Taxonomical studies of four new Aseptate Gregarine parasites belonging to the Genus Monocystis Stein, 1848 (Protozoa: Apicomplexa: Sporozoa) from an Oligochaete Host, Eutyphoeus orientalis (Annelida: Oligochaeta) of West Bengal, India Author Sarkar, Sutapa Author Kundu, Beauty Author Bandyopadhyay, Probir K. text Records of the Zoological Survey of India 2019 119 4 journal volume 10.26515/rzsi/v119/i4/2019/142223 2581-8686 13185663 Monocystis eutyphae sp. nov. Figures 1 (A-D), 2(AD) Table A & Table 1 Description In Monocystis eutyphae sp. nov. gamonts are fusiform, anterior portion is wider than the posterior end. The anterior end contains mucron. Nucleus is rounded, situated in the middle portion of the body. The pellicle is thin. Presence of highly granulated endosarc contains paraglycogen granules. Gametocyst ovoid with two unequal gametocytes. Oocysts are biconical. Gamont measures 100.7 - 107.8 (104.83 ± 2.02) µm in length and width of the anterior part of gamont is 51.93 - 59.67 (55.68±3.13) µm and Posterior part is 20.99-23.86 (22.69 ± 1.08) µm. Diameter of nucleus is 10.5-11.0 (9.0 ± 1.05). Gametocyst measures 89.50-96.13(93.04 ± 2.81) µm in length and 67.40 - 78.45(72.37 ± 4.35) µm in width. Length of the oocyst measuring 13.25-15.47(14.30 ± 0.91) µm and width measuring 9.94-13.26 (11.70 ± 1.40) µm. Figure 2. Monocystis eutyphae sp. nov. (camera lucida drawings of different stages of life cycle) A. Trophozoite. B. Syzygy. C. Gametocyst. D . Oocyst. Scales: A-C = 100µm; D=10µm. Figure 1. Photomicrographs of different stages of the life history of Monocystis eutyphae sp. nov. obtained from the seminal vesicles of earthworm Eutyphoeus orientalis , A. Trophozoite (Black arrow - mucron); (white arrow - granulated endosarc). B. Syzygy. C. Gametocyst. D. Oocyst. Scales: A - C = 100µm; D = 10µm Taxonomic Summary Type host : Eutyphoeus orientalis . Site of infection : Seminal vesicles. Type locality : Ashoknagar, North 24 Parganas ( 23º15’2’’ N- 89º5’E ), West Bengal , India . Prevalence : 20 out of 40 host earthworms (50%) were infested with the parasite. Material deposited Holotype : PR/ MC/01 /12 has been deposited at the Parasitology Laboratory , Department of Zoology , University of Kalyani 741235, and West Bengal , India . Paratype : The paratype has been deposited in the Harold W Manter , Laboratory of Parasitology , Systematic Research Collections, University of Nebraska State Museum, W 436, Nebraska Hall, Lincoln, Nebraska 68588-0514 USA ,(Accession no. P-2014-002; Reg.no. HWML 49901 ) . Etymology : The species name has been derived from the generic name of the host specimen, Eutyphoeus orientalis . Table A. Summary of morphometric data (±µm) of the observed Monocystis eutyphae sp. nov. stages in the seminal vesicles of Eutyphoeus orientalis
Parameters Range Mean Median SD SE CV%
Length of the trophozoite 100.7-107.8 104.83 104.39 2.02 0.45 1.92
Width of the trophozoite 51.93-59.67 55.68 55.23 3.13 0.69 5.62
Diameter of the nucleus 10.5-11.0 9.0 9.25 1.05 0.23 11.66
Length of the gametocyst 89.50-96.13 93.04 93.0 2.81 0.62 3.02
Width of the gametocyst 67.40-78.45 72.37 72.01 4.35 0.97 6.01
Length of the oocyst 13.25-15.47 14.30 14.02 0.91 0.20 6.36
Width of the oocyst 9.94-13.26 11.70 11.30 1.40 0.31 11.96
Table 1. The morphometric comparisons of Monocystis eutyphae sp. nov. (Present work) with M. lalbagensis and M. nadiensis
Species characters Monocysts lalbagensis (Bandyopadhyay et.al., 2001) Monocystis nadiensis (Bandyopadhyay et.al ., 2002) Monocystis eutyphae sp. nov. (present work)
Host Metaphire posthuma Metaphire posthuma Eutyphoeus orientalis
Locality Lalbag, Murshidabad, India Fulia, Nadia, West Bengal, India Ashoknagar, 24 parganas (N), W.B., India
Site of infection Seminal vesicles Seminal vesicles Seminal vesicles
Trophozoite Cone shaped. Pellicle distinct, very delicate, length measures 62.4-108.1 µm and width measures 33.2 -53.2µm. Ballon shaped, measuring 110.7-132.12µm x 74.99- 85.70µm. Fusiform, anterior part wide and posterior part is blunt. Total length 100.7-107.8 (104.83±2.02) µm. anterior portion width is 51.93-59.67 (55.68±3.13) µm and posterior portion width is 20.99-23.86 (22.69±1.08)µm.
Ectosarc Not stated Smooth Smooth and irregular
Endosarc Vacuoles excavated the endoplasm Densely granulated Granulated with paraglycogen granules
Nucleus Spherical, measures 8.3 – 12.5 µm in diameter with an average of 9.3 Rounded, measures 10.7-14.2 (13.05±1.59)µm Rounded, measures 10.5-11.0 (9.0±1.05) µm in diameter
Gametocyst Ovoidal contains two unequal gametocytes. Larger one measuring 71.0-83.2 µm x 45.0-76.1µm and smaller one measuring, 58.2-75.0 x 32.1-50.0µm. Ovoidal possess two unequal gametocytes. Larger one measuring 99.98-117.84 µm x 74.99-99.98µm and smaller one measuring 82.13- 96.41µm x 74.99-82.33µm. Ovoidal having two uneual gametocytes. It measures 89.50- 96.3 (93.04±2.81) µm x 67.40-78.45 (72.37±4.35)µm.
Oocyst Biconical, measuring 6.4-6.6 µm x 3.1-3.3µm in diameter. Biconical, measures 8.3- 9.7µm x 4.1-5.5µm in diameter. Biconical, length measures13.26-15.47 (14.30-0.91) µm and width measures 9.94-13.26(11.70±1.40) µm.
Remark The species under discussion shows similarities and dissimilarities with Monocystis lalbagensis and Monocystis nadiensis respectively. The present species differs from M. Lalbagensis relating its shape and size of the body. Trophozoites are cone shaped in M. lalbagensis , while they are balloon shaped in M. nadiensis and fusiform in M eutyphae sp. nov. In M. lalbagensis vacuoles excavate the endosarc whereas, in M. nadiensis , cytoplasm is densely granulated as like as that of present species. The anterior end of present species is wider than the posterior end which looks like blunt shaped. A big ovoidal distinct mucron is present in the anterior portion. The nucleus is rounded, present near the mucron at anterior portion of the body. Pellicle is thin. In the present form syzygy stage is present in the life cycle, while this stage is absent in the earlier described species. The position, shape and size of the nucleus, gametocyst and oocyst, host and the geographic location of the present species differ from the earlier described species ( Table 1 ). Taking into consideration all the differences with the closely related species, the present species seems to be new to science. Hence the name Monocystis eutyphae sp. nov. is being proposed here.