Trachelotractus entzi ( Kahl, 1927 ) Foissner, 1997

Long, Hongan, Song, Weibo, Al-Rasheid, Khaled A. & Gong, Jun, 2009, Three marine haptorid ciliates from northern China: Paraspathidium apofuscum n. sp., Trachelotractus entzi (Kahl, 1927) Foissner, 1997 and Apotrachelotractus variabialis Long, Song and Warren, 2009 (Protozoa, Ciliophora), Journal of Natural History 43 (29 - 32), pp. 1749-1761 : 1753-1756

Trachelotractus entzi ( Kahl, 1927) Foissner, 1997

( Figures 3 , 4 , 8 ; Table 2)

Remarks

The morphology and infraciliature of the Qingdao population of Trachelotractus entzi , which is the first report of this ciliate from China, corresponds well with former studies ( Kahl 1927; Dragesco 1960; Foissner 1997a; Figure 8A–C ). Here, we provide a brief redescription and some photomicrographs for this species.

Description of the Qingdao population

Body vermiform, highly contractile and flexible ( Figures 3A, 3B , 4A, 4C–E ). Contracted cells ca. 250 × 40 µm and extended ones can reach ca. 750 × 30 µm. “Head” bulkier than posterior region, and filled with numerous dark granules, body widest at trunk ( Figures 3B , 4A–E ). One contractile vacuole terminally located, pore opening at posterior end of cell ( Figures 3A, 3B, 3F, 3I , 4A, 4C, 4D ). Somatic cilia 4 µm long in vivo. Extrusomes thread-, fibril- or rod-like, randomly distributed in the cytoplasm, 2–16 µm long ( Figure 3E, 3G, 3J ). Pellicle coarse, composed of quadrangular units ( Figure 4F ). Locomotion by crawling between sand grains.

Note: CV, coefficient of variation in %.

Infraciliature shown in Figure 3C, 3D, 3I . Pharyngeal basket long ( Figure 3E ). Two short dikinetid brush kineties composed of ca. 30 kinetosomes in total. On average, 23 monokinetid somatic kineties on trunk, with several short kineties on the neck, forming a suture ( Figure 3d ). Kinetosomes in neck region interconnected by dense nematodesmata ( Figure 3E ). Numerous irregularly distributed, spherical or elliptical macronuclear nodules, number varying with cell size ( Figure 3J ).

Figures

Figure 3. Trachelotractus entzi (Kahl, 1927) Foissner, 1997 from live cells (A, B, F) and after silver nitrate (H) and protargol stainings (C–E, G, I, J). (A) a typical cell; (B) a not fullyextended cell; (C, I) infraciliature of anterior and posterior body portion, arrow marks the pore of contractile vacuole; (D) showing infraciliature in neck region, arrowheads mark the shortened somatic kineties; (E) showing pharyngeal basket (PB) and nematodesmata in neck region; (F) showing extended, contracted and half-extended cells (from right to left); (G) showing various extrusomes; (H) silverline system; (J) cytoplasm inclusions in trunk region. Notes: B, brush kineties; Ex, extrusome; FG, fat globules; Ma, macronuclear nodules; PB, pharyngeal basket; scale bars: 70 µm (A); 20 µm (G); 40 µm (J).

Figure 4. Photomicrographs of Trachelotractus entzi (Kahl, 1927) Foissner, 1997 from live cells (A–F). (A, D) half-extended cells; (B) anterior part of a cell; (C) a fully extended cell; (E) a highly winding cell, note the black “head” of the cell; (F) pellicle structure. Note: scale bars: 100 µm.

Figure 8. Trachelotractus entzi (Kahl, 1927) Foissner, 1997 (A–C) and Paraspathidium fuscum (Kahl, 1928) Fjeld, 1955 (D, E), from life (A, B, D) and after protargol impregnation (C, E). (A) lateral view, from Foissner (1997a); (B) a contracted cell, from Kahl (1927); (C) infraciliature of anterior part, from Foissner (1997a); (D, E) lateral view and infraciliature of anterior part, from Foissner (1997b). Note: scale bars: 200 µm (A); 90 µm (D).