Apokeronopsis sinica, Liu, Weiwei, Li, Jiqiu, Gao, Shan, Shao, Chen, Gong, Jun, Lin, Xiaofeng, Liu, Hongbin & Song, Weibo, 2009

Liu, Weiwei, Li, Jiqiu, Gao, Shan, Shao, Chen, Gong, Jun, Lin, Xiaofeng, Liu, Hongbin & Song, Weibo, 2009, Morphological studies and molecular data on a new marine ciliate, Apokeronopsis sinica n. sp. (Ciliophora: Urostylida), from the South China Sea, Zootaxa 2005 (1), pp. 57-66 : 58-60

publication ID	https://doi.org/ 10.11646/zootaxa.2005.1.5
persistent identifier	https://treatment.plazi.org/id/C70BD62F-FF86-FFB5-0794-BC0E0946FA68
treatment provided by	Felipe
scientific name	Apokeronopsis sinica
status

Treatment

Apokeronopsis sinica View in CoL n. sp. ( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 ; Table 1)

Diagnosis: Medium sized marine Apokeronopsis , 150–200 × 50–65 µm in vivo; ellipsoid in shape with posterior end narrowed; two kinds of cortical granules: the smaller ones colorless and dot-like in shape; the larger ones discoid in shape, colorless or vermeil in color. Adoral zone composed of ca. 50 membranelles; about 20 cirri in frontal area which form the non-typical bicorona, 2 frontoterminal, ca. 4 buccal and 8–13 transverse cirri; midventral complex comprising of 21–32 pairs of cirri which conspicuously separated; 26–46 right and 19–35 left marginal cirri; invariably 3 dorsal kineties. Numerous macronuclear nodules. Contractile vacuole positioned in left anterior 2/5 of body.

Etymology: Named after the country discovered.

Type slides: One holotype and one paratype slides (registration number: WW 07112803 –01, WW 07112803 –02) of protargol-impregnated specimens are deposited in the Laboratory of Protozoology , South China Normal University, China.

Type locality: Coastal water of Clear Water Bay, Hong Kong (22° 20′ N; 114° 17′ E) GoogleMaps .

Morphological description: Size 150–200 × 50–65 µm in vivo, and 115–200 × 72–105 µm after protargol staining, body basically ellipsoid in shape with posterior end narrowed, both ends broadly rounded, left margin of anterior region ear-shaped, protruding to the left side and widest at 2/5 anterior portion ( Figs. 1A, B View FIGURE 1 ; 2A, B View FIGURE 2 ). Dorsal side evidently vaulted in center and cell is flattened 3:2 dorsoventrally ( Fig. 2C View FIGURE 2 ). Buccal field narrow, about 2/5 of body length.

Pellicle flexible, with two kinds of cortical granules on both ventral and dorsal sides ( Figs. 1C, D View FIGURE 1 ; 2E, I, J View FIGURE 2 ): the smaller ones colorless, dot-like in shape, about 0.2 µm in diameter, closely arranged in longitudinally oriented lines ( Figs. 1D View FIGURE 1 ; 2I View FIGURE 2 , double-arrowheads); the larger ones discoid in shape, about 2 µm across, sparsely distributed throughout whole body, showing two colors: mostly colorless, few vermeil in color ( Figs. 1D View FIGURE 1 ; 2I View FIGURE 2 , arrows). Cytoplasm colorless or grayish, containing many granular inclusions (2–5µm in size), which, as well as cortical granular, give the cell a dark brown, opaque appearance at low magnifications. In the posterior portion of cell, usually several food vacuoles containing some diatoms. Contractile vacuole about 15 µm across at end of diastole, positioned near posterior end of adoral zone of membranelles ( Fig. 2B View FIGURE 2 , arrow).

Most somatic cirri relatively fine, 10–15 µm long; cilia of adoral membranelles ( Fig. 2D View FIGURE 2 , arrows) and transverse cirri ca 20 µm long. Locomotion relatively slow, usually consists of slow crawling on substrate, with short and frequent pauses, quickly stopping and keeping stay when disturbed.

Infraciliature as shown in Figs. 1E, F View FIGURE 1 ; 2K View FIGURE 2 . Adoral zone of membranes ( AZM) curves along anterior cell margin and bends conspicuously posteriad along right margin; and proximal end of AZM extends somewhat obliquely towards buccal cavity ( Figs. 1E View FIGURE 1 ; 2L View FIGURE 2 ). Bases of membranelles ca. 10 µm in length. Paroral ( PM) ( Figs. 1E View FIGURE 1 ; 2L View FIGURE 2 , arrow) and endoral membrane (EM) ( Figs. 1E View FIGURE 1 ; 2L View FIGURE 2 , arrowhead) arched and optically intersected each other in posterior portion.

18–29 cirri in frontal area which form the non-typical bicorona, of which ca. 11 right ones arranged in a arc along anterior right margin, ca. 14 left ones arranged in an oblique line ( Figs. 1E View FIGURE 1 ; 2L View FIGURE 2 ). Two bicorona rows terminated anteriorly near AZM and not separated posteriorly from the midventral complex although in some specimens an inconspicuous gap was observed in the level of distal end of AZM ( Fig 1E View FIGURE 1 , arrow). Two frontoterminal cirri ( FTC) located between distal end of adoral zone and anterior end of right marginal row ( Figs. 1E View FIGURE 1 ; 2M View FIGURE 2 , arrowheads); mostly 4 buccal cirri (BC) lay close to paroral membrane ( Figs. 1E View FIGURE 1 ; 2M View FIGURE 2 , arrows). Midventral complex comprising of 21–32 midventral pairs, terminating just above the transverse cirri, the cirri of the pair conspicuously separated from each other ( Figs. 1E View FIGURE 1 ). 8–13 transverse cirri ( TC) densely arranged in a J-shaped row near posterior margin of cell ( Figs. 1E View FIGURE 1 ; 2O View FIGURE 2 , arrows). Cirri in marginal rows narrowly spaced; left marginal row ( LMR) commencing at the cytostome level. Marginal rows almost confluent posteriorly ( Fig. 1E View FIGURE 1 ). Bases of cirri associated with well impregnated fibers ( Fig. 2K View FIGURE 2 ). Dorsal cilia about 4 µm long, consistently arranged in 3 complete rows, which extend whole length of body, each comprising about 30 pairs of basal bodies ( Fig. 1F View FIGURE 1 ).

Abbreviations: CV = coefficient of variation in %; Max = maximum; Mean = arithmetic mean; Min = minimum; n = number of cells measured; SD = standard deviation.

Macronuclear segments (Ma) numerous, 150–200 in number, each spherical to elongate in outline, distributed in the whole body ( Figs. 1F View FIGURE 1 ; 2N View FIGURE 2 ). Micronuclei difficult to recognize.