New species of Cinclotaenia macy, 1973 (Cyclophyllidea: Dilepididae) from Cinclus leucocephalus tschudi (Passeriformes: Cinclidae) in Bolivia

Two new species of Cinclotaenia (Cyclophyllidea: Dilepididae) are described from the small intestine of Cinclus leucocephalus (Aves: Passeriformes: Cinclidae) collected in the Yungas region of Bolivia. Cinclotaenia minuta n. sp. is characterized by possessing a minute strobila with a maximum body length of 1.58 mm, consisting of 5-10 proglottids, 19-22 rostellar hooks with lengths from 16 to 17 microm, 12-17 testes per proglottid, and eggs forming packets without filaments. Cinclotaenia boliviensis n. sp. has bandlike strobila with a length up to 26 mm with 67-74 proglittids, 22 rostellar hooks with length 39-42 microm, 43-68 testes, and eggs forming packets possessing long filaments. The systematic position in Cinclotaenia of cestodes lacking filaments on the egg packets is confirmed. This is the first record of species of Cinclotaenia in dippers from Bolivia and also the first report of cestodes from Cinclus sp. in the Neotropical Region.     

Activity of digestive enzymes of thick-billed murre (Uria lomvia) and common murre (U. aalga) invaded by cestodes

Activities of digestive enzymes (proteases, carbohydrases, acid and alkaline phosphatases) are determined in intestinal mucosa of the thick-billed and common murres Comparative analysis of the obtained results is performed for non-infected and for birds infested by cestodes. It has been established that at invasion by cestode Alcataenia armillaris (Cestoda: Tetrabothriidae), activities of carbohydrase and alkaline phosphatase in intestinal mucosa of the thick-billed murre decreases. Parasitizing of cestodes Tetrabothrius jaegerskieldi (Cestoda: Tetrabothriidae) in intestine of the common murre induces a decrease of saccharase activity. There is studied kinetics of desorption of enzymes from digestive-transport surfaces of the bird intestine. Peculiarities of firmness of enzyme fixation are established on the surface of intestinal mucosa of invaded murres. According to the obtained data, a decrease of the carbohydrase activities in intestine of infested murres is likely to be due to absorption of a part of enzymes hydrolyzing carbohydrates on the surface of cestodes.     

Comparative cytogenetics of Diphyllobothrium ditremum (Creplin, 1925) and Ligula intestinalis (Linnaeus, 1758) (Cestoda: Pseudophyllidea)

An investigation carried out on two species of pseudophyllidean cestodes belonging to different families showed very close karyological affinity between them. The karyotypes of Diphyllobothrium ditremum and Ligula intestinalis both consist of 18 bi-armed chromosomes and are almost identical with respect to the relative length and the centromeric indices of corresponding chromosomes. Statistically significant differences exist in the morphology of chromosomes 2 and 4, but they are not striking and may be due in part to errors of measurement. Differences in the absolute length of the chromosomes were noted: the chromosomes of D. ditremum are somewhat larger (from 2.7 to 8.5 μm) than those of L. intestinalis (from 1.9 to 5.4 μm). The results obtained were compared with data existing for other pseudophyllidean cestodes and preliminary conclusions on the karyotypic evolution in that group of helminths were made.     

Fine structure of the female reproductive system in Sobolevicanthus gracilis and Cloacotaenia megalops (Cestoda: Cyclophyllidea)

The fine structure of the female reproductive organs and ducts in two cyclophyllidean cestodes was studied by transmission electron microscopy. All the studied ducts (vitelline, fertilization and vaginal ducts, and oviducts) as well as the uterine and ootype walls have the luminal surface elevated to form apical cytoplasmic lamellae and are surrounded by bands of circular muscules, which are attached to the basement layer. The structure of the studied ducts epithelium corresponds to the pattern described in other ducts of the cestode genital system, namely a nucleate syncytial layer. An exception is the vagina Sobolevicanthus gracilis, in which the surface is lined with not numerous atypical microtriches. The comparison of our results and the data reported for other species is given. It is found out that in different species of cestodes forming oligolecital eggs, there are observed various uterine structures and diverse contacts between the eggs capsules and the uterine epithelium. The formation of special structures and contacts is the evolutionary way from the extrauterine type to more progressive intrauterine type of embryo development in cestodes.     

Spermiogenesis and sperm ultrastructure of Cyathocephalus truncatus (Pallas, 1781) Kessler, 1868 (Cestoda: Spathebothriidea)

Spermiogenesis and sperm ultrastructure of adult Cyathocephalus truncatus, a member of presumably basal group of "true" cestodes (Eucestoda), have been examined for the first time by using transmission electron microscopy. The process of sperm formation corresponds in basic pattern to that of the Pseudophyllidea. In addition, the 2 pairs of electron-dense attachment zones are present in median cytoplasmic process of C. truncatus. However, mature spermatozoa of C. truncatus differ significantly from those of the pseudophyllideans, especially in the morphology of the proximal and distal spermatozoon extremities. The proximal extremity of the mature spermatozoon lacks a crested body, which is present in more derived cestodes and some pseudophyllideans. The distal end of the mature spermatozoa exhibits different morphology in the gametes from testes and those from receptaculum seminis. New for the Eucestoda is a finding that a lateral cytoplasmic extension creates the distal end of the spermatozoa from testes, resembling sperm of some Monogenea and Digenea. In contrast, the distal extremity of the spermatozoa from receptaculum seminis contains only a nucleus. Despite the above-mentioned peculiarities, the ultrastructural data on sperm/spermiogenesis suggest close relationships of the Spathebothriidea and Pseudophyllidea.     

ASEXUAL REPRODUCTION IN CESTODES (CYCLOPHYLLIDEA: TAENIIDAE): ECOLOGICAL AND PHYLOGENETIC INFLUENCES

Asexual reproduction, a rare trait among cestodes in general, occurs in the “larval” (metacestode) stage of species of the family Taeniidae. The distribution of this trait among taeniid species is not consistent with an ecological hypothesis of current environmental predictability. We therefore chose a subset of the family and studied their phylogenetic relationships by Wagner parsimony analysis as a test of historical influences on asexual reproduction. We produced a consensus tree based on four 50-step trees with consistency indices of 0.38. Given these hypothetical relationships, we found that asexual reproduction either arose or was lost multiple times. Moreover, this consensus tree is incongruent with both definitive and intermediate host phylogenies, and asexual reproduction does not correlate with host transfers inferred from these phylogenies. Developmental and phylogenetic constraints on asexual reproduction therefore appear to have been minimal. Given current information, neither historical constraint nor explanations invoking adaptation based on environmental predictability can account for life-history variation in these cestodes.     

Carbohydrate metabolism of Bothriocephalus scorpii (Cestoda: Bothriocephalidae)

The cestodes Bothriocephalus scorpii during the incubation in vitro assimilated glucose from the incubation medium and synthesized of glycogen. End products of carbohydrate metabolism in B. scorpii were lactic, succinic and volatile fatty acids. Mitochondria isolated from B. scorpii intensively oxidized succinate, alpha-ketoglutarate, isocitrate and less intensevely oxidized citrate, oxalacetate, pyruvate, cis-aconitate and malate.     

The occurrence of Eubothrium fragile (Cestoda: Pseudophyllidae) in twaite shad, Alosa fallax (Lacépède) in the River Severn

The occurrence, size and maturity changes of Eubothrium fragile have been studied in postlarvae, juveniles and adult twaìte shad, Alosa fallax , from several locations in the River Severn. Parasites were only found in adult shad and not in post-larvae or juveniles. No juvenile or recently acquired cestodes were identified as such, but adults were present in shad throughout the whole period of their spawning migration. A large proportion of the parasites were gravid upon arrival in the river and, although eggs were subsequently released into fresh water, there was no loss of cestodes from the fish. It was concluded that E. fragile is a marine species, that the parasites found in adult shad in fresh water were the residue of a marine life cycle and that the eggs released in fresh water were part of the parasite's natural reproductive wastage. The distribution and biology of E. fragile were discussed and it is considered that it is typical of the marine species of the genus.     

Ultrastructure of nephridial systems in cyclophyllidean cestoda: Catenotaenia pusilla (Goeze, 1782), Hymenolepis diminuta (Rudolphi, 1819) and Inermicapsifer madagascariensis (Davaine, 1870) Baer, 1956]

Electron microscopic study of nephridial systems in three cyclophyllidean cestodes indicates a resemblance in their ultrastructure. The walls of longitudinal, transverse and collecting ducts show a very similar pattern of organization. The surface of the anucleate epithelium lining the ducts is developed into microvilli. A relatively thick layer of fibrillar tissue underlies the basal membrane of the microvillar epithelium. The nucleated portions or "pericaryons", situated between the parenchymal cells, are directly connected with epithelium by cytoplasmic prolongations. The canalicular lumen extends through a single series of cells curved into a ring. The epithelial surface of the canalicular wall is developed into short, densly staining microvilli and the immediately underlying fibrillar tissue appears very compact. The cilia were never observed in any of the above ducts. The ultrastructure of protonephridia proper is comparable with those already described in other cestodes. There is a close association between the flame-cell and the cancalicular ending, enlarged into a nephridial funnel. A single row of nephridial rods of the flame-cell is surrounded by a row of digitiform prolongations of the nephridial funnel border. The prolongations alternate with the rods and their interlocking pattern appears clearly in cross-sections. A series of minute pores or "nephrostomes" providing a direct contact between the nephridial chamber and intercellular space of the paranchyma was shown. The problem of classification and definition between the "closed" protonephridia and open metanephridia is discussed. The structural unity of protonephridia in different groupes of Platyhelminthes is reviewed. The different number of flagella within the "flames" of different cestodes is compared and analyzed. The ultrastructural characteristics of duct-wall epithelium provides some confirmation of its high metabolic activity.     

Proteinase Activity in the Intestine of Ruff <Emphasis Type="Italic">Gymnocephalus cernuus</Emphasis> (L.) (Pisces) Depending on the Sum Length of Cestodes <Emphasis Type="Italic">Proteocephalus cernuae</Emphasis> (Gmelin) Parasitizing the Gut

It is revealed that the infection of ruff with cestodes Proteocephalus cernuae affects the activity of its intestinal proteolytic enzymes. The influence of cestodes on the activity of intestinal proteinases depends on the sum length of the worms occupying the gut. Proteinase activity decreases at a smaller total length of the worms and increases at larger total length, with serine proteinases being mostly involved. The essential share of activity is presented with metalloproteinases, which can indirectly evidence the important role of microbiota in the digestion of ruff. The small share of cysteine proteinases in both uninfected and infected fish may indicate minor intestinal damages caused by the attachment structures of cestodes.     

Revision of the Progamotaenia zschokkei (Janicki, 1905) complex (Cestoda: Anoplocephalidae), with the description of six new species

A review of cestodes currently attributed to Progamotaenia zschokkei (Janicki, 1905) (Cestoda: Anoplocephalidae) suggests that six additional species are present: Pr. tenuis n. sp. found in Thylogale stigmatica (Gould) and T. thetis (Lesson), Pr. lomatosoma n. sp.from Macropus agilis (Gould), Pr. petrogale n. sp. from Petrogale spp. and Macropus dorsalis(Grey), Pr. fimbriata n.s p. from Lagorchestes conspicillatus Gould and L. hirsutus Gould, Pr. obesa n. sp. from Onychogalea fraenata (Gould) and O. unguifera (Gould) in north-eastern Australia and Pr. kellerae n. sp. from O. unguifera in north-western Australia. The new species are differentiated by a combination of characters: prominence of scolex lobes, number of lobes in the fimbriated velum, testis number and distribution, size of the cirrus-sac, morphology of the uterus and presence or absence of a pyriform apparatus in eggs from terminal segments. The morphological differences found support earlier molecular studies, in that cestodes within each host genus are distinct, with the exception that considerable morphological variation exists within Pr. petrogale. Principal components analysis suggested that most of the cestodes from Petrogale spp. belonged to Pr. petrogale. The status of specimens from Pe. lateralis is unclear. More detailed molecular studies are required to determine the significance of the morphological variation within this taxon. A key is provided to species within the complex and the related species Pr. villosa (Lewis, 1914).     

Helminth associations in white-toothed shrews Crocidura russula (Insectivora: Soricidae) from the Albufera Natural Park, Spain

The helminths of 218 white-toothed shrews from 29 sites in 2 biotopes in the Albufera Natural Park (Valencia, Spain) were examined from July 1990 to August 1991. An association analysis of helminths occurring at a prevalence of more than 4% was carried out for 4 species of cestodes located in the intestine (Hymenolepis pistillum, H. scalaris, H. tiara, and Pseudhymenolepis redonica) and 3 species of nematodes (Pseudophysaloptera sp. located in the stomach, Stammerinema rhopocephala larvae in the intestine and abdominal cavity, and Porrocaecum sp. in the thoracic and abdominal cavities). Bivariate (species pairs) versus multivariate analyses (associations within the entire set of species) were performed of presence-absence and of quantitative records (influence of intensity on associations). The associations were evaluated with respect to the sex and age of the host and to the sampling date and sites. The host and environment played a limited role, and the major determinant of species assemblage was phylogenetic. Positive associations were found among both the cestodes and the nematodes, whereas negative associations were found between cestodes and nematodes. The type of life cycle was probably the second greatest determinant of species associations. Nematodes using shrews as a paratenic host or as their definitive host were both positively associated.     

Morphology and ultrastructure of reproductive organs of <Emphasis Type="Italic">Monocercus arionis</Emphasis> (Sibold, 1850) Villot, 1982 (Cestoda: Cyclophyllidea)

The morphology of the reproductive system at different stages of ontogenesis and ultrastructural peculiarities of the copulatory organs and uterine in Monocercus arionis (Sibold, 1850) Villot, 1982 (Cyclophyllidea) have been studied. The muscle of the outer wall of the cirrus bag has a higher organizational level than typical smooth-muscle cells in cestodes. The cirrus is armed with typical filamentous and bladelike microtriches. The uterine epithelium contacts the thin capsule of the developing embryos located closely to the uterus wall, and the embryos contact each other in the uterine cavity in what can be interpreted as placental interactions. The specificity of the structure and arming of the copulatory apparatus has been considered, and the ultrastructural peculiarities of the uterus in the members of different orders of cestodes have been compared and analyzed.     

Occurrence of Proteocephalus tetrastomus (Rudolphi, 1810) (Cestoda: Proteocephalidea) in larval rainbow smelt (Osmerus mordax) in North America: identification of a potential pathogen confirmed

A morphological evaluation and genetic analysis (sequencing of ITS2 region of rDNA) of proteocephalidean cestodes from rainbow smelt (Osmerus mordax) in the Saint Lawrence Estuary, Canada, has shown their conspecificity with Proteocephalus tetrastomus, a specific parasite of smelt (Osmeridae), previously known only from northern Europe, Russia, and Japan. The parasite occurs only in larval, but not adult, smelt in the Saint Lawrence Estuary. Prevalence of larval smelt infection was 42% (n = 50), mean intensity 2.1 +/- 2.4 and mean abundance 1.1 +/- 1.0.     

Specific features of the numbers and structure of the population of Proteocephalus longicollis (Zeder 1800) (Cestoda: Proteocephalidea)—A mass parasite of whitefish Coregonus lavaretus L. under conditions of technogenic pollution of the water body

The numbers, age structure, and morphological variation of the cestode Proteocephalus longicollis from whitefish of a natural water body (Kamennoe Lake) and those of Kostomuksha Lake polluted with wastes of the mining industry (northern Karelia) have been studied. In the polluted water body, a high infestation of whitefish and domination of larval stages in the structure of the parasite population have been established. It is shown that under conditions of pollution, only one of the variations of scolex signs dominates in the structure of phenotypic diversity. The size indices of cestodes are reliably smaller as compared with cestodes from the natural water body. The data obtained indicate that technogenic pollution determines a decrease in the intrapopulation diversity of P. longiocollis, and a decrease in the values of morphometric characters indicates inhibition of the morphophysiological state of individuals.     

Lanfrediella amphicirrus gen. nov. sp. nov. Nematotaeniidae (Cestoda: Cyclophyllidea), a tapeworm parasite of Rhinella marina (Linnaeus, 1758) (Amphibia: Bufonidae)

The family Nematotaeniidae, tapeworms commonly found in the small intestines of amphibians and reptiles, includes 27 recognised species distributed among four genera: Bitegmen Jones, Cylindrotaenia Jewell, Distoichometra Dickey and Nematotaenia Lühe. The taxonomy of these cestodes is poorly defined, due in part to the difficulties of observing many anatomical traits. This study presents and describes a new genus and species of nematotaeniid parasite found in cane toads (Rhinella marina) from eastern Brazilian Amazonia. The cestodes were collected during the necropsy of 20 hosts captured in the urban area of Belém, Pará. The specimens were fixed and processed for light microscopy, scanning electron microscopy (SEM) and three-dimensional (3D) reconstruction. Samples were also collected for molecular analyses. The specimens presented a cylindrical body, two testes and paruterine organs. However, they could not be allocated to any of the four existing nematotaeniid genera due to the presence of two each of dorsal compact medullary testes, cirri, cirrus pouches, genital pores, ovaries and vitelline glands per mature segment. Lanfrediella amphicirrus gen. nov. sp. nov. is the first nematotaeniid studied using Historesin analysis, SEM and 3D reconstruction, and it is the second taxon for which molecular data have been deposited in GenBank.     

Populations of Bothriocephalus claviceps (Goeze) (Cestoda) in the European eel, Anguilla anguilla (L.), in three localities in southwest England

The population biology of Bothriocephalus claviceps (Goeze) has been investigated in the European eel, Anguilla anguilla (L.), in three localities in southwest England. Monthly changes in prevalence and abundance show no statistically significant seasonality, in contrast to growth and reproduction of the cestode. The cestode reaches maximum size and becomes gravid mainly in summer. Gravid cestodes die and are lost soon after reproduction. This overlaps with recruitment of the new generation into eels, and may result in a rapid increase in infection levels and in a more over-dispersed distribution of the parasite in some localities, or in a more gradual change in infection levels and over-dispersion in others. Development and growth of the new generation may cease until the following spring, or continue at a slow rate over winter. Parasite numbers in each host decrease well before they actually reach maturity, since the majority of gravid individuals are present in those eels which harbour only one parasite. This suggests that few cestodes develop to maturity and most are lost from hosts as development proceeds.     

Parasites present in foxes (Vulpes vulpes) of the province of Forli

In the period March 1983 - March 1984 a parasitological survey was carried out on 103 foxes killed in the Forli province (Italy). The parasites identified were: Toxocara canis (45.6%); Uncinaria stenocephala (14.6%); Mesocestoides lineatus (9.7%); Dipylidium caninum (2.9%); Taenia crassiceps (2.9%); Trichuris vulpis (2.9%). Out of all the cestodes found in 7 animals the authors identified only genus Taenia since their preservation conditions were not optimal. Other 13 subjects contained many cestodes similar to T. hydatigena, but considerably shorter in the mean length (20 cm vs 200). In a fecal sample the authors found a species of coccidium whose features do not correspond to any of those described in foxes, therefore it was called Eimeria sp. Finally, the autopsies' results were compared with coprological ones in order to asses their reliability.