Trichodinella epizootica ( Raabe, 1950 ) Šramek-Hušek, 1953

Saha, Mandira & Bandyopadhyay, P. K., 2016, First report of some known Trichodinella epizootica Šramek-Hušek, 1953, and Tripartiella Lom, 1959 from the cultured Oranda Gold Fish (Carassius auratus auratus) in India, Zootaxa 4184 (1), pp. 130-140 : 132-134

Trichodinella epizootica ( Raabe, 1950) Šramek-Hušek, 1953

( Fig. 1 ; Table 2 )

Description (Number of specimens measured—53). A small trichodinid with a disc-shaped body, diameter 17.6– 22.4 (20.0±3.3); adhesive disc concave and 13.5–19.6 (16.55±4.3) in diameter, Border membrane narrow, but distinct with fine striations with 1.4–1.9 (1.65±0.3) wide. Blade elongated with almost parallel margins and tapering to the portion of the anterior projection with denticular ring diameter 7.1–9.6 (8.35±1.7). Distal margin closely adjoining border membrane truncated or slightly bent with blunt tangent point which forms a small line with y-1- axis, situated lower than the distal margin ( Fig. 1 E). Anterior margin runs at slight angle to y-axes as shown in Fig. 1 F. Anterior projection slender, but prominent and fits well into the notch between central part and blade of preceding denticle. Central part rounded and pronounced touches and extends slightly beyond y axis shown in Fig. 1 F. Ray forms a short delicate hook curved along with central part 0.5–1.0 (0.75±0.3), ray 0.9–1.3 (1.1±0.2), number of radial pins per denticle 6–8 (7±1.4), number of denticles 20–22 (21±1.4), dimensions of denticle, length 1.5–2.2 (1.85±0.4), blade 2.4–3.3 (2.85±0.6), span 4.1–4.8 (4.45±0.4).

Taxonomic summary:

Host: Carassius auratus auratus (L.)

Locality : Howrah, West Bengal, India (22°35'N, 88°19'E)

Location: Gills

Reference material. Lecotype: In slide no. GF-TE-11/2014, deposited at the collection of the Parasitology Laboratory, Department of Zoology, University of Kalyani, Kalyani, Nadia, West Bengal, India.

Remarks. On analyzing the morphmetric and quantitative data of the present specimen, it was readily identified as Trichodinella epizootica Raabe (1950) . It was firstly described by Raabe (1950). The dimensions of the present material are showing huge similarities to those recorded in South Africa and Israel by Basson et al. (1983) and with Mitra & Halder (2004) in India. This finding is important because it reveals that T. epizootica also prefers the ornamental fish as its host and also established as a new host for the parasite which throws new light on the biodiversity and host preference of the species and most importantly it is the first record of this species from Carassius spp. in India as well as world. Trichodinella epizootica obtained in the present study is morphometrically compared with those described by other authors. ( Table 2 ).

Figures

FIGURE 1. (A – D) Photomicrographs of silver nitrate impregnated adhesive discs of Trichodinella epizootica (Raabe 1950) Šramek-Hušek 1953 recovered from the gills of Carassius auratus auratus (L.). (E & F) Showing the diagrammatic drawings of the denticles of the specimens. Scale bars 10 µm.

Tables

TABLE 2. Morphometric comparison of T. epizootica obtained in the present study with those of Mitra & Halder (2004) and Basson et al. (1983).

Species	Trichodinella epizootica	Trichodinella epizootica	Trichodinella epizootica
Host	Carassius auratus auratus	Puntius gelius	Cyprins carpio
Locality	Howrah,West Bengal,India	Ranaghat, India	South Africa
Site of Infection	Gills	Gills	Gills
Reference	Present study	Mitra & Halder (2004)	Basson et al. (1983)
Diameter of Body	17.6–22.4 (20.0±3.3)	17.3–23.4 (19.4±2.0)	18.2–26.5 (22.2 ± 2.2)
Adhesive disc	13.5–19.6 (16.55±4.3)	13.3–19.4 (15.8 ± 1.9)	14.4–22.5 (18.4 ± 2.0)
Dimension of body
Denticular ring	7.1–9.6 (8.35±1.7)	6.1–9.2 ((7.6 ± 0.9)	7.4–13.2 (10.3 ± 1.4)
Central area	-	-	-
Width of broader membrane	1.4–1.9 (1.65±0.3)	1.3–2.2 (1.8 ± 0.3)	1.5–2.3 (2.1 ± 0.2)
Number of denticles	20–22 (21±1.4)	17–24 (19)	20–25 (23)
Number of radial pins/Denticle	6–8 (7±1.4)	3.0–6.0 (4)	5–6 (5)
Dimension of denticle
Span	4.1–4.8 (4.45±0.4)	3.0–5.1 (4.1 ± 0.5)	-
Length	1.5–2.2 (1.85±0.4)	1.5–2.5 (2.1 ± 0.3)	1.8–2.9 (2.3 ± 0.3)
Dimension of denticle components
Length of ray	0.9–1.3 (1.1±0.2)	-	-
Length of blade	2.4–3.3 (2.85±0.6)	2.1–4.1 (3.3 ± 0.5)	1.7–3.8 (2.7 ± 0.4)
Width of central part	0.5–1.0 (0.75±0.3)	0.5–1.0 (0.9 ± 0.2)	0.7–1.2 (1.0 ± 0.2)