An annotated list and molecular data on larvae of gryporhynchid tapeworms (Cestoda: Cyclophyllidea) from freshwater fishes in Africa

An annotated list of larvae (metacestodes) of gryporhynchid tapeworms (Cestoda: Cyclophyllidea) from freshwater fishes in Africa is provided with numerous new host and geographical records. Newly collected materials from Burundi, Democratic Republic of the Congo, Kenya, Madagascar, Namibia, Senegal, South Africa, Sudan and Zimbabwe practically double the total number of species reported from African fish so far. We confirm the occurrence of 16 species (five unidentified to the species level and most likely representing new taxa) belonging to the genera Amirthalingamia Bray, 1974 (1 species), Cyclustera Fuhrmann, 1901 (2 species), Dendrouterina Fuhrmann, 1912 (1 species), Neogryporhynchus Baer & Bona, 1960 (1 species), Paradilepis Hsü, 1935 (4 species), Parvitaenia Burt, 1940 (5 species), and Valipora Linton, 1927 (2 species). Additionally, metacestodes of four unidentified species of Paradilepis and Parvitaenia are reported from fish for the first time. Rostellar hooks of all species are illustrated and their measurements are provided together with a host-parasite list. The molecular phylogenetic analysis based on partial LSU rDNA sequences offers the first insight into the internal phylogenetic relationships within the family. Together with the morphological observations, the present study provides a taxonomic baseline for future studies on this largely neglected, but widely distributed and relatively frequent, group of parasites of African fishes, including economically important cichlids like tilapias and cyprinids.     

Diversity of Dilepididae (Cestoda: Cyclophyllidea) revealed by cytogenetic analysis

Karyotypes of three dilepidid species: Molluscotaenia crassiscolex, Anomotaenia bacilligera and Dilepis undula, which have not been recorded previously, were studied using conventional Giemsa staining and comparative karyometric analysis. Twelve small biarmed chromosomes were observed in mitotic cells of M. crassiscolex, 16 biarmed chromosomes of gradually decreasing size were found in cells of A. bacilligera, while 18 elements were characteristic for D. undula. These data, together with information available in literature, prove the heterogeneity and possible polyphyletic nature of the family Dilepididae.     

Interrelationships and evolution of the tapeworms (Platyhelminthes: Cestoda)

Interrelationships of the tapeworms (Platyhelminthes: Cestoda) were examined by use of small (SSU) and large (LSU) subunit ribosomal DNA sequences and morphological characters. Fifty new complete SSU sequences were added to 21 sequences previously determined, and 71 new LSU (D1-D3) sequences were determined for the complementary set of taxa representing each of the major lineages of cestodes as currently understood. New sequences were determined for three amphilinidean taxa, but were removed from both alignments due to their excessively high degree of divergence from other cestode sequences. A morphological character matrix coded for supraspecific taxa was constructed by the modification of matrices from recently published studies. Maximum-parsimony (MP) analyses were performed on the LSU, SSU, LSU+SSU, and morphological data partitions, and minimum-evolution (ME) analyses utilizing a general time reversible model of nucleotide substitution including estimates of among-site rate heterogeneity were performed on the molecular data partitions. Resulting topologies were rooted at the node separating the Gyrocotylidea from the Eucestoda. The LSU data were found to be more informative than the SSU data and were more consistent with inferences from morphology, although nodal support was generally weak for most basal nodes. One class of transitions was found to be saturated for comparisons between the most distantly related taxa (gyrocotylideans vs cyclophyllideans and tetrabothriideans). Differences in the topologies resulting from MP and ME analyses were not statistically significant. Nonstrobilate orders formed the basal lineages of trees resulting from analysis of LSU data and morphology. Difossate orders were basal to tetrafossate orders, the latter of which formed a strongly supported clade. A clade including the orders Cyclophyllidea, Nippotaeniidea, and Tetrabothriidea was supported by all data partitions and methods of analysis. Paraphyly of the orders Pseudophyllidea, Tetraphyllidea, and Trypanorhyncha was consistent among the molecular data partitions. Inferences are made regarding a monozoic (nonsegmented) origin of the Eucestoda as represented by the Caryophyllidea and for the evolution of the strobilate and acetabulate/tetrafossate conditions having evolved in a stepwise pattern.     

On a life cycle of Unciunia raymondi (Cestoda: Cyclophyllidea: Dilepididae)

Cysticercoids of the cestode Unciunia raymondi Gigon et Beuret, 1991 (Cyclophyllidea: Dilepididae), a parasites of palaearctic thrushes (Turdus), taken from spontaneously infected Geotrupes and black wireworm Cylindrojulus in the North-eastern Altai, is described. An identity of cysticercoids of U. raymondi and Ditestolepis diaphana sensu Kisilewska, 1960 has been stated. During the development within the fibrillate membrane, the metacestode of U. raymondi separates the cercomer from the cyst anlage in the late scolexogenesis. There is no the primary lacuna in the lamellated cercomer without any musculature. Its primarily smooth surface gradually becomes sulcate and plicate. In the result of some segments break-up, the cercomer lamella comes to be perforated with its margins deeply jagged. Metacestode of U. raymondi metacestode is compared with cryptocercus of Dilepididae, which also develops within the fibrillate membrane. Based on peculiarities of the morphogenesis of cercomer, the cysticercoid U. raymondi is assigned to a new morpho-ecological type, the placocercus.     

Checklist of tapeworms (Platyhelminthes,Cestoda) of vertebrates in Finland

A checklist of tapeworms (Cestoda) of vertebrates (fishes, birds and mammals) in Finland is presented, based on published observations, specimens deposited in the collections of the Finnish Museum of Natural History (Helsinki) and the Zoological Museum of the University of Turku, and additional specimens identified by the present author. The checklist includes 170 tapeworm species from 151 host species, comprising 447 parasite species/host species combinations. Thirty of the tapeworm species and 96 of the parasite/host species combinations have not been previously reported from Finland. The total number of tapeworm species in Finland (170 spp.) is significantly lower than the corresponding figure for the Iberian Peninsula (257 spp.), Slovakia (225 spp.) and Poland (279 spp.). The difference between Finland and the other three regions is particularly pronounced for anseriform, podicipediform, charadriiform and passeriform birds, reflecting inadequate and/or biased sampling of these birds in Finland. It is predicted that there are actually ca. 270 species of tapeworms in Finland, assuming that true number of bird tapeworms in Finland corresponds to that in other European countries with more comprehensive knowledge of the local tapeworm fauna. The other main pattern emerging from the present data is the seemingly unexplained absence in (northern) Fennoscandia of several mammalian tapeworms that otherwise have extensive distributions in the Holarctic region or in Eurasia, including the northern regions. Previously unknown type specimens, that is, the holotype of Bothrimonus nylandicus Schneider, 1902 (a junior synonym of Diplocotyle olrikii Krabbe, 1874) (MZH 127096) and the syntypes of Caryophyllaeides fennica (Schneider, 1902) (MZH 127097) were located in the collections of the Finnish Museum of Natural History.     

Structure of the copulative apparatus of Sobolevicanthus gracilis (Cestoda: Cyclophyllidea)

Fine structure of genital atrium, Furman body, distal region of vagina and sac cirrus were investigated. The broad polymorphism of surface microstructures (microtriches) in various parts of copulative apparatus has been revealed. The constitution of prostate glands, being the modified cytons of syncitial epithelium of the intrabursal section of spermaduct wall, is described. Based on obtained and reference data, a comparative morphological analysis of copulative apparatus organization in lowest and highest cestodes was carried out. The hypothesis suggests that evolution of its organization was connected with the reduction of the muscular elements and simultaneous improvement of their managing, their isolation from surrounding parenchyma and development of supporting connective tissue elements. It is shown, that Fuhrmann's body has its own developed muscular system armed with power microtriches and being capable to evaginate into the distal region of vagina. It is supposed that S. gracilis obtains of two different ways of copulation in: by means of cirrus that executes the cross fertilization; and by means of the additional copulative formation--Furman body, which guarantees the self fertilization of worms.     

Development of the Embryonic Envelopes of Mesocestoides lineatus (Cestoda: Cyclophyllidea)

Summary

Transmission electron microscopy revealed that the eggs of Mesocestoides lineatus consisted of an oncosphere larva surrounded by various coverings. The outermost of these was the embryonic capsule, which appeared as a thin electron-dense membranous sac. The capsule enclosed inner and outer embryonic envelopes, each of which was syncytial and apparently formed from embryonic blastomeres. The envelopes became increasingly vesiculated during embryogenesis, and were attached to each other by desmosomes by the time the larva was fully formed. An electron-dense intracellular embryophore was produced by the inner envelope; it first appeared under the distal plasma membrane as a series of blocks, which grew and fused to form a thick unbroken layer. Early in development, the proximal plasma membrane of the inner envelope was connected to the larval epithelium by a multilaminate membrane complex that was ultrastructurally similar to a continuous junction. At the end of embryogenesis, this appeared to detach from its formative cells on both sides to form the distinctive oncospheral membrane. Several eggs were bound together in clusters by a cluster capsule that was ultrastructurally identical to the individual embryonic capsules. This type of egg packaging has not been described previously for any cestode. Both the cluster and individual capsules broke down by the end of embryogenesis.     

扩张莫尼茨绦虫(绦虫纲:圆叶目)卵黄细胞发育的超微结构

用透射电镜观察了扩张莫尼茨绦虫(Moniezia expansa)卵黄细胞发育的全过程。扩张莫尼茨绦虫卵黄细胞发育的规律为：(1)细胞体积不断增大;(2)质、核比不断增加而核体积几乎不发生改变,核表面从规则变为不规则,再由不规则变为规则,核内出现染色质浓缩成小块再分散的发育变化过程;(3)线粒体逐渐增多,发育不断完善;(4)粗面内质网及高尔基复合体出现由少到多,发育不断完善,再由多到少不断退化的变化;(5)由高尔基复合体组装的电子致密的小卵黄囊不断融合,至卵黄细胞成熟时仅有一卵黄囊,占据细胞大部分体积[动物学报49(2)：256—261,2003]。     

A taxonomic revision of the Nematotaeniidae Lühe, 1910 (Cestoda: Cyclophyllidea)

A taxonomic revision of the Nematotaeniidae, involving the examination of over 400 specimens, was undertaken. Some new taxonomic characters have been introduced to allow distinction of the various species. The family contains 18 recognized species in four genera. The genusNematotaenia Lühe, 1910 contains four species, namelyN. chantalae Dollfus, 1957,N. dispar (Goeze, 1782) Lühe, 1910,N. hylae Hickman, 1960, andN. tarentolae Lopez-Neyra, 1944.N. kashmirensis Fotedar, 1966,N. dollfusi, Yuen & Fernando, 1974 andN. viride Mokhtar-Maamouri & Chakroun, 1984 are considered junior synonyms ofN. dispar. N. aurangabadensis Chincholikar & Shinde, 1975,N. lopezneyrai Soler, 1945 andN. mabuiae Shinde, 1968 are consideredspecies inquirendae: the latter species probably belongs in the genusOochoristica Lühe, 1898 (Anoplocephalidae: Linstowiinae). The genusCylindrotaenia Jewell, 1916 is shown to possess two testes per segment and not one as originally proposed:Baerietta Hsü, 1935 is consequently synonymized withCylindrotaenia. Cylindrotaenia is divided into five species-groups on the basis of adult morphology. The first group contains two American species, namelyC. americana Jewell, 1916 andC. idahoensis (Waitz & Mehra, 1961) n. comb. The second group contains species from Australia and New Zealand, namelyC. allisonae (Schmidt, 1980), n. comb.,C. criniae (Hickman, 1960) n. comb.,C. decidua (Ainsworth, 1985) n. comb.,C. hickmani (Jones, 1985) n. comb. andC. minor (Hickman, 1960) n. comb. A third species group consists ofC. jaegerskioeldi (Janicki, 1926) n. comb.,C. magna n. sp. andC. philauti Crusz & Sanmugasunderam, 1971 and occurs in Africa, Sri Lanka and Japan. The fourth group, apparently restricted to Japan, contains a single species,C. japonica (Yamaguti, 1938) n. comb. The fifth group containsC. montana (Yamaguti, 1954) n. comb. and occurs in Japan and Tibet.C. quadrijugosa Lawler, 1939 is synonymized withC. americana, andBaerietta claviformis Yamaguti, 1954 is synonymized withC. japonica. C. baeri (Hsü, 1935) n. comb.,C. chilensis (Puga & Franjola, 1983) n. comb.,C. diana (Helfer, 1948) Lehmann, 1960,C. malayi (Yuen & Fernando, 1974) n. comb. andC. roonwali Nama, 1972 arespecies inquirendae. The genusDistoichometra, Dickey 1921 contains a single species, namelyD. bufonis Dickey, 1921.D. kozloffi Douglas, 1958 andBaerietta enteraneides (Helfer, 1948) Yamaguti, 1959 are reduced to synonymy withD. bufonis. Bitegmen n. g. is proposed to accomodate a single species,B. gerrhonoti (Telford, 1965) n. comb., which was previously included in the genusBaerietta. The present distribution of the Nematotaeniidae is largely related to that of their anuran hosts. Nematotaeniids probably arose in Gondwanaland.     

Matabelea fuhrmanni (Cestoda, Cyclophyllidea, Paruterinidae): redescription, synonymy and systematic position

Matabelea fuhrmanni (Southwell. 1925) comb. n. [syns Lateriporus fuhrmanni Southwell. 1925: Culcitella fuhrmanni (Southwell) Baer in Fuhrmann, 1932; Matabelea aetodex Mettrick. 1963. new synonym] is redescribed on the basis of the type-specimens of L. fuhrmanni and M. aetodex plus additional specimens from African birds of prey. Matabelea Mettrick. 1963 is regarded as a monotypic genus of the family Paruterinidac and not of the family Dilepididae. where it was originally placed. The host range of M. fuhrmanni includes the African falconiform birds Cireaetus cinereus. Melierus metabates and Aquila rapax (Accipitridac) plus Falco biarmicus (Falconidae).