Spermiogenesis of the monozoic cestode Khawia armeniaca (Cholodkovski, 1915), a parasite of Capoeta capoeta sevangi (De Filippi, 1865) (Pisces: Cyprinidae), has been investigated by means of transmission electron microscopy for the first time. The present results show that the type of spermiogenesis in K. armeniaca shares the main features described previously in the pseudophyllideans and/or spathebothriideans: apical dense material in the zone of differentiation in the early stages of spermiogenesis, rotation of flagellum and flagellar bud, proximodistal fusion, and penetration of the nucleus into the spermatid body after the fusion of the free flagellum with the MCP has started. However, only one axoneme and a simple intercentriolar body represent presumably more evolved characters, typical for "higher" tapeworms. Ultrastructural data of spermiogenesis in K. armeniaca may support the hypothesis that the Caryophyllidea are secondarily derived from an ancestor closely allied with the Pseudophyllidea.

• MeSH
• Cestoda fyziologie   MeSH
• spermatogeneze fyziologie   MeSH
• spermie fyziologie   ultrastruktura   MeSH
• testis fyziologie   ultrastruktura   MeSH
• transmisní elektronová mikroskopie MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Spermiogenesis and ultrastructure of the spermatozoon of the pseudophyllidean cestode Triaenophorus nodulosus (Pallas, 1781), a parasite of pike Esox lucius, has been studied by transmission electron microscopy. Spermiogenesis involves firstly the formation of a zone of differentiation with two centrioles associated with striated roots, and an intercentriolar body between them, subsequent growth of the two flagella of unequal length, and a formation of a median cytoplasmic process exhibiting patches of dense material. The nucleus penetrates into spermatid body after flagellar rotation and proximo-distal fusion has started. The mature spermatozoon of T. nodulosus is filiform and contains two axonemes of 9+"1" pattern of the Trepaxonemata, nucleus, cortical microtubules parallel to the spermatozoon axis, and electron-dense granules. The anterior extremity of the gamete contains a single centriole surrounded by numerous electron-dense tubular structures exhibiting spiral arrangement and giving rise to lateral projections, which correspond to the crested body. When the crested body disappears, the spiral pattern of electron-dense tubular structures is changed into a ring, persisting until the centriole of the second axonemes appears. This structure of the crested body of T. nodulosus is unique among the Eucestoda.

• MeSH
• biologické modely MeSH
• buněčné jádro ultrastruktura   MeSH
• centrioly ultrastruktura   MeSH
• Cestoda fyziologie   MeSH
• cytoplazma ultrastruktura   MeSH
• flagella ultrastruktura   MeSH
• mikrotubuly ultrastruktura   MeSH
• morfogeneze fyziologie   MeSH
• organely ultrastruktura   MeSH
• spermatogeneze fyziologie   MeSH
• spermie ultrastruktura   MeSH
• transmisní elektronová mikroskopie MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The fine structure of the mature spermatozoon of the corallobothriine tapeworm Corallobothrium solidum Fritsch, 1886 (Cestoda: Proteocephalidea) from the electric catfish Malapterurus electricus from the Nile River in Egypt was studied by transmission electron microscopy for the first time. The filiform spermatozoon of C. solidum contains two axonemes of unequal length and a typical 9 + "1" trepaxonematan pattern. A single helicoidal crested body (30-200 nm thick) is localized at the anterior extremity of the gamete. The cortical microtubules line the periphery of the cell, largely parallel to the long axis of the spermatozoon and exhibiting signs of twisting at the beginning of region II. The nucleus, in the form of an electron-dense (largely in gametes of testes) and/or fibrous cord (largely in gametes from male reproductive ducts and seminal vesicle), coils in a spiral through the middle part (region III) of the spermatozoon. The cytoplasm contains electron-dense granules in regions II, III and partly in region IV. The cytoplasm of some spermatozoa exhibits an apparently higher electron-density at the end of the nucleated region (III), and continuously toward the middle part of region IV. The anterior and posterior extremities of the spermatozoa have a single axoneme. The ultrastructural features of the mature spermatozoon of C. solidum mostly coincide with those of the spermatozoon of other proteocephalideans, especially the gangesiine Electrotaenia malopteruri parasitizing the same host.

• MeSH
• Cestoda ultrastruktura   MeSH
• cestodózy parazitologie   veterinární   MeSH
• nemoci ryb parazitologie   MeSH
• spermie ultrastruktura   MeSH
• sumci parazitologie   MeSH
• transmisní elektronová mikroskopie MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The fine structure of the mature spermatozoon of the tapeworm Electrotaenia malopteruri (Fritsch, 1886), a member of a supposedly primitive group of proteocephalidean tapeworms (Proteocephalidae: Gangesiinae), was studied by transmission electron microscopy for the first time. The mature spermatozoon of E. malopteruri is filiform, tapers at both extremities, and contains two axonemes of 9+"1" trepaxonematan type. A helicoidal crested body (60-150 nm thick) is present at the anterior extremity of the gamete. The twisting cortical microtubules (CM) line the periphery of the spermatozoon continuously. The nucleus, a fine cord of moderately condensed chromatin, occupies the middle part (region III) of the spermatozoon. The slightly electron-dense cytoplasm contains electron-dense granules in regions II and III and becomes more electron-dense at the end of region IV. The anterior and posterior extremities of the spermatozoon contain a single axoneme. Two modes of disorganisation of the axoneme at the posterior end of the mature spermatozoa are described for the first time in cestodes. The present data also indicate that the sperm ultrastructure of E. malapteruri shows some characters typical for onchobothriid tetraphyllideans, but it resembles that of Cyclophyllidea in the arrangement of twisting of the CM.

• MeSH
• Cestoda ultrastruktura   MeSH
• cestodózy parazitologie   veterinární   MeSH
• elektronová mikroskopie MeSH
• nemoci ryb parazitologie   MeSH
• sladká voda MeSH
• spermie ultrastruktura   MeSH
• sumci parazitologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Egypt MeSH