1 - 3 of 3
Number of results to display per page
Search Results
2. Redescription of Monorcholepis dujardini (Krabbe, 1869) and M. passerellae (Webster, 1952) (Cestoda: Cyclophyllidea: Aploparaksidae) in passerine birds from the Holarctic Region
- Creator:
- Bondarenko, Svetlana and Komisarovas, Jurijus
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Cestoda, Cyclophyllidea, Aploparaksidae, Monorcholepis, Passeriformes, and Holarctic
- Language:
- English
- Description:
- Two species of avian tapeworms, Мonorcholepis dujardini (Krabbe, 1869) and M. passerellae (Webster, 1952), of the cyclophyllidean family Aploparaksidae Mayhew, 1925 (earlier included in the Hymenolepididae) are redescribed. Relative to congeners, the morphology of the strobila of both species shows strong similarities including a unique form of the cirrus. Separation of these species, however, can be based on the number (40-53 and 25-31, respectively) and size (18-25 µm and 14-18 µm) of the rostellar hooks, although their shape in specimens of both species varies considerably. We examined specimens of Monorcholepis dujardini in Turdus iliacus L., T. philomelos Brehm and T. merula L. from the Curonian Spit (Baltic Sea, Russia), T. naumanni Temminck from Chukotka, Motacilla alba L. from the Kuril Islands (Russia) and Passerella iliaca iliaca (Merrem) from Alaska (USA). Specimens in T. iliacus from the collection of O. Fuhrmann (Natural History Museum, Geneva, Switzerland) were re-studied. The type material (holotype and paratypes) designated as M. dujardini neoarctica (Webster, 1955) in Ixoreus naevius naevius (Gmelin) from Douglas Island, USA was re-examined and validity of this subspecies was rejected. A redescription of M. passerellae (Webster, 1952) was based on material in P. iliaca iliaca from Wisconsin (type specimen), and Point Barrow, Alaska, and on the one specimen recorded for the first time, in Turdus iliacus from the Palaearctic (Curonian Spit). Species of the genus Monorcholepis Oshmarin, 1963 and subgenus Aploparaksis (Tanureria) Spassky et Yurpalova, 1968 are characterized by similar topography of the gonads. These generic taxa and the interrelationships of constituent species are discussed.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Ultrastructure of spermiogenesis and mature spermatozoon of Triaenorhina rectangula (Cestoda: Cyclophyllidea: Paruterinidae)
- Creator:
- Yoneva, Aneta, Georgieva, Katia, Nikolov, Pavel N., Mizinska, Yana, Georgiev, Boyko B., and Stoitsova, Stoyanka R.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Cestoda, Cyclophyllidea, Paruterinidae, Triaenorhina rectangula, ultrastructure, spermiogenesis, and spermatozoon
- Language:
- English
- Description:
- Ultrastructural characters of spermiogenesis and mature spermatozoon of Triaenorhina rectangula (Fuhrmann, 1908) are examined by transmission electron microscopy. Spermiogenesis follows the Bâ and Marchand's Type III spermiogenesis of cestodes. The process begins with the formation of a differentiation zone containing two centrioles and a cytoplasmic protrusion. The centrioles are associated with vestigial striated roots. One of the centrioles develops a free flagellum externally to the cytoplasmic protrusion. After a slight rotation, the free flagellum fuses with the cytoplasmic protrusion. In the final stage of spermiogenesis, a single crested body appears in the anterior part of the differentiating spermatozoon. The anterior extremity of the mature spermatozoon is characterised by an apical cone and a single crested body. The axoneme is of the 9+''1'' trepaxonematan type. A periaxonemal sheath and electron-dense rods are described in some parts of the mature spermatozoon. The nucleus is electron-dense and spirally coiled around the axoneme. The cortical microtubules are spirally arranged at an angle of about 40° to the spermatozoon axis. The present results show that the ultrastructural characters of spermiogenesis and mature spermatozoon of T. rectangula resemble most closely those in taeniids and metadilepidids. The comparison of these results with the only previous spermiological description of a paruterinid species reveals differences relative to the occurrence of filamentous rods of electron-dense material versus intracytoplasmic walls in the mature spermatozoon that may reflect the polyphyletic character of the Paruterinidae.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public