Morpho-functional characteristics of the scolex of Wardium chaunense (Cestoda: Aploparaksidae) penetrated into host intestine.

The scoleces of Wardium chaunense penetrated into the intestinal wall of a snipe (Gallinago gallinago) were examined by light and transmission electron microscopy for the first time. Naturally, the scolex is characterised by a shorter length in comparison with when it is removed from the host. Ultrastructural characteristics of the main parts of the scolex, such as suckers, rostellum and rostellar sac are reported. Partial degradation of the radial muscles of the suckers is clearly recognised; this can be the result of a deep penetration of the scolex into the mucosa and subsequent loss of attachment function by suckers. The muscular walls of the rostellum and rostellar sac have a structure of the same type: an outer longitudinal layer of muscles is separated from the inner circular one with a thin basal matrix, which, also, surrounds each muscular fibre of the circular layer. Circular fibres consist of mutually perpendicular myofibrils, connected with the basal matrix by hemidesmosomes. Microtriches, covering the tegument, vary in shape in different regions of the scolex. They are absent on the apical part of the rostellum, and are slightly curved and can be considered as belonging to the fixative type on the suckers. Special sensory endings with a dense central body and without cilia are situated at the distal cytoplasm of the tegument of the suckers. Two glands, having the same syncytial structure, are disposed inside the rostellum and rostellar sac. Erythroid granules produced by the glands are released during an apocrine process into the host-parasite contact zone. Secretions of the cestode tegument in the form of vesicles and bubbles of granular material were also observed. It is suggested that the scolex attachment method of W. chaunense has the tendency of 'anchoring', which is an irreversible attachment used by some cestode parasites of the snipe.

[Revision of Aploparaksis crassirostris and A. sinensis (Cestoda: Hymenolepididae)]. / Reviziia vidov Aploparaksis crassirostris i A. sinensis (Cestoda: Hymenolepididae).

Based on the examination of specimens of Apoloparaksis crassirostris deposited in the Museum of Zoology in Copenhagen and the Museum of Natural History in Geneva and cestode material from other collections, we have carried out the revision of this species, designated the lectotype and paralectotypes, made its redescriptions, enumerated synonyms, showed the only host of this species in the snipe Gallinago gallinago, and more precisely mapped the distribution range of the parasite. The investigation of the type series of A. sinensis, the parasite of the woodcock Scolopax rusticola, deposited in the Museum of Natural History in Geneva, confirmed the validity of this species, earlier considered as synonym of A. crassirostris. The lectotype and paralectotypes of A. sinensis were designated. Some data on its life cycle have been obtained. It was also found by the experimental invasion that five species of oligochaetes of the family Lumbricidae are intermediate hosts. The metacestodes of this species belongs to the tailed diplocyst modification and posesses a characteristic feature, the bifurcation of tail.

Comparative karyological studies on the species of Eubothrium Nybelin, 1922 (Cestoda: Pseudophyllidea).

Karyotypes of Eubothrium salvelini, E. crassum and Eubothrium sp. were studied using conventional Giemsa staining and comparative karyometric analysis. The karyotypes, reported here for the first time, consist of eight chromosome pairs. The two first pairs of homologues are metacentric and markedly larger than the remaining elements. The obvious similarity in karyotype structure does not exclude the possibility of discriminating E. salvelini and E. crassum using karyotypic characters. The best cytogenetic marker is the last pair of chromosomes, which is acrocentric in the karyotype of E. salvelini and metacentric in that of E. crassum. Karyological observations provide strong evidence for assigning Eubothrium sp. from Clupea harengus membras to E. crassum. Comments are made on the karyotypes of these and related species with respect to their phylogenetic links.

Dichoanotaenia multifilamenta sp. n. (Cestoda: Dilepididae) from the black turnstone, Arenaria melanocephala (Vigors), in Alaska.

Dichoanotaenia multifilamenta sp. n. (Cestoda: Dilepididae) from the Black Turnstone, Arenaria melanocephala (Vigors), in Alaska is described. This cestode is distinguished from other species of the genus Dichoanotaenia López-Neyra 1944 mainly by the structure of the cirrus and of the egg.

[Postembryonic development of cestodes of the genus Aploparaksis Clerc, 1903 (Hymenolepididae) with a diplocyst type of cysticercoid]. / Postémbrional'noe razvitie tsestod roda Aploparaksis Clerc, 1903 (Hymenolepididae) s tsistitserkoidom tipa diplotsisty.

The formation of cysticercoids of the diplocyst type in three species of cestodes of the genus Aploparaksis: A. bulbocirrus Deblock et Rausch, 1968, A. furcigera (Rud., 1819) and A. groenlandica (Krabbe, 1869) at the experimental infection of oligochaetes (Lumbriculus sp.) is described. The development of diplocysts is characterized by two invaginations. The first invagination occurs at an early developmental stage when non-differentiated anterior part of the larval body submerges into the external cyst which is formed by the walls of the primary cavity displaced toward the hind end. The second invagination of the fully formed scolex and neck into the cavity of the internal cyst completes the formation of the diplocysts.

Life-cycle of the cestode Wardium calumnacantha (Schmidt, 1963) comb. n. (Hymenolepididae) from common snipe, Gallinago gallinago (L.).

Post-embryonic development of the cestode Wardium calumnacantha (Schmidt, 1963) comb. n., a parasite of common snipe, was studied by experimental infection of the oligochaetes Neoscolex roseus Morev and Rhyacodrilus coccineus (Vejdovský) carried out in Chukotka. The larvae of W. calumnacantha were ovoid and belonged to the morphological modification of cysticercoid-diplocyst. Two invaginations were observed during the larvogenesis. The first one occurred at the stage of scolexogenesis, when the body of larva was plunged into the external cyst formed by the walls of the primary cavity. Second invagination of the formed scolex and neck into the internal cyst was the final stage of cysticercoid formation.

Aploparaksis borealis sp. n. (Cestoda: Hymenolepididae) from passeriform and charadriiform birds in Chukotka and Alaska.

Aploparaksis borealis sp. n. (Cestoda: Hymenolepididae), from the long-tailed jaeger, Stercorarisu longicaudus Vieillot, on the Seward Peninsula, Alaska, and from the red-throated pipit, Anthus cervinus (Pallas), and the Lapland longspur, Calcarius lapponicus (Linnaeus), in Chukotka, northestern Siberia, is described. This cestode is distinguished by the structure of the cirrus and other morphologic characters from other species of Aploparaksis Clerc 1903 in which there are 10 rostellar hooks and the vitelline gland is aporal to the ovary. A. borealis is the first species of Aploparaksis to be reported from birds representing 2 orders (Passeriformes and Charadriiformes).

A new cestode of charadriiformes-Wardium chaunense sp. n. (Hymenolepididae) from Gallinago gallinago (L.) from Chukotka.

A description and differential diagnosis of Wardium chaunense sp. n. from the common snipe, Gallinago gallinago (L). from Chaun lowland (North-West Chukotka) are presented. This cestode differs from other related species of this genus in the form of rostellar hooks and form and armament of cirrus.

[Life cycles of the Hymenolepis, Aploparaksis birulai Linstow, 1905 and Aploparaksis brachyphallos (Krabbe, 1869)]. / Zhiznennye tsikly Tsestod - Gimenolepidid Aploparaksis birulai Linstow, 1905 i Aploparaksis brachyphallos (Krabbe, 1869)

Larvae of A. birulai from Lumbriculus variegatus and A. brachyphallos from Stylodrilus sp. from the Chauna lowland (Chukotka) are described. The species belonging of the larvae was proved experimentally. It was shown that Cysticercus sp. Hrabe, 1958 is a larvacyst of A. birulai. For larvacysts of A. birulai type the name of "floricerk" was suggested and for those of A. brachyphallos type--the name "tailed diplocyst". It is noted that A. uelcal Spassky et Jurpalova, 1968 is a synonym of A. brachyphallos (Krabbe, 1869) nec A. brachyphallos sensu Davies, 1938.

[Histochemical study of the cysticercoids of cestodes of the genus Aploparaksis Clerc, 1903 (Hymenolepididae)]. / Gistokhimicheskoe izuchenie tsistitserkoidov tsestod roda Aploparaksis Clerc, 1903 (Hymenolepididae)

Hystochemical methods were employed in order to study the distribution of succinic dehydrogenase, glucose-6-phosphate-dehydrogenase, alcaline, acidic phosphatases, lipids, fatty acids, glycogen and neutral. mucopolysaccharides in larvae of three species of cestodes: A. birulai, A. polystictae, A. xemae. A high concentration of succinic dehydrogenase was recorded from the tissue of the tail, scolex and neck. Glycose-6-phosphatdehydrogenase was found in great quantity only in the external parenchyma of the neck of A. polystictae. Here accumulations were observed of lipids which apparently are the products of excretion. The glycogen localization coincides with the distribution of succinis dehydrogenase. The activity of phosphatases is concentration in the structures of the tail and external membranes of cysticercoids, the acidic phosphatase being dominant. It was concluded that aerobic oxidation dominates in larvae and substances are principally transported through the tail area and excretory aperture.

Polymorphism of larvae of the genus Aploparaksis Clerc, 1903 (Hymenolepididae).

The larvae of 12 cestode species of the genus Aploparaksis have been studied. In order to confirm the determination, the definitive hosts, birds, were experimentally infected with 5 species and the intermediate hosts, oligochaetes, with 6 species of cestodes. A great variability was observed in the morphology of tail appendix of cysticercoids belonging to five types of larvae. It is assumed that the polymorphism of larvae of the genus Aploparaksis results from the morphological adaptation to the development under arctic conditions.

[New species of cestodes, Aploparaksis parabirulai sp. n. (Hymenolepididae) from sandpipers in Chukot]. / Novyi vid tsestod--Aploparaksis parabirulai sp. n. (Hymenolepididae) iz kulikov Chukotki

Description and drawings of a new species Aploparaksis parabirulai sp. n. from the intestine of Macrorhamphus griseus, caught in west Chukotka, are given. The main pecularities of the species are such the hooks of the probosis are 0.031--0.034 mm long; cirrus 0.13--0.14 mm long is armed with big triangle spines; vittelaria are situated aporal. Differentiation from related species--A. birulai Linstow, 1905, A. crassipenis Deblock et Rausch, 1968 and A. crassirostris (Krabbe, 1869) is given.