Tripartiella macrosoma Basson & Van As , 1987

Tang, Fahui, Zhao, Yuanjun & Liu, Chunning, 2013, First records of three Tripartiella species (Ciliophora, Oligohymenophora, Peritrichida) from freshwater fishes along Yangtze River in China, Zootaxa 3681 (2), pp. 169-174 : 172-173

Tripartiella macrosoma Basson & Van As, 1987

Host: Rhinogobio typus

Locality: Qu County, Sichuan Site: Gills

Date of sampling: April, 2012 Description ( Figs. 5, 6 , 9 ). The following morphological description was based on 20 specimens measured (n = 20). Small freshwate r Tripartiella with a compressed body, diameter 19.0–26.0 (23.1 ± 1.6); adhesive disc 14.0– 23.0 (18.0 ± 2.3); width of border membrane 1.5–3.0 (1.9 ± 0.4); diameter of denticle ring 8.0–10.0 (9.3 ± 1.1); number of denticles 23–27; number of radial pins per denticle usually 4–5; span of denticle 5.5–7.0 (6.4 ± 0.5); length of denticle 2.0–2.5 (2.1 ± 0.1); blade long-strip or long-spoon shaped, length 4.0–5.5 (4.6 ± 0.4), and pointed backward; distal blade surface rounded, not in parallel with border membrane, and much higher than the tangent point; anterior and posterior surfaces rough, not parallel with each other; anterior surface blade apophysis indistinct, just touching the Y +1 axis; blade apophysis dominant and extending past Y +1 axis. Central part relatively thin with point fitting tightly into preceding denticle. Shapes of the central part above and below the Xaxis not symmetrical and 0.5–1.5 (0.9 ± 0.2) in width. Ray connection barely distinguishable from the ray. Ray slim, and short, 1–2.0 (1.7 ± 0.2) in length, ray apophysis invisible; ratio between denticle above and below X axis much more than two. Macronucleus C-shaped, external diameter 17.5–23.5 (19.8 ± 1.5) and internal diameter 12.5–19.0 (15.8 ± 1.6). Micronucleus oval, 1.0–2.0 (1.4 ± 0.4) in length and 0.5–1.5 (0.8 ± 0.2) in width, situated in Y position. Adoral ciliary spiral turns about 190°– 230° around peristomial disc.

Remarks. Tripartiella macrosoma was originally described from gills of Barbus eutaenia in Klein Letaba River of the Olifants River system, South Africa ( Basson & Van As, 1987). Later, it was first reported from gills of freshwater fishes, Hypophthalmichthys molitrix , Ctenopharyngodon idella and Pelteobagrus vachellii in Chongqing and Ningbo area of China ( Tao & Zhao, 2006; Yu et al., 2011). The present population was isolated from gills of another freshwater fish, Rhinogobio typus , in Sichuan area of China. The morphology of adhesive disc of the present population is in agreement with the original description and morphometric data are also well within the range of the original description. Rhinogobio typus is established as the new host record for Tripartiella macrosoma in the present research work.

Figures

FIGURES 1 – 6. Photomicrographs of silver impregnated adhesive disc of Tripartiella species. 1 - 2. Tripartiella obtusa Ergens & Lom, 1970; 3 - 4. Tripartiella orthodens Basson & Van As, 1987; 5 - 6. Tripartiella macrosoma Basson & Van As, 1987. (Scale bars = 20 µm).

FIGURES 7 – 9. Diagramatic drawings of the denticles of three Tripartiella species. 7. Tripartiella obtusa Ergens & Lom, 1970; 8. Tripartiella orthodens Basson & Van As, 1987; 9 Tripartiella macrosoma Basson & Van As, 1987.