North-East India Helminth Parasite Information Database

Orthocoelium dawesi (Yamaguti Yamaguti) Gupta 1958 Back


Platyhelminthes »
       TREMATODA »
              Digenea »
                     Paramphistomidae Fischoeder, 1901 »
                            Orthocoeliinae Price et McIntosh, 1953 »
                                   Orthocoelium (Stiles et Goldberger, 1910) Price et McIntosh, 1953 »
                                           Orthocoelium dawesi (Gupta 1958), Yamaguti 1971


(Ceylonocotyle dawesi Gupta, 1958)


Bos (indicus), Capra (hircus), Ovis (aries)




Agartala (Tripura), Dimapur (Nagaland), Kohima (Nagaland), Aizawl (Mizoram), Tura (Meghalaya), Shillong (Meghalaya), Guwahati (Assam), Karimganj (Assam), Silchar (Assam)


Body elongated, 3.02-6.05 mm in length, 1.67-2.44 mm in width, ratio of body width to body length 1:1.76 -1:2.48. Acetabulum sub-terminal or ventral, 0.54-1.03 mm in external diameter; ratio to body length 1:4.31-1:6.01; of streptocoelium type (sensu Näsmark, 1937) in median sagittal section; units of circular muscles on lateral sides as follows: d.e.c.m. 9-14, d.i.c.m. 20-26, v.e.c.m. 10-17, v.i.c.m. 19-26, m.e.c.m. 5-10. Pharynx 0.45-0.72 mm in length, 0.36-0.58 mm in width; ratio to body length 1:6.16-1:8.40 to diameter of acetabulum 1:1.10-1:1.47; of dicranocoelium type (sensu Näsmark, 1937) in median sagittal section. Oesophagus 0.40-0.85 mm long, musculature of its wall forming a thick muscular bulb. Caeca more or less straight, reaching to anterior level of acetabulum. Testes directly tandem; anterior testis 0.72-0.90 mm in length, 0.90-1.76 mm in width; posterior testis 0.76-1.08 mm in length 0.85-1.67 mm in width. Seminal vesicle thin walled, coiled; pars musculosa well developed. Ovary 0.18-0.36 mm by 0.22-0.58 mm, posterior to testes, close to Mehlis' gland. Laurer's canal not crossing excretory vesicle or duct, opening on dorsal surface 0.22-0.36 mm anterior to excretory vesicle. Vitellaria in lateral fields, extending from oesophageal bifurcation to anterior level of acetabulum. Eggs 0.113-0.144 mm by 0.058-0.076 mm. Terminal genitalium of dawesi type (sensu Eduardo, 1985) in median sagittal section; genital pore opening at level of oesophageal bifurcation, or little behind it.


O. dawesi has earlier been reported in Calicut and Madras, (1977). This is the first record of the species from North-East India. The present observations tally with those of Gupta and Nakhasi (1977) and Eduardo, (1985b) in major features. However, minor differences were recorded in measurements of different body organs and the number of acetabular muscle units. This species was listed as a synonym of Ceylonocotyle scoliocoelium by Mehra (1980).

Helminthological collections record

NEHU/Z - TM/14

Specimen Type

Holotype: W7771/1 in Zoological Survey of India, Kolkata.


Gupta, N. K. and Nakhasi, U. (1977). On some amphistomid parasites from India (Parts I & II). Revista Iberica de Parasitologia. 37:pp  205-225, 252-272.

Eduardo ,S .L. (1985b). The taxonomy of the family  Paramphistomidae Fischoeder, 1901 with special reference to the morphology of species occurring ruminants. VI. Revision of the genus Orthocoelium (Stiles& Goldberger, 1910) Price &McIntosh, 1953. Systematic Parasitology.7:pp 125-158.

Mehra, H. R. (1980). The fauna of India and the adjacent countries. Edited by the Director, Zoological Survey of India. pp 418.