Trichodina mutabilis Kazubski & Migala 1968

Göçmen, Bayram, 2017, First record of ectoparasitic ciliates, of genus Trichodina (Ciliophora: Trichodinidae) parasiting cultured Oranda Gold Fish (Carassius auratus auratus L.) in India, Zootaxa 4319 (1), pp. 128-142 : 132-137

Trichodina mutabilis Kazubski & Migala 1968

( Fig 3B , 4B ; Table 2)

Description. (n=14) Medium to large sized parasite. Compressed body having a diameter of 75.3–80.5 (77.9±3.6) µm. Distal surface of the denticle is flattened and straight lined simultaneously running equally to border membrane about 3.3–4.5 (3.9±0.8) µm in width and adhesive disc 40.5–55.7 (48.1±7.7) µm in diameter. Denticular ring 24.5–37.0 (30.75±8.8) µm in diameter, having a 22–26 (24±2.8) number of denticles containing 9–10(11±0.7) radial pins in each denticle. The denticle spans are 12.0–19.0 µm (15.5±4.9) in width and 5.4–8.5 µm (6.95±2.1) in length. The blade almost thickened along with posterior borders ( Figure 3b and Figure 4b ). Denticle blade is oblong with rectangular distal end having a length of 5.0–9.0 µm (7.0±2.8). Apex projected towards the y+1 axis. Blade apophysis is very prominent and with narrow central part having a diameter of about 1.5–3.9 (2.7±1.6) µm, which extends almost halfway to y-1 axis. The denticles were arranged in a tight manner. Narrow ray with blunted tip of 5.2–9 (7.1±2.6) µm long and directed towards y+1 axis. The number of radial pins 11 (9–13) per denticle present. Nuclear apparatus not observed.

Taxonomic summary

Host: Carassius auratus auratus (L.)

Locality : Haringhata, Nadia, West Bengal, India (22°53’N – 24°11’N / 88°09’E – 88°48’E)

Location: Skin and Gills

Reference material. Lectotype: In slide no. GF-TM-10/2014, deposited in the collection of the Parasitology Laboratory , Department of Zoology , University of Kalyani , Kalyani, Nadia, West Bengal, India.

Remarks. After careful consideration of the morphological characters and quantitative data, the specimen being described here has been clearly identified as Trichodina mutabilis Kazubski and Migala 1968 . T. mutabilis was firstly described by Kazubski & Migala from Poland in 1968. Since then, it has been reported from various parts of the world, including India ( Lom 1970; Basson & Van 1994; Mitra & Bandyopadhyay 2005; Dove & Donoghue 2005; Hu 2012). This is an important findings since indicated T. mutabilis also prefers ornamental fish as its host and also established as a new host for the parasite and it is the first record of this species from Carassius spp . in India. The population obtained from Carassius auratus auratus (L.) show significant resemblance in denticle structure with those of specimens reported by Lom (1970) found isolated Cyprinus carpio ( Table 2).

Description. (n=17) Large to medium sized trichodinid, with compressed disc-shaped body having 55.6–71.4 (63.5±5.1) µm in diameter, featured by a central circular space of about 8.0–11.5 (9.75±2.4) µm in diameter, which remains free from silver. The specimen with an adhesive disc of 41.5–60.9 (51.2±3.7) µm in diameter containing denticular ring measuring 25.6–37.5 (31.55±8.4) µm in diameter. It consist of 18–25 (21.5±4.9) number of denticles which is surrounded by a wide broader membrane of about 4.4–5.1 (4.75±0.4) µm diameter in width. The denticle blades are sickle-shaped having a length of 6.5–11.0 (8.75±3.1) µm and with denticle span of about 11.7– 18.9 (15.3±5.0) µm wide. Central part of the blade is triangular in shape and 8–12 (10±2.8) radial pins are found in each denticle of every specimen. The apophysis of the blade is pronouncly pointed with sharp ending having a blade length of 4.3–6.5 (5.4±1.5) since it is extended to the posterior portion of the central part. Ray mostly flattened and evenly from central part to pointed tip measuring 5.5–8.9 (7.2±2.4) long and forming a 2.1–3.5 (2.8±0.9) wide central part. Nuclear apparatus not observed.

Taxonomic summary

Host: Carassius auratus auratus (L.)

Locality : Haringhata, Nadia, West Bengal, India (22°53’N – 24°11’N / 88°09’E – 88°48’E)

Location: Skin and Gills

Reference material: Lectotype: In slide no. GF- TA-15/2014, deposited in the collection of the Parasitology Laboratory , Department of Zoology , University of Kalyani , Kalyani, Nadia, West Bengal, India

Remarks. Considering the morphological characters and quantitative data, the specimen seems to be identified as Trichodina acuta Lom (1961) . The sp. was first described by Lom in 1961 from various types of freshwater fish of Bohemia. Since the specimen showed a wide range of geographical distribution and biodiversity of hosts from various places of the world ( Kazubski & Migala 1968; Lom 1970; Dove & Donoghue 2005; Basson et al. 1983; Van & Basson 1989; Gaze & Wooten 1998). T. acuta has previously been recorded in India by Asmat (2000b) and Mitra (2013) from freshwater fish, but it is recorded for the first time as a pathogen of Carassius spp . from India. Trichodina acuta obtained in the present study apparently shows considerable morphological variability with Lom (1961). ( Table 3)

Description. (n=8) Large trichodinid with flattened body having a diameter of 52.5–59.6 µm (56.05±5.0) and surrounded by a wide border membrane 3.8–6.0 µm (4.9±1.5) in width. The adhesive disc is 44.1–48.3 (46.2±2.9) µm in diameter with a clear granule at the free center. The denticulate ring measures 27.5–33.5 µm (30.5±4.2) having a number of denticles about 25–31(28±4.24). Number of radial pins per denticle is 8–10 (9±1.4). The blade of denticle is rectangular having 5.0–7.0 µm (6.0±1.4) in length, covering almost half area of the entire spaces between y+1 axis (Figure 6a and Figure 6b). Span of denticle is 14.2–16.5 (15.35±1.6) µm and having a length of 5.1–7.2 (6.15±1.4) µm. The apical ejection is well developed and never impregnated. The blade connection contains well developed smooth surface which mostly parallel to the anterior blade surface. The central part fits tightly into the preceding denticle with rounded point that extends almost halfway to y-1 axis, Width of the central part is 2.5–3.1 (2.8±0.4) µm. Ray relatively narrow and measures 5.8–8.0 (6.9±1.5) µm.

Taxonomic summary

Host: Carassius auratus auratus (L.)

Locality : Haringhata, Nadia, West Bengal, India (22°53’N – 24°11’N / 88°09’E – 88°48’E)

Location: Gills

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

Remarks. After considering the morphological features and quantitative data of the present material it was very clearly identified as Trichodina ngoma Van & Basson (1992). It was firstly reported from Hemigrammocharax multifasciatus of Lake Lisikili, belonging to the Zambesi River System, which locates in Eastern Caprivi, South Africa by Van & Basson in 1992. After that it was reported from China by Tang & Zhao (2010). Till date it has not been reported again from India. The study will throw light on biodiversity and host preference of the species and also regarding new distribution in Asian subcontinent. The dimensions of the present specimen are showing close similarities to those reported in China by Tang & Zhao (2010) ( Table 4).

Species Trichodina ngoma Trichodina ngoma Host Carassius auratus auratus Carassius auratus

Figures

FIGURE 3. A – F Photomicrographs of silver nitrate impregnated adhesive discs of Trichodinid species. (A) Trichodina reticulata Hirschman & Partesh 1955 (B) Trichodina mutabilis Kazubski & Migala 1968 (C) Trichodina acuta Lom 1961 (D) Trichodina ngoma Van & Basson 1992 (E) Trichodina nandusi Mitra et al. 2013 (F) Trichodina domergui Wallengren 1897 identified from Carassius auratus auratus (L.). Scale Bar – 20 µm.

FIGURE 4. A – F Diagrammatic drawings of the denticles of Trichodinid species i. e. (A) Trichodina reticulata Hirschman and Partesh 1955 (B) Trichodina mutabilis Kazubski & Migala 1968 (C) Trichodina acuta Lom 1961 (D) Trichodina ngoma Van & Basson 1992 (E) Trichodina nandusi Mitra et al. 2013 (F) Trichodina domergui Wallengren 1897 obtain in the present study.