Paraspathidium apofuscum, Long & Song & Al-Rasheid & Gong, 2009
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publication ID |
https://doi.org/ 10.1080/00222930902781038 |
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persistent identifier |
https://treatment.plazi.org/id/190A8793-4B05-1D2D-FE7F-F836376EFB4F |
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treatment provided by |
Felipe |
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scientific name |
Paraspathidium apofuscum |
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Genus Paraspathidium Noland, 1937 View in CoL View at ENA
Paraspathidium apofuscum n. sp.
( Figures 1 View Figure 1 , 2 View Figure 2 and 8 View Figure 8 ; Table 1)
Diagnosis
Highly contractile Paraspathidiium 130–250 µm long in vivo; single contractile vacuole terminally located, with no distinct collecting canals; 34–43 somatic kineties; dikinetid perioral kinety not forming a closed circle.
Type locality
Intertidal zone of a mesotrophic sandy beach near Qingdao (36°08′N; 120°43′E), China GoogleMaps .
Etymology
Composite of the Greek word apo- (unlike) and the known species name fuscum , meaning a ciliate different from the congener P. fuscum .
Description
Size ca. 200 × 40 µm in vivo, elongate, anterior end shaped like a knife-blade, posterior end rounded ( Figures 1A View Figure 1 , 2A, D View Figure 2 ). At rest, cells usually contracted and bucket-shaped ( Figure 2K View Figure 2 ). Anterior half of body full of dark granules, giving cell “half black, half transparent” appearance under low magnifications ( Figures 1A View Figure 1 , 2A, D View Figure 2 ). Extrusomes thread-like, 8 µm long, thinner in middle portion than at either end, widely distributed in cytoplasm especially around the slit-like, apically located cytostome ( Figures 1A, D, G View Figure 1 , 2G, H, I View Figure 2 ). Two ellipsoidal macronuclei, with one micronucleus between them ( Figures 1E, F View Figure 1 , 2J View Figure 2 ). One contractile vacuole, terminally located ( Figures 1A View Figure 1 , 2B, M, N View Figure 2 ). Somatic cilia ca. 7 µm long in vivo; and oral cilia ca. 12 µm ( Figure 1A View Figure 1 ). Generally inactive, often float in the water, occasionally crawling slowly among sand grains.
Infraciliature as shown in Figures 1E, 1F, 1H, 1I View Figure 1 , 2C, 2E, 2F, 2I View Figure 2 . On average, 37 somatic kineties present, each composed of monokinetids plus five to seven dikinetids in anterior portion ( Figures 1B, 1H, 1I View Figure 1 , 2C, 2E, 2F, 2I View Figure 2 ). Brush kineties composed of Note: CV, coefficient of variation in %.
three parts: (1) two short dikinetid kineties; (2) four or five short monokinetid kineties; (3) ca. 20 irregularly distributed kinetosomes ( Figures 1B, 1I View Figure 1 , 2E View Figure 2 ). Buccal apparatus located at anterior end of cell. Oral opening apical and irregularly elliptical ( Figure 2O View Figure 2 ). Perioral kinety, consists of ca. 50 pairs of kinetosomes, does not form a closed circle. Numerous fine fibres associated with the buccal margin ( Figures 1B View Figure 1 , 2E View Figure 2 ). Reticular silverline system consists of quadrangular parts, with one cross line going through the kinetosome in each part ( Figure 1C View Figure 1 ).
Remarks and comparison
Hitherto, Paraspahidium was a monotypic genus, the only species being P. fuscum ( Kahl, 1928) Fjeld, 1955 , which was redescribed by Foissner (1997b). Our new species differs clearly from P. fuscum in the following combination of characters: (1) fewer somatic kineties (34–43 vs. 50–60); (2) the absence of conspicuous dorsal brush (vs. the presence of conspicuous, highly differentiated dorsal brush; see Figures 2L View Figure 2 , 8D, 8E View Figure 8 ); (3) perioral kinety open (vs. closed in P. fuscum ) ( Figures 8D, 8E View Figure 8 ); (4) contractile vacuole without detectable collecting canals (vs. with several collecting canals extending to mid-body in P. fuscum ) ( Foissner 1997b).
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