gastrostyla-affinitive genera, with report on a new saline soil ciliate genus and new species (Protozoa, Ciliophora)

Al‐Farraj

et al. 2020

BMC Evol Biol

“…Hypotrichous ciliates are a highly differentiated group within ciliated protists, and have diversi ed morphological features and complicated morphogenetic processes [1][2][3][4][5][6][7][8]. To date, many studies have been carried out on the classi cation and phylogeny of hypotrichs [9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Morphology, morphogenesis and phylogeny of the new soil ciliate, Bistichella granulifera n. sp. (Protista, Ciliophora)

Lyu¹,

et al. 2020

Preprint

Background: Hypotrichous ciliates are showing extremely morphological diverse and complicated morphogenesis. However, many hypotrichs are still unknown/poorly-known and need to be explored. Recently, Foissner (2016) reassigned the species in Bistichella and Parabistichella. Due to lack of morphological and morphogenetic information, some problems were overlooked. In present work, a new species, Bistichella granulifera n. sp., was found in northern China. Based on its infraciliature, ontogenesis analyses and phylogenetic study, the phylogenetic position of Bistichella was discussed.Results: Bistichella granulifera n. sp. was characterized by having elongated oval body, two macronuclear nodules, cortical granules present, three frontal and three or four buccal cirri, three frontal rows with seven to ten cirri, usually two frontoventral rows with the left one usually terminates at 90% down length of body and no breaks in the right one. The main morphogenetic features of the novel species were as follows: (1) the posterior part of the old adoral membranelles is renewed; (2) frontoventral-transverse cirral anlagen III to V each form a frontal row, and anlagen VI to n each produce a frontoventral row; (3) both marginal rows and dorsal kineties develop intrakinetally; (4) the macronuclear nodules fuse to form a single mass. The gene sequence of Bistichella was investigated for the first time. Phylogenetic analyses based on the SSU rDNA sequences showed that the Bistichella groups with the non-dorsomarginalian hypotrichs.Conclusions: Morphology, morphogenesis and phylogenetic position of Bistichella granulifera n. sp., was investigated. Each frontoventral row originates from one anlage and only three bipolar dorsal kineties are present in the new species, which means it should belong to non-Dorsomarginalia rather than Amphisiellidae. Even though Bistichella has a close relationship with amphisiellids, due to the limited gene sequence, the phylogenetic position of Bistichella needs more data to be fully understood.

“…The Hypotricha Stein, 1859 is a speciose and morphologically diverse group that inhabits a wide range of biotopes [1][2][3][4][5][6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Morphology, Ontogeny and Molecular Phylogeny of a New Urostylid Ciliate, Bakuella (Pseudobakuella) Guangdongica n. sp. (Protista, Ciliophora, Hypotrichia) from Southern China

et al. 2020

Preprint

Background: Spirotrich ciliates are one of the most diverse groupsin the phylum Ciliophora and are widely distributed in marine, freshwater, and terrestrial biotopes. Many nominal species are, however, poorly known and their systematic positions remain uncertain due to the lack of information concerning their infraciliature, morphogenesis, and gene sequences. In this paper, the morphology and morphogenesis of Bakuella (Pseudobakuella) guangdongica n. sp. were studied, in addition, genomic DNA was extracted in order to sequence the small subunit rDNA. Results: Bakuella (Pseudobakuella) guangdongica n. sp. is characterized by 150–225 µm in vivo; 35–42 adoral membranelles; three to five buccal, two frontoterminal and eight to 13 transverse + pretransverse cirri; midventral complex comprised of 10–20 midventral pairs and two midventral rows extending to transverse cirri; posterior part of marginal rows slightly overlapped; colorless cortical granules about 1 μm across, arranged in small groups; soil habitat. Its main ontogenetic features are: (1) in the proter, the parental adoral zone of membranelles is completely renewed by new structures; (2) in the opisthe, the oral primordium originates apokinetally, some old midventral cirri join the formation of frontoventral-transverse cirral anlagen; (3) the anlagen for marginal rows and dorsal kineties develop intrakinetally; and (4) the numerous macronuclear nodules fuse into a single mass before dividing. Phylogenetic analyses based on the SSU rDNA sequence suggests the non-monophyly of the genus Bakuella. Conclusions: The morphology, morphogenesis and molecular phylogeny of the new hypotrichous ciliate, Bakuella (Pseudobakuella) guangdongica n. sp. were studied, the phylogenetic analyses show that the Bakuella is polyphyletic in the SSU rDNA.