Stomatocystis indica, Bandyopadhyay & Mitra & Göçmen, 2006

Bandyopadhyay, Probir K., Mitra, Amlan Kumar & Göçmen, Bayram, 2006, A new endoparasitic gregarine genus, Stomatocystis indica gen. nov., sp. nov. (Apicomplexa: Sporozoea: Stomatophorinae) from the seminal vesicles of an Indian earthworm (Annelida: Oligochaeta) Amynthas diffringens Baird, Zootaxa 1191, pp. 61-68 : 63-65

Stomatocystis indica gen. nov., sp. nov.

( Figs. 1–9 , Table 1 )

Thirty two specimens were examined. Body length (BL) 44.0–96.0 µm (70.5 ± 1.1 µm); Body width (BW) 29.0–59.0 µm (44.0 ± 1.2 µm); Nucleus length (NL) 11.5–20.0 µm (17.0 ± 1.1 µm); Nucleus width (NW) 9.5–15.0 µm (13.0 ± 1.2 µm); Stomata diameter (StD) 22.0–41.0 µm (31.0 ± 1.2 µm); Gametocyst diameter (GD) 72.0–102.0 µm (90.0 ± 1.9 µm); Oocyst length (OL) 7.9–11.0 µm (9.0 ± 1.1 µm); Oocyst width (OW) 3.0–4.0 µm (3.7 ± 1.1 µm); BL/BW 1.6:1; BW/StD 1.4:1; NL/NW 1.3:1; OL/OW 2.4:1

Mature gamonts oblong in shape having a round epimerite at the anterior end, narrowing gradually to a round posterior end. Anterior epimeritic structure contains in its centre a crater­like sucker having a rim projected slightly outside. The epimerite­ like structure is almost round to elliptical in shape having six to eight shallow indentations on the periphery progressing slightly towards the centre and very prominent in the young individuals. In mature gamonts the epimerite­like structure is discernible only in certain angle of distortion.

A sucker is present in the centre of the epimeritic structure. The sucker is broadly funnel­shaped with a truncated broad base having a roundish stomata at the external margin lodged on the surface of the epimeritic structure on a band­like protoplasmic collar. Inside the collar arise longitudinal parallel protoplasmic ridge­like processes, 8.3–10.5 µm in length, spaced 1.1–1.6 µm apart, and adhered to the inner margin of the collar. Ectoplasm is thin, without any external processes. Sarcoplasm and myoplasm layers are not very distinct.

Endoplasm is granular, without any inclusions. Only a few haematoxylin positive granules are seen accumulated in the endoplasm. The vesicular nucleus is spheroidal to ellipsoidal in shape and placed generally in the posterior part of the gamont. But in young specimens, it may be placed anteriorly. Karyosome is located near the periphery of the nucleus resulting in the formation of a vacuole at the centre.

Taxonomic summary

Type material: Stomatocystis indica gen. nov., sp. nov.

Type host: Amynthas diffringens Baird

Symbiotype: Host AD/ NG/03/2001 deposited in the Museum of the Department of Zoology, University of Kalyani, Kalyani 741235, West Bengal, India.

Type locality: East Midnapore , West. Bengal, India

Prevalance: 9 out of 23 (39%).

Number of specimens measured: 32

Type material: Holotype, slide NG/01/2001, and Paratypes, slides NG/02/2001, NG/ 05/2001, NG/07/2001 are in the collection of the Parasitology Laboratory, Department of Zoology, University of Kalyani, Kalyani 741235, West Bengal, India.

Etymology: This species was named after the motherland, India.

Site of infection: Seminal vesicles.

Figures

FIGURES 1–5. Photomicrographs of different stages in the life cycle of Stomatocystis indica gen. nov, sp. nov. from seminal vesicles of earthworm Amynthas diffringens Baird. 1. a slightly curved trophozoite showing the sucker and epimerite­like structure; 2. enlarged view of the sucker showing protoplasmic ridge­like processes in its lateral margin; 3. syzygy; 4. gametocytes within a gametocyst; 5. navicular oocysts. Abbreviation: pr­protoplasmic ridges. Scale bars: Figs. 1–4 (50 µm), Fig. 5 (10 µm)

FIGURES 6–9. Camera lucida drawings of different stages in the life cycle of Stomatocystis indica gen. nov., sp. nov. from seminal vesicles of earthworm Amynthas diffringens Baird. 6. a mature gamont showing central mucron within the sucker; 7. syzygy; 8. gametocytes within a gametocyst; 9. oocyst. Abbreviation: pr­protoplasmic ridges. Scale bars: Figs. 7–8 (50 µm), Fig. 9 (10 µm)