Pseudouroleptus jejuensis, Jung & Park & Min, 2014

Jung, Jae Ho, Park, Kyung Min & Min, Gi Sik, 2014, Morphology and Molecular Phylogeny of Pseudouroleptus jejuensis nov. spec., a New Soil Ciliate (Ciliophora, Spirotrichea) from South Korea, Acta Protozoologica 53 (2), pp. 195-206 : 201

Ontogenesis of P. jejuensis ( Figs 4 , 5 )

Some of dividers (i.e., middle, late, and post-dividers) were observed and described.

Nuclear apparatus: Division of the nuclear apparatus proceeds as in most oxytrichids and urostylids ( Berger 1999, 2006). In mid-dividers, the macronuclear nodules fuse and become a single mass and micronuclei are inflated ( Fig. 4A ). Next, the macronuclear mass divides twice and the inflated micronuclei become split and finish the division. The micronuclei always lie on the left of the macronuclear mass during the ontogenesis.

Oral apparatus: During the ontogenesis, the parental adoral membranelles are very likely inherited unchanged. In mid-dividers, the adoral membranelles of the opisthe form their definite structure and shape. The undulating membranes are still not separated in both the proter and opisthe. Next, the distal ends of adoral zones form arches like question mark. The undulating membranes become split.

Ventral cirral pattern: In the mid-dividers, cirral anlagen I–VI are formed between right frontoventral row and adoral zone ( Fig. 4B ). Anterior portions of anlagen IV and VI are separated from the posterior portions. Left frontoventral row is very likely composed of these anterior portions of anlagen IV and VI, and entire anlage V. The rearmost cirrus of anlage IV migrates posteriorly below adoral zone ( Figs 4D , 5B, D , arrowheads).

Marginal cirral rows: As usual the marginal cirral anlagen are developed within the parental rows and replace the parental structures. Dorsomarginal kineties are not found.

Dorsal ciliature: In the mid-dividers, the dorsal kineties 1–3 anlagen extend to the ends of the cell. Next, the kinety 3 anlage is split into three fragments, namely dorsal kineties 3–5 ( Fig. 4C , double arrowheads). Caudal cirri are developed at the posterior portions of kineties 1, 2 anlagen only ( Figs 4C , 5A, C , arrows). The caudal cirri are not found from kinety 3 anlage, even in late and post-dividers ( Figs 5A, C ).

Sequence analysis: The SSU rRNA gene sequence of P. jejuensis is 1,561 bp long and was deposited in the GenBank under accession number KF471024. Pseudouroleptus jejuensis was clustered with P. caudatus DQ 910904 and this clade was highly supported by all trees (NJ/ML/BI, 100/100/1.00) ( Fig. 4 ). The K2P distance between P. jejuensis and P. caudatus was 0.71%.

Occurrence and ecology: As yet found only at the type locality of Jeju Island. Pseudouroleptus jejuensis was isolated from a soil sample that was dark-brown coloured and covered with litter ( Celtis sp. ).

Figures

Figs 4A–D. Pseudouroleptus jejuensis, middle (A, B) and late divider (C, D) after protargol impregnation. Note that the parental dorsal bristles are shown by single dots although still composed of dikinetids. The parental dorsal dikinetids become smaller and are less impregnated than newly developed one. A, B – dorsal (A) and ventral (B) views of middle divider showing dorsal kineties and cirral anlagen. C, D – dorsal (C) and ventral (D) views of late divider showing dorsal kinety 3 fragmentation (double arrowheads). Note that caudal cirri are developed at posterior end of kineties 1, 2 only (arrows). Postperistomial cirrus (arrowheads) is originated from the anlage IV and split from anterior part of the anlage. IV–VI – cirral anlagen IV–VI. Scale bars: 150 μm.

Figs 5A–D. Pseudouroleptus jejuensis, late (A, B) and post-dividers (C, D) after protargol impregnation. Note that the parental dorsal bristles are shown by single dots although they are still composed of dikinetids. A, B – dorsal (A) and ventral (B) views of late divider showing caudal cirri (arrows) and posteriorly migrating postperistomial cirrus (arrowheads). Note that the caudal cirri are not developed from dorsal kinety anlage 3. C, D – dorsal (C) and ventral (D) views of post-dividers. The two post-dividers were fixed from a single dividing cell im- mediately after the complete cell division. Some of parental dorsal bristles and cirri are still observed, and postperistomial (arrowheads) and caudal cirri (arrows) migrate forward to their final position. 3–5 – dorsal kineties 3–5. Scale bars: 150 μm.