North-East India Helminth Parasite Information Database

Lytocestus heteropneustii Back


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                                   Lytocestus Cohn, 1908 »
                                           Lytocestus heteropneustii


Heteropneustes (fossilis)(Bloch)




Guwahati (Assam), Shella (Meghalaya)


Body elongate, flat, with no trace of internal or external segmentation, tapering anteriorly, broader posteriorly; body proper divided into cortex and medulla by two layers of longitudinal muscles. Scolex undifferentiated, smooth, unarmed, base conical, bluntly tapering extremity followed by short neck. Testes numerous (235-340 in number), ovoid, larger than vitelline follicles, medullary in distribution, commencing little behind anterior vitellaria, extending till near ovarian lobes; cirrus sac prominent, occupying entire thickness of medulla, opening separately a little in front of the utero-vaginal pore; external seminal vesicle absent. Ovary bilobed, follicular, H-shaped, ovarian lobes joined to each other by ovarian isthmus, extending behind Mehlis’ gland posteriorly; uterus glandular, extending from in front of isthmus anteriad beyond lateral horns of ovary, no uterine coils behind ovarian isthmus; vagina distinct, joining terminal end of uterus to open unitedly at utero-vaginal pore. Vitelline follicles ovoid or spherical, cortical in disposition, strewn in mid-field of testicular region, commencing from base of neck up to anterior horns of ovary. Excretory pore terminal. Eggs 0.03 -0.04 x 0.02- 0.05 mm in size, smooth, ovoid, operculate.


In having a somewhat stumpy and stout body, the present form differs from the slender and/or long-necked L. filiformis, L. javanicus, L. lativitellarium, L. attenuatus and L. assamensis. In lacking a holdfast distinct from the neck, the present form stands apart from L. indicus and L. birmanicus. In both L. puylaerti and L. marcusenii the vitellaria are arranged in an annular manner and not intermingling with the testicular follicles as in the present form. On comparison with L. fossilis, the only other species of the genus described from the same host, i.e., H. fossilis, the present form distinctly differs in the absence of postovarian yolk glands. Even if the genus Lucknowia is considered a valid genus and not a synonym of Lytocestus, the species Lucknowia fossilis Gupta, 1961 (described from the same host) also differs from the present form in the extension of vitellaria up to the postovarian region and posterior end.

In view of the above differences, the present form is regarded as a new species of th genus.

Specific diagnosis

Body elongate, short neck, undifferentiated scolex; H-shaped ovary, testes medullary, vitellaria strewn in mid-field of testicular zone; eggs oval, smooth-surfaced, operculate.


Named after the generic name of the host.

Helminthological collections record


Specimen Type

Holotype: IV/ERS 295; Paratype: IV/ERS 296: T. S. series IV/ERS 297


Gupta, S.P. (1961) Caryophyllaeids (Cestoda) from fresh water fishes of India. Proceedings of the Helminthological Society of Washington. 28, 38-50.