Myxobolus sophorae Jayasri, 1982

Garg, Anupma, Chaudhary, Anshu, Gupta, Abhishek, Kumar, Abhinav, Sharma, Bindu & Singh, Hridaya Shanker, 2020, Molecular Characterization of Two Myxosporean Species, Henneguya namae Haldar et al. 1983 and Myxobolus sophorae Jayasri, 1982 (Myxosporea: Myxobolidae), Acta Protozoologica 59 (1), pp. 39-53 : 42-46

Myxobolus sophorae Jayasri, 1982

Type host: Puntius sophore (Hamilton, 1822) ; punti (local name).

Site of infection: Kidney.

Locality: Meerut (29° 01’ N, 77° 45’ E), in the state of Uttar Pradesh (U.P.), India.

Prevalence of infection: A total of 34 specimems of Puntius sophore shows prevalence of infection: 11/34 (of the 5–6 cm size in length with a prevalence of 32%; Intensity of infection: Low) during the present study.

Material deposited: Digital images (Photos) of spores were deposited in the parasitological collection of the Museum, Department of Zoology, Chaudhary Charan Singh University, Meerut (U.P.), India collection no. (Coll. No. HSS/ZOO/MYX/02/19). The 18S rDNA sequence was deposited in GenBank under accession numbers MN 595207 and MN 595208.

Description: Plasmodia filled with spores and scattered spores were found in the kidneys. Spores ovorounded shaped in frontal view, anterior and posterior ends blunt, anterior end narrower than the posterior end ( Fig. 1 E, F ; Fig. 2 C, D ). Spore length 14.0–15.1 (14.57 ± 0.33) (N = 30); width, 10.4–11.4 (10.91 ± 0.34) (N = 30) and thickness, 6.2–7.4 (6.91 ± 0.35) (N = 20). Polar capsules two in number, pyriform in shape and slightly unequal in size, obliquely located on either side of the midline, filling around half of the spore cavity. Larger capsule length 5.72–6.5 (6.04 ± 0.27) (N = 30) and width, 2.6–3.2 (2.89 ± 0.22) (N = 30). Smaller capsule length 4.94–6.14 (5.48 ± 0.34) (N = 30) and width, 2.34–3.12 (2.69 ± 0.24) (N = 30). Polar capsules open to exterior of spores on either side of midline pointing towards each other, equipped with polar filaments which are distinctly seen. Number of filament coils seen is 5–6 in both the polar capsules, polar filament threadlike and uniform in their thickness throughout the length. M. sophorae identified morphologically on the basis of above described characteristics and the details of morphometrical data of M. sophorae with other related species are presented in supplementary table 2.

Remarks: This species was originally described from the gills and kidney of P. sophore by Jaysari, 1982. Myxospores of M. sophorae differentiated from the other species that infected host of the genus Puntius from India based on morphology and morphometrics (Supplementary table 2). M. barbi Tripathi, 1952 spores show differs from M. sophorae in having equal, small sized polar capsules and a intercapsular ridge while M. saranai ( Tripathi, 1952) emend. Landsberg and Lom, 1991 spores are smaller in size and have unequal polar capsules as compare to M. sophorae . M. ampullaceus Lalita Kumari, 1969 have spores with oval, smaller sized with equal, flask shaped polar capsules and marked on posterior margin that clearly differentiates from M. sophorae . M. hyderabadense (Lalita Kumari 1969) emend. Gupta and Khera, 1988 spores differed from M. sophorae by pyriform shape, with narrow, pointed anterior end and 4–6 ridges at the posterior end with equal sized polar capsules with filament coils (8–9). Spores of M. indiae (Lalita Kumari 1969) emend. Gupta and Khera, 1988 also differed in having narrow, pointed anterior end with having 8–10 filament coils. M. koli have spores with small size, truncated anterior end in comparison to M. sophorae whereas M. osmaniae Lalita Kumari, 1969 shows marked differentiation with M. sophorae that comprises narrow, bent anterior end with 8–10 parietal folds on the posterior margin and polar capsules with prominent neck. M. pinnaurati Lalita Kumari, 1969 spores are smaller in size as compared to M. sophorae though M. karnatakae ( Hagargi and Amoji, 1981) emend. Landsberg and Lom, 1991 spores are pyriform, larger in size with equal size polar capsules, having 6–7 filament coils that differentiated it from M. sophorae . M. sophorae can be readily distinguished from M. curmucae Seenappa and Manohar, 1980 in having spores more rounded anteriorly in comparison to it. M. mathuri Jayasri et al. 1981 comprises pointed anterior end with the slightly thick posterior end having 8–9 filament coils in large capsule and 3–4 coils in a smaller capsule as compared to M. sophorae . M. filamentosus Haldar et al. 1985 differentiated from M. sophorae (by slightly unequal capsules) as equal capsules are present in M. filamentosus . Spores of M. rohitae are smaller with a triangular notch at the anterior end and equal sized polar capsules that clearly recognize it from M. sophorae . M. saranae Gupta and Khera, 1990 differed in having small size spores and unequal polar capsules from M. sophorae . Besides the above, M. sophorae differed from other species as: M. ticto Sheeja and Janardanan, 2006 display different morphology by having 6–8 sutural folds in the posterior one-third of spore with equal polar capsules; while M. puntiusi Sheeja and Janardanan, 2006 clearly discriminate in morphology from M. sophorae by comprises 12 distinct sutural folds and two unequal polar capsules. Despite sharing some morphometric similarity M. chittalii Kaur and Singh, 2011 revealed a difference from M. sophorae having spores pear shaped with characteristic nipple-like anterior end, two equal polar capsules and a tongue shaped intercapsular process is also present. Spores of M. puntiusii Gupta and Kaur, 2017 significantly differed from M. sophorae with having one large and one smaller polar capsule. So, the present collected Myxobolus species was identified as M. sophorae based on the above mentioned characters.

Molecular analysis: Our 18S rDNA sequences of M. sophorae isolates (1260 and 1268 bp) shown to be most similar to M. ticto . No intraspecific divergence was found among the newly generated sequences from isolates of M. sophorae . Genetic p-distance comparison showed a sequence divergence of M. sophorae with M. ticto is 0.07% both found from the same fish genera Puntius .

Figures

Fig. 1. Photographs of myxobolids: A – Cysts of H. namae of different sizes between gill filaments of the host fish show by arrows, B – Spores released from ruptured cysts of H. namae, C – H. namae frontal view, D – H. namae sutural view, E – M. sophorae frontal view, F – M. sophorae sutural view. Scale bars (A) 300 µm, (B) 50 µm, (C–F) 10 µm.

Fig. 2. A schematic drawing of Henneguya namae and Myxobolus sophorae myxospores found infect Chanda nama and Puntius sophore. In frontal view:A – H. namae, C – M. sophorae. In sutural view: B – H. namae, D – M. sophorae. Scale bars (A–D) 10 µm.