Trichodina bellottii, Marcotegui & Montes & Barneche & Ferrari & Martorelli, 2018

Marcotegui, Paula S., Montes, Martin M., Barneche, Jorge, Ferrari, Walter & Martorelli, Sergio, 2018, Geometric morphometric on a new species of Trichodinidae. A tool to discriminate trichodinid species combined with traditional morphology and molecular analysis, International Journal for Parasitology: Parasites and Wildlife 7 (2), pp. 228-236 : 230

Trichodina bellottii n. sp. ( Fig. 1 : A-F, Fig. 2 : A-B).

All measurements were done on 20 specimens. Medium sized freshwater Trichodina , body diameter 67.57 ± 4.03; diameter of adhesive disc 57.342 ± 4.93; width of border membrane 4.99 ± 0.88; diameter of denticle ring 36.10 ± 3,15; number of denticles 21–26 (23); number of radial pins per denticle 11–12 (11); span of denticle 18.20 ± 1.5; length of denticle 8.02 ± 0.77; blade broad and sickle-shaped, length 5.09 ± 0.66, distal blade surface smooth and a little curved, not in parallel with border membrane; tangent point small, rounded, situated only slightly below distal surface; some specimens with a notch on the proximal anterior margin; apex present beyond Y +1 axes; anterior and posterior surfaces curved and did not parallel with each other; blade apophysis visible in some specimens; deepest point of blade posterior surface at the same level of apex. Blade connection thick and posterior projection present, encasing in an indentation of posterior denticle. Central part very developed extending half way to Y-1 axis, some specimens fit irregularly into preceding denticle, others specimens with a rounded point fitting into preceding denticle. Central part 3.69 ± 0.45 in width, and the shape of central part above and below the X-axis is dissimilar. Indentation on lower central part. Ray connection well developed. Ray robust and relatively long, slightly curved to Y-1 axis, and tapers to a rounded point; ray apophysis present, length of ray 8.511 ± 1.21. Ratio between denticle above and below X-axis different to one. Macronucleus horse-shoe shaped, length 50.83 ± 0.54; distal ends 24.8 ± 0.62. Adoral ciliary spiral turns about 380̊–410̊ around peristomial disc.

Figures

Fig. 1. Microphotographs of Trichodina bellottii n. sp. from Austrolebias bellottii. (A–D) Adhesive disc after dry silver impregnation. E) Ciliature. (F) Macronucleus with methylene-blue staining. Scale bars: 20 μm.

Fig. 2. Diagrammatic drawings of denticles of trichodinids. (A and B) Denticle of Trichodina bellotti n. sp. from Austrolebias bellottii. (C) Trichodina hypsilepis redrawn from Wellborn (1967). (D) Trichodina heterodentata redrawn from Duncan (1977). (E) Trichodina paraheterodentata redrawn from Tang and Zhao (2013). (F) Trichodina pseudoheterodentata redrawn from Tang et al. (2017).