The morphology of the two marine urostyloid ciliates, Pseudokeronopsis carnea (Cohn, 1866) and Uroleptopsis citrina Kahl, 1932, in the family Pseudokeronopsidae, collected from the Yellow Sea, and the East Sea, Korea, respectively, were studied using live observation and protargol impregnation. Additionally, the small subunit ribosomal RNA (SSU rRNA) gene was sequenced. These two species are firstly recorded in Korea. The main diagnostic key is as follows. Pseudokeronopsis carnea: body outline elongate-elliptical, brown-reddish or orange-red in colour in vivo; bicorona of 16-24 frontal cirri; one buccal and two frontoterminal cirri; 7-10 transverse cirri; 5-7 dorsal kineties; two types of cortical granules (one orange- red pigment, mainly grouped around cirri and dorsal bristles, arranged in typical rubra-pattern; the other, colourless and blood-cell-shaped, and densely distributed); contractile vacuole in the posterior half of the cell on the left side, usually in posterior 1/3-2/5. Uroleptopsis citrina: body outline elongate-elliptical, lemon-yellow in colour in vivo; two types of cortical granules (one yellow pigment; the other, blood-cell-shaped, densely distributed); bicorona of 12-18 frontal cirri; 2-3 frontoterminal cirri; two midventral rows comprising 26-35 cirri (consisting of anterior paired cirri, non-paired single cirri, and posterior paired cirri); three dorsal kineties. In addition, the SSU rRNA sequ-ences of the two species were compared with public database of these species and consequently, showed high similarity.
The genera
The
Kahl (1932) established the genus
In this study, we described two marine ciliates new to Korea,
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Sample collection and identification
The specimens of
After collection and isolation, specimens were maintained in the laboratory, either as pure or raw cultures in Petri dishes and 50 mL tissue culture flasks (Greiner Bio-one, Fricken-hausen, Germany). Autoclaved seawater was supplied with putting rice grains as a substrate for bacterial growth (Jung et al., 2011). The living specimens were observed under a light microscope ( Leica DM2500; Leica Microsystems, Wetzlar, Germany) at 50-1,000 magnification. Protargol impregnation was applied according to Foissner (1991) to reveal the infraciliature.
Terminology and classification are mostly according to Berger (2006) and Lynn (2008).
A cell (single specimens of each species) was transferred to a 1.5 mL microtube with a minimum volume of water. Geno-mic DNAs were extracted using a RED-Extract-N-Amp Tis-sue PCR kit (Sigma, St. Louis, MO, USA), according to the manufacturer’s protocol. The nearly complete SSU rRNA genes were amplified by polymerase chain reaction (PCR) with the universal eukaryotic primers: New EukA (5?-CTG GTT GAT YCT GCC AGT-3?), modified from Medlin et al. (1988), and LSU rev3 (Sonnenberg et al., 2007) primers. The optimized conditions for this process were as follows: Denaturation at 94℃ for 3 min followed by 35 cycles of denatura-tion at 95℃ for 15 sec, annealing at 58℃ for 30 sec, extension at 72℃ for 4 min, and then a final extension step at 72℃ for 7 min. The PCR products were purified with the QIAquick® PCR Purification kit (Qiagen, Valencia, CA, USA). Three internal primers were used for sequencing: 18S+810 (5?-GCC GGA ATA CAT TAG CAT GG-3?) and 18S-300 (5?-CAT GGT AGT CCA ATA CAC TAC-3?) and 18S+1470(5?-TCT GTG ATG CCC TTA GAT GTC-3?). Sequencing in both directions was conducted by an ABI 3700 Sequencer(Applied Biosystems, Foster City, CA, USA).
The sequencing fragments of the SSU rRNA gene were combined via BioEdit (Hall, 1999) and were aligned using Clustal X 1.81 (Jeanmougin et al., 1998). Mega 4.0 (Tamura et al., 2007) was used to calculate genetic distance by applying the Kimura two-parameter distance method (Kimura, 1980).
Korean name: 1*뚱뚱이홍색위각모충 (신칭)
Phylum Ciliophora Doflein, 1901
Class Spirotrichea Butschli, 1889
Order Urostylida Jankowski, 1979
Family Pseudokeronopsidae Borror and Wicklow, 1983
Genus Pseudokeronopsis Borror and Wicklow, 1983
1*Pseudokeronopsis carnea (Cohn, 1866)
Wirnsberger et al., 1987 (Table 1, Figs.1 A-D, 2)
[Table 1.] Morphometric characterization of Pseudokeronopsiscarnea
Morphometric characterization of Pseudokeronopsiscarnea
1987, Song et al., 2006: 271-287, figs.1 A-G, 2, 3, 9C, Tables .1-3
Material examined. One population was obtained from In-cheon harbor on November 2, 2010.
Description. Cell
The adoral zone of membranelles distinct, approximately 1/3 of the cell length, and composed of about 69 membran-elles(Fig.2 D, H). Bicorona of frontal cirri slightly enlarged,composed of about 8-12 cirral pairs, extending as a midven-tral complex consecutively. One buccal cirrus near the paro-ral membrane (Fig.2 H, arrow), whereas two frontoterminal cirri behind the distal end of the adoral zone (Fig.2 I, arrows); midventral complex distinctly separated rows (Fig.2 J), com-posed of 30-46 cirral pairs, terminating near transverse cirri; both posterior ends of marginal cirral rows not overlapped; 7-10 transverse cirri located between both posterior ends of the left and right marginal cirral rows (Fig.2 K). Almost no gap found between the midventral rows and the transverse cirri; from five to seven dorsal kineties (Figs.1 D; 2L, arrows).
Distribution. North Sea, German, Denmark, Mediterranean,Yugoslavia, China and Korea (this study).
Remarks. Cohn (1866) published
Eight species among the genus
The Korean population,
1*Genus
2*
Material examined. One population was obtained from Guryongpo, Pohang in September 2008.
Description. Cell
which are around both dorsal kineties and cirri; cortical gra-nules colourless, blood cell shaped, scattered throughout the cell body (Figs.1F, 3E, F).
The adoral zone of membranelles distinct; about 1/3 of cell length, and composed of about 40 membranelles (Fig.3 D, I), left anterior corner a minute process causing a break (Fig.3 C, D, arrowhead). Bicorona of frontal cirri slightly enlarged, composed of about 6-9 cirral pairs, extending as a midventral complex consecutively (Fig.3 I). Midventral complex distin-ctly separated rows, composed of 26-35 cirri containing anterior, single cirri (Fig.3 G, arrow) in middle portion, posterior portion. Two or three frontoterminal cirri behind the distal end of the adoral zone (Fig.3 I, arrows); invariably three dorsal kineties (Figs.1 H; 3C, arrows); of particular interest, there is no buccal cirrus and transverse cirri.
Distribution. Adriatic Sea, and Korea (this study).
Remarks. Kahl (1932) established the genus
[Table 2.] Morphometric characterization of Uroleptopsis citrina
Morphometric characterization of Uroleptopsis citrina
lows: presence of a buccal cirrus and the pattern of the mid-ventral complex. Circumstantially,
Also,
The Korean population,