NEIHPID

Leipercotyle meghalayensis (Roy et Tandon Roy et Tandon) Back

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Taxonomy

Platyhelminthes »
       TREMATODA »
              Digenea »
                     Paramphistomidae Fischoeder, 1901 »
                            Orthocoeliinae Price et McIntosh, 1953 »
                                   Leipercotyle Eduardo, 1980 »
                                           Leipercotyle meghalayensis, Roy et Tandon 1990

Host

Bos (indicus)

Habitat

Rumen

Locality

Shillong (Meghalaya)

Description

Body elongated, straight, 4.29-7.32 mm long, 1.94-2.53 mm in greatest width, ratio of body width to body length 1:2.23-1:2.84. Acetabulum sub-terminal, 0.99-1.35 mm in external diameter; ratio to body length 1:4.54-1:6.25; of streptocoelium type (sensu Näsmark, 1937); number of circular muscle units in each series are as follows : d.e.c.m. 12-18, d.i.c.m. 22-30, v.e.c.m. 11-16, v.i.c.m. 21-30, m.e.c.m. 4-8. Pharynx 0.49-0.72 mm in length, 0.63-0.76 mm in width; ratio to body length 1:8.80-1:10.87, to diameter of acetabulum 1:1.62-1:2; of calicophoron type (sensu Dinnik, 1964) in median sagittal section. Oesophagus 0.36-0.45 mm long, ratio to body length 1:12.78-1:16.19, musculature of its wall gradually thickened posteriad to form an oesophageal bulb. Caeca more or less straight, extending up to anterior level of acetabulum and terminating ventrally. Testes tandem, inter-caecal; anterior testis 0.27-0.67 mm in length, 0.31-0.76 mm in width; posterior testis 0.27-0.81 mm in length, 0.31-0.67 mm in width. Vesicula seminalis thin walled; pars musculosa coiled, well developed; pars prostatica moderately developed. Ovary 0.18-0.22 mm by 0.18-0.31 mm, post-testicular. Mehlis' gland close to ovary. Laurer's canal not crossing excretory vesicle or duct, somewhat parallel to excretory canal, opening on dorsal surface about 0.14-0.39 mm anterior to excretory pore. Uterus following median course with few loose coils through its course. Vitellaria consisting of few loose or small clusters of vitelline glands in lateral fields, extending from little behind oesophageal bifurcation to anterior level of acetabulum. Eggs 0.113-0.144 mm by 0.067-0.081 mm. Excretory vesicle dorsal to acetabulum, opening on dorsal surface. Genital pore ventral, at level of oesophageal bifurcation or little behind it; terminal genitalium surrounded by distinct muscular sucker, of cotylophoron type as defined by Näsmark (1937) due to presence of a muscular genital sucker and its complete delimitation from surrounding body tissues by a membrane; genital sucker 0.40-0.72 mm in diameter, ratio to length of pharynx 1:0.93-1:1.33, to diameter of acetabulum 1:1.62-1:2.56. Scanning electron microscopic observations of the body surface revealed the presence of three types of tegumental papillae. Those around the oral aperture and also in the vicinity of genital pore are not smooth and have cilia-like structures on their apical end. Papillae in the acetabular region are dome-shaped, smooth-surfaced elevations, usually found in small clusters of 2-6 papillae each. The tegument lining the aperture of the acetabulum also has smooth but randomly scattered papillae with finely beaded surface.

Remarks

Eduardo (1980d) created the genus Leiperocotyle in the subfamily Orthocoeliinae (Paramphistomidae) to accomodate Cotylophoron okapi Leiper, 1935 and C. congolense Baer, 1936. The genus was separated from the genus Cotylophoron by the characters, viz., the Laurer's canal not crossing the excretory vesicle or its duct, the presence of a well -developed pars musculosa, weakly developed pars prostatica and a prominent genital sucker. Two species of the genus Cotylophoron, namely, C. orientalis and C. elongatum, both with Laurer's canal not crossing the excretory vesicle or duct, as described by Harshey (1934) from goats and sheep in India, were also assigned tentatively to Leiperocotyle by Eduardo (1980d). However, these species were later considered species inquirenda by Eduardo (1980c), Since their descriptions lack histological details, necessary for generic allocation among paramphistomes. Further, while Mukherjee and Chauhan (1965) proposed the synonymy of C. ovatum with Ceylonocotyle (now Orthocoelium) Scoliocoelium, Bhattacharyulu and Pande (1969) regarded the former as species inquirenda.

A comparison of the present form with other paraphistomes species described from bovine hosts of India revealed that it cannot be identified as one of these. The relationship of Laurer's canal to the excretory system brings it close to Orthocoelium spp. (Eduardo, 1985b), which, however, lack a genital sucker. Overlooking the character of Laurer's canal not crossing the excretory duct or vesicle would place the present form in the genus Cotylophoron (Eduardo, 1985a). It resembles Cotylophoron cotylophorum (Fischoeder, 1901) Stiles et Goldberger, 1910 in several features, namely, the presence of an oesophageal bulb and a genital sucker, pharynx calicophoron type and genital atrium cotylophoron (bothsensu Näsmark, 1937). However, the points of deviation include the acetabulum which is cotylophoron type (sensu Näsmark, 1937) and the intestinal caeca which have several bends and terminate dorsally in C. cotylophoron. The material pertaining to the latter species was collected during the present survey from cattle (Bos indicus) in Shillong. An examinatin of the same also revealed that the specimens described herein are different from C. cotylophorum.

In view of the foregoing, the combination of characters like the presence of a genital sucker and Laurer's canal not crossing the excretory vesicle or duct in the present form leaves no choice but to keep it in the genus Leipercotyle, so far represented only in the African continent.

The genus includes three species to date, namely, Leiperocotyle okapi (Leiper,1935) Eduardo, 1980; L. congolense (baer, 1936) Eduardo, 1980; L. gretillati Eduardo, 1985 (a new name for Ceylonocotyle scoliocoelium var. benoiti Gretillat, 1966). The present form resembles L. okapi in possessing an oesophageal bulb, laterally extending vitellaria and cotylophoron type of terminal genitalium, but it differs from the latter in having a calicophoron type of pharynx (sensu Dinik, 1964), streptocoelium type of acetabulum (sensu Näsmark, 1937) and vitellaria in the form of a few loose or small clusters of vitelline glands; in L okapi the pharynx is paramphistomum type (sensu Näsmark, 1937), and the acetabulum cotylophoron type (sensu Näsmark, 1937) and the vitellaria are in large and dense clusters.

The present form shares the characters of terminal genitalium (i.e., cotylophoron type) with L. gretillati. However, it stands apart from L. gretillati as well as from L. congolense as these species lack an oesophageal bulb and have cotylophoron type of acetabulum (sensu Näsmark, 1937); further in L. congolense the terminal genitalium is of schistocotyle type (sensu Sey and Graber, 1979)

Thus it appears that these differences are sufficient to established the present species as distinct and valid for which the name L. meghalayaensis is proposed after the origin of the material.

Specific diagnosis

Laurer's canal not crossing excretory vesicle or duct, acetabulum of streptocoelium type (sensu Näsmark, 1937 ); pharynx of colicophoron type; oesophageal bulb present, intestinal caeca terminating ventrally; terminal genitalium cotylophoron type (sensu Näsmark, 1937 ).

Helminthological collections record

NEHU/Z - TM/2

Specimen Type

Holotype (No. IV/ZSI/ERS, 298) and one series of sagittal sections (No. IV/ZSI/ERS, 299) in Zoologic

References

Eduardo , S .L. (1980d). A new genus of Leiperocotyle, for Cotylophoron okapi Leiper, 1935 and C. congolense Baer, 1936 and redescription of C. okapi. Systematic Parasitlogy, 1: 255-263.

Leiper, R. T. (1935). Helminth parasites obtained from the okapi at post mortem. Proceedings of the Zoological Society of Zoology, part 4, 949.

Baer, J. G. (1936) Un trematode parasite de l'okapi (Cotylophoron congolense n. sp). Revue de Zoologie et de Botanique Africaines, 28, 310-316.

Harshey, K. R. (1934) On amphistome parasites of sheep and goats from Allahabad. Proceedings of the Academy of Sciences, United Provinces of Agra and Oudh, India. 4:pp 95-106

Eduardo , S .L. (1980c). Orthocoelium indonesiense, a new species of amphistome from ruminants in Indonsia. Systematic Parasitology, 1: 201-210.

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.

Eduardo ,S .L. (1985a). The taxonomy of the family  Paramphistomidae Fischoeder, 1901 with special reference to the morphology of species occurring ruminants. V. Revision of the genus Cotylophoron (Stiles& Goldberger, 1910). Systematic Parasitology.7: 3-26.

Stiles, C. W. and Goldberger, J. (1910). A study of Watsonius (n.g.) watsoni of man and of allied species of mammalian trematode worms of the superfamily Paramphistomidea. Bulletin of the Hygienic Laboratory , Public Health and Marine- Hospital Service of the United States. No.60, pp 259.

Näsmark, K. E. (1937) Revision of the trematode family Paramphistomidae. Zoologiska Bidrag fran Uppsala. 16:pp 301-565.

Grétillat, S. (1966). Notes et remarques au suget d'une collection de trématodes du Musée Royal de l'Afrique Centrale. Revue de Zoologie et de Botanique Africaines, 73, 166-185.

Dinik, J.A (1964). Paramphistomum sukumum sp. nov. and other stomach-flukes from cattle in the Sukumaland area of the lake region, Tanganyika. Parasitology, 54 : 201-209.

Sey, O. and Graber, M (1979). Examination of amphistomes (Trematoda : Paramphistomidae ) of some African mammals. Revue d'Elevage et de Medecine Veterinaire des Pays Tropicaux, 32, 161-167.