Trichodina kazubski Van As & Basson, 1989

Tang, Fahui, Zhao, Yuanjun & Tao, Yanfei, 2007, Trichodinids (Ciliophora: Peritrichida) parasitic on gills of freshwater fishes, Carassius auratus and Aristichthys nobilis from China, with the description of Trichodina subtilihamata sp. nov., Zootaxa 1582 (1), pp. 39-48 : 44

Trichodina kazubski Van As & Basson, 1989

( Figs. 2A–B , 3E–F )

Host: Carassius auratus and Aristichthys nobilis .

Location: Gills.

Prevalence: Out of 12 Carassius auratus examined, one was infected (8.3 %); and out of 28 Aristichthys nobilis examined, one was infected (3.6%).

Locality: Chongqing, China (29º5' N, 106º5' E) .

Date of sampling: April, 2004 and April, 2005.

Description. Population from Carassius auratus .

Medium with thick body and body size 37.0 – 55.0µm (42.3 ± 4.1) in diameter; adhesive disc 29.0 – 45.0µm (36.3 ± 3.4) in diameter; border membrane 3.0 – 5.0µm (4.1 ± 0.7) wide; number of radial pins per denticle 8 – 10 (n = 22); diameter of denticle ring 16.0 – 28.0µm (20.8 ± 2.8); number of denticles 19 – 26 (n = 22); length of denticle 5.0 – 7.0µm (6.4 ± 0.7); span of denticle 10.0 – 15.0µm (12.8 ± 2.3); blade broad, 5.0 – 6.0µm (5.6 ± 0.3) in length; width of central part 1.5 – 2.5µm (2.1 ± 0.3) and length of ray 3.5 – 6.0µm (4.8 ± 1.4). Macronucleus horseshoe-shaped, external diameter about 28, interal diameter about 19. Micronucleus oval, situated in +Y position. Adoral ciliary spiral turns about 390º– 410º.

Population from Aristichthys nobilis

Medium with thick body and body size 37.0 – 43.0µm (40.0 ± 2.2) in diameter; adhesive disc 29.0 – 35.0µm (31.2 ± 2.4) in diameter; border membrane 4.0 – 5.0µm (4.1 ± 0.7) wide; number of radial pins per denticle 9 – 10 (n = 12); diameter of denticle ring 17.0 – 20.0µm (18.2 ± 1.3); number of denticles 20 – 22 (n = 12); length of denticle 5.0 – 6.0µm (5.2 ± 0.4); span of denticle 10.0 – 12.0µm (10.6 ± 0.9); blade 4.0 – 5.0µm (4.5 ± 0.5) in length; width of central part 1.5 – 2.5µm (1.9 ± 0.3) and length of ray 3.5 – 5.0µm (4.2 ± 0.6). Adoral ciliary spiral turns about 390º– 400º.

Description of denticle ( Figs. 3E–F ): Blade broad and distal blade surface smooth, higher than tangent point and parallel to border membrane. Anterior and posterior surface nearly parallel to each other, and anterior surface always extending beyond Y+1 axis. Ray relatively straight, parallel to or at the same line as Y axis. Apophysis of ray present. Ratio between denticle above and denticle below X axis about one.

Remarks. Trichodina kazubski was first described from the skin, fins and gills of Barbus paludinosus and B. trimaculatus from different river systems in South Africa, whereas our specimens were from Carassius auratus and Aristichthys nobilis in Chongqing, China. T. kazubski can easily be distinguished from any other species on the basis of its smaller body dimensions and differences in denticle shape, because the blade is relatively larger and much broader in appearance. Both of our populations, from Carassius auratus and Aristichthys nobilis , conform closely with the description of the body size and denticle morphology provided by Van As & Basson (1989).

T. kazubski was first collected from various indigenous African host species belonging to the family Cyrpinidae and also occurred in water systems free from the influence of introduced fish in southern African. However, it has been reported in Asia in this research, also from cyprinid hosts. This first report in Asia for T. kazubski extends its known geographic and host range, but underlines its specificity to cyprinids.

Figures

FIGURE 2. Photomicrographs of silver impregnated adhesive discs of Trichodina spp. A–B. Trichodina kazubski Van As & Basson, 1989; C–D: Trichodina mutabilis Kazubski & Migala, 1968. Scale bar = 20m.

FIGURE 3. Diagrammatic drawing of the denticles of Trichodina spp. A–B. Trichodina subtilihamata sp. nov.; C: Trichodina uniforma Van As & Basson, 1989; D: Trichodina nigra Lom, 1960; E–F: Trichodina kazubski Van As & Basson, 1989; G–H: Trichodina mutabilis Kazubski & Migala, 1968.