bluuebunny/crossref_metadata_2025 huggingface dataset:
The activity periods and life-cycle of the tick Ixodes uriae (Acari: Ixodidae) in relation to host breeding strategies
Authors: Barton T. R. , Harris M. P. , Wanless S. , Elston D. A.
Published: June 2009

We investigated the timing of seasonal activity of the seabird tick Ixodes uriae by examining engorgement rates of off-host ticks and the prevalence of infested common guillemots (Uria aalge) and kittiwakes (Rissa tridactyla) on the Isle of May, Scotland. More than 99% of I. uriae fed during the period late April to early August which coincided with the seabird breeding season. No ticks fed in the autumn and winter, and none over-wintered in the engorged state. Peak tick feeding activity was during the hosts' incubation period in May and early June, when over 70% of birds were parasitized. Few ticks were active when guillemot chicks were being brooded, or during the early part of kittiwake chick-rearing. Adult female tick feeding peaked in the first week of June, while nymphal and larval activity peaked in the third week of May. Adult female ticks fed later than nymphs on guillemots and larvae on both guillemots and kittiwakes; however, there was considerable temporal overlap in the feeding periods of the 3 stages on both hosts. All larvae and nymphs fed in May and early June, but up to 18% of adult females remained unengorged at this time, and probably deferred feeding by 1 year. A small proportion of individuals which fed as larvae in May appeared to feed again as nymphs in July of the same season, thereby shortening their life-cycle by 1 year. The duration of the life-cycle of I. uriae on the Isle of May is typically 3 years but varies from 2 to 4 years. Ticks feeding on guillemots did so significantly earlier than those feeding on kittiwakes, possibly because guillemots start breeding earlier in the year. Breeding of both guillemots and kittiwakes was later in 1994 than in 1993. This delayed the activity of all tick stages on kittiwakes and adult female ticks on guillemots, but did not affect the timing of activity of nymphs or larvae feeding on guillemots.
Targeted anthelminthic treatment of school children: effect of frequency of application on the intensity of Ascaris lumbricoides infection in children from rural Nigerian villages
Authors: Holland C. V. , Asaolu S. O. , Crompton D. W. T. , Whitehead R. R. , Coombs I.
Published: June 2009

A study to compare the effects of different frequencies of targeted chemotherapy with levamisole (Ketrax: JAGAL Pharma, Lagos, Zeneca Pharmaceuticals UK) as an action for the control of Ascaris lumbricoides was carried out in 3 communities in rural Oyo State, Nigeria. The targeted group comprised children, aged 5 to 15 years, attending primary school within their village. Treatment was provided within the school with the assistance of the school teachers. Three frequencies of targeted treatment were offered. In one village targeted treatment was provided on 1 occasion in 1 year, in another village at two 6-monthly intervals and in the third village every 4 months. Prevalence and intensity (e.p.g.) of A. lumbricoides infection were determined immediately before and after the period of intervention using a modified Kato–Katz technique. In the villages which received treatment once and at 6-monthly intervals, a reduction in post-treatment intensity of A. lumbricoides was observed in the total population but this failed to attain statistical significance. In contrast, within the village which received 4-monthly targeted chemotherapy, a significant reduction in post-treatment intensity of A. lumbricoides was observed in the total population and in the targeted children. In general, reductions in the intensity of A. lumbricoides after intervention were not particularly pronounced in untreated children (aged 0–4 years) even in the 4-monthly targeted village, whereas in untreated adults, reductions approached statistical significance in villages which received targeted treatment once and at 4-monthly intervals.
Identification and sequence comparison of a cuticular collagen ofBrugia pahangi
Authors: Bisoffi M. , Betschart B.
Published: June 2009

The cuticle of filarial nematodes is a specialized extracellular matrix that covers the parasite and protects it from adverse conditions of the environment. As a surface structure it is in direct contact with the host defence mechanisms and therefore plays an important role in the molecular host-parasite relationship. Using polyclonal antisera raised against the insoluble components of the cuticle of the adult filarial parasiteBrugia pahangi, we have isolated cDNA clones encoding collagen molecules of the cuticle. The protein domain structure of cDNA clone Bpcol-1 was compared with the known structures of cuticular collagens of the nematodesBrugia malayi, Caenorhabditis elegans, Ascaris suumandHaemonchus contortus, confirming interspecies similarities. Using affinity-purified anti-Bpcol-1 antibodies we identified Bpcol-1 antigenic determinants in different nematode extracts, and determined the localization of such epitopes within the cuticle ofB. pahangi.
Effects of pH on a high conductance Ca-dependent chloride channel: a patch-clamp study inAscaris suum
Authors: Robertson A. P. , Martin R. J.
Published: June 2009

Plasma membrane vesicles prepared from the bag region of the somatic muscle cells of the parasitic nematodeAscaris suumcontain high conductance, voltage sensitive, Ca-dependent chloride channels, suggested to be involved in the excretion of carboxylic acids produced by the anaerobic respiration of glucose (Valkanov, Martin & Dixon, 1994). The effect of altered pH on this channel was investigated using the patch-clamp technique and isolated inside-out membrane patches. Changes in pH had little effect on channel conductances and only a small effect on reversal potentials. Under control conditions (symmetrical pH 7·2) the channel had the highest probability of opening at ∼ — 35 mV (the resting membrane potential of the cell). At positive membrane potentials the probability of opening decreased. The Boltzmann equation was used to describe the relationship between membrane potential and probability of channel opening, and to calculate the effective gating charge. Reduction of external pH produced an increase in the probability of channel opening at hyper-polarized membrane potentials. An increase in internal pH caused a voltage-independent increase in the probability of channel opening and made the effective gating charge less negative. The effect of reducing internal pH was marked: the channel then opened most frequently at positive membrane potentials and the probability of opening at —35 mV was greatly reduced. The decrease in internal pH changed the polarity of the effective gating charge. A simple model was constructed to describe the effects of pH on channel gating.
Density-dependent processes in the transmission of human onchocerciasis: relationship between microfilarial intake and mortality of the simuliid vector
Authors: Basáñez M. G. , Townson H. , Williams J. R. , Frontado H. , Villamizar N. J. , Anderson R. M.
Published: June 2009

In order to construct an analytical model of onchocerciasis transmission, it is necessary to elucidate the functional relationships of the various population rate processes taking place within the human and vector hosts. Two previous papers have explored the evidence for density-dependent regulation in relation to microfilarial intake by, and larval development within, theSimulium host. This paper investigates the survivorship of wild-caught blackfly samples fed on subjects with different intensities ofOnchocerca volvulusmicrofilarial infection. Analyses were based on data for GuatemalanS. ochraceum s.l.(possessing a well-developed cibarial armature), West AfricanS. damnosum s.l.(forest species), and South VenezuelanS. guianense(the latter two lacking a toothed cibarium). The mean survival times of samples of the 3 species, kept under laboratory conditions, decreased as parasite intake increased, the rate of mortality being dependent on the fly’s age (measured as time post-feeding) and on the worm load acquired. An empirical, timedependent hazard function was fitted to observed death rates/fly/day which rose very shortly after engorgement, declined subsequently, and rose again throughout the extrinsic incubation period of the parasite. The parameters of this hazard model were all positively correlated with the density of microfilariae in the bloodmeal. Expressions of survivorship and life-expectancy as explicit functions of time post-feeding and mean parasite intake were derived. The average expectation of life at engorgement for uninfected flies in the laboratory was estimated to be around 1 week for both, armed and unarmed blackflies. Residual life-expectancy decreased with time post-feeding and microfilarial load in both categories of vectors. This decline (resulting from age- and parasite-dependent mortality rates) was much more pronounced in those species lacking a toothed fore-gut. Whilst a fraction of heavily infectedS. ochraceumwas able to survive the latent period of the parasite, being therefore potentially capable of transmitting the infection, equivalent worm loads inS. guianenseresulted in a drastic reduction of the expectation of infective life. These results provide additional evidence to support the hypothesis that, in the case of intrinsically susceptible vectors, unarmed simuliids are more efficient at low microfilarial loads, when the transmission rate from human to vector host is higher, and parasite-induced fly mortality is negligible. The opposite takes place in armed flies, which perform poorly at low parasite burdens and better at heavier loads, with little parasite-induced vector death.
Physiological effects of platyhelminth RFamide peptides on muscle-strip preparations ofFasciola hepatica(Trematoda: Digenea)
Authors: Marks N. J. , Johnson S. , Maule A. G. , Halton D. W. , Shaw C. , Geary T. G. , Moore S. , Thompson D. P.
Published: June 2009

The effects of each of the known platyhelminth neuropeptides were determined on muscle-strip preparations from the liver fluke,Fasciola hepatica. The activity of synthetic replicates of the C-terminal nonapeptide of neuropeptide F (NPF9,Moniezia expansa), and the FMRFamide-related peptides (FaRPs), GNFFRFamide, RYIRFamide, GYIRFamide and YIRFamide, were examined. Muscle-strip activity was recorded from 1 mm segments of muscle prepared from 28 to 32-day-old worms, using a photo-optic transducer system. None of the peptides (≤10 μM) altered baseline tension significantly; however, each of the peptides increased the amplitude and frequency of muscle contraction. The threshold for activity of each of the peptides examined was, respectively, 1 nM (RYIRFamide), 0·3 μM (GYIRFamide and YIRFamide), and 10 μM (GNFFRFamide and NPF9). All of the effects were reversible and repeatable, following wash-out. Muscle-strip integrity was tested following experimentation, using arecoline (10 μM) and high-K+bathing medium (90 mM K+).
Primary and secondary infections of the domestic chicken with Trichostrongylus tenuis (Nematoda), a parasite of red grouse, with observations on the effect on the caecal mucosa
Authors: Watson H. , Lee D. L. , Hudson P. J.
Published: June 2009

The course of primary and secondary infections with Trichostrongylus tenuis in the domestic chicken was investigated. Primary infections were established after the administration of single and trickle doses of infective-stage larvae. The worm burden in the caeca was highest after a single dose of 500 infective-stage larvae; this gave a mean of 87 nematodes per bird on days 8–9 of infection, 20 nematodes on day 14 and 0 on day 28 of infection. Following trickle doses of 60, 100, 200, 300, 400 or 500 infective-stage larvae, there was a rise and then a fall in nematode egg output in all groups. In chickens given a primary dose of 500 infective-stage larvae followed 30 days later by a single secondary dose of 500 infective-stage larvae, the mean worm burden during the secondary infection rose to 57 nematodes on day 9 of infection and then fell rapidly to 18 nematodes on day 15 and to 2 on day 30. Scanning electron microscopy showed changes in the caeca of infected birds, with the caecal surface being covered in a layer of mucus from 12 days after infection. Balls of blood-stained mucus containing nematodes were observed in the caecal droppings from day 9 of infection onwards. It is concluded that chickens rapidly expel an established infection of T. tenuis, unlike the normal host, the red grouse.
Speciation of cestoda. Evidence for two sibling species in the complex Bothrimonus nylandicus (Schneider 1902) (Cestoda: Cyathocephalidea)
Authors: Renaud F. , Gabrion C.
Published: June 2009

Using biochemical genetic methods, we have distinguished 2 sibling species in the complex Bothrimonus nylandicus (Schneider, 1902), which infest 2 congeneric species of sole (Solea lascaris and Solea impar) on European coasts (Atlantic and Mediterranean). Neither of the parasite species is specific for either of the sole species, but one of them is present all year round, whereas the other is absent in the autumn and winter and only appears in the spring, subsequently disappearing at the end of the summer. Only S. impar lives in the Mediterranean, and is equally infested by both cestodes, whereas both species occur in the Atlantic and each of them is preferentially infested by 1 species of cestode. The shortness of the adult stage of the parasite in the definitive host and the presence of 2 life-cycles associated with competition between the 2 hosts in the Atlantic could be responsible for the biological differences observed and for maintaining the sibling species in sympatry.
Cysteine metabolism in the cestodeHymenolepis diminuta
Authors: Gomez-Bautista M. , Barrett J.
Published: June 2009

The major pathways for cysteine catabolism inHymenolepis diminutahave been investigated. The parasite has an active cystathionine-β-synthase and, as in other tissues, this enzyme has a wide substrate specificity. However, the enzyme fromH. diminutadiffers significantly from the mammalian enzyme in showing a high serine sulphydrase activity and a high serine lyase activity. There was only low γ-cystathionase activity inH. diminutaand again the enzyme showed a range of substrate specificities. Cysteine aminotransferase activity was readily demonstrated in the tapeworm, but there was no evidence for 3-mercaptopyruvate sulphotransferase activity. An oxidative pathway for cysteine catabolism inH. diminutawas shown by the presence of cysteine dioxygenase and cysteine sulphinate transaminase. The properties of the helminth cysteine dioxygenase were very similar to those of rat liver.H. diminutawas able to reduce cystine to cysteine via a glutathione-cysteine transhydrogenase system.
A quick, simple method for purifying Leishmania mexicana amastigotes in large numbers
Authors: Hart D. T. , Vickerman K. , Coombs G. H.
Published: June 2009

A rapid method for the bulk isolation of purified Leishmania mexicana mexicana amastigotes from parasite-induced lesions in experimentally infected mice is described. The procedure includes purification steps based on differences in net cell charge, lysis susceptibility and buoyant density between parasite and host cells. Yields of up to 2 × 1010 untransformed amastigotes with minimal contamination with host cells and cell debris can be obtained. At least 90 % of the purified amastigotes are viable as judged by light and electron microscopy, the staining of their lysosomes with acridine orange, their ability to transform to promastigotes and their infectivity to macrophages in vivo and in vitro.
Influence of variation in host strain and parasite isolate on inflammatory and antibody responses toTrichinella spiralisin mice
Authors: Goyal P. K. , Wakelin D.
Published: June 2009

Variation in the immunogenicity of 3 isolates ofTrichinella spiraliswas assessed by the parameters of adult worm recovery, mast cell, eosinophil and antibody responses in mice of defined response phenotype. The levels of the protective, inflammatory and immune responses induced by infection differed between the isolates. Isolates showed considerable variation in the capacity to elicit mast cell and eosinophil responses. All induced increases in parasite-specific antibody, levels of total (IgGAM) antibody and of IgM and IgG isotypes rose steadily after infection, but there were significant differences in levels of response. The IgGAM response was correlated with the number of worms present, i.e. the greatest response was seen in low responder (C57BL/10) mice infected with the longest-surviving isolates. All isolates elicited specific IgG1 and IgG2a antibodies after infection, although, again, there were isolate-specific differences in the levels and kinetics of response. Levels of these isotypes were always higher, although not significantly so, in high-responder NIH mice. Low-responder mice showed higher IgE serum levels than high-responder mice after infection, one isolate giving much higher IgE values than the other two.
Rickettsia-like organisms and chitinase production in relation to transmission of trypanosomes by tsetse flies
Authors: Welburn S. C. , Arnold K. , Maudlin I. , Gooday G. W.
Published: June 2009

Rickettsia-like organisms (RLO) from tsetse midguts and mosquito cell cultures showed high levels of endochitinase activity. A line of Glossina morsitans morsitans highly susceptible to midgut trypanosome infection and with high incidence of RLO infection showed significantly greater chitinolytic activity than G. austeni which had low RLO incidence and were correspondingly refractory to midgut infection. Midgut infection rates of Trypanosoma brucei rhodesiense in G. m. morsitans showed a dose-related increase when flies were fed N-acetyl-D-glucosamine (GlcNAc) in the infective meal and for 4 subsequent days. A model is proposed for susceptibility to trypanosome infection based on the generation of GlcNAc by RLO endochitinase activity in tsetse pupae inhibiting midgut lectin in teneral flies.
Phylogenetic affinities of Acanthocephala: an assessment of ultrastructural evidence
Authors: Whitfield P. J.
Published: June 2009

The phylogenetic relationships of the Acanthocephala are reviewed in the light of recent ultrastructural evidence. Comparisons of spermatozoan ultrastructure suggest that the Acanthocephala cannot be closely related to the Platyhelminthes and that the similarities which exist between cestodes and acanthocephalans are the result of convergence. Similarities in the spermatozoan ultrastructure of acanthocephalans, rotifers, nematomorphs and nematodes probably have a phylogenetic significance and suggest that the acanthocephalans have a close common ancestor with some at least of the Aschelminthes. The case for this affinity is strengthened by ultrastructural evidence concerning the body walls and muscles of acanthocephalans, nematodes and rotifers.

I am indebted to Professor D. R. Arthur and Professor F. R. Whatley at King's College, London, for the provision of facilities. The work reported in this paper was undertaken during the tenure of a Research Fellowship from the Nuffield Foundation.
Distribution of schistosome genetic diversity within naturally infected Rattus rattus detected by RAPD markers
Authors: Barral V. , Morand S. , Pointier J. P. , Théron A.
Published: June 2009

Random amplified polymorphic DNA markers (RAPD) were used to visualize the genetic diversity within and between infrapopulations of Schistosoma mansoni recovered from the natural vertebrate host, Rattus rattus, trapped at an insular Guadeloupean focus. Phenotypes were characterized by the sex of the parasites and by 8 polymorphic markers generated by 3 primers. Among the 212 parasite individuals recovered from 10 infected rats, 78 genotypes were characterized. All the hosts naturally infected harboured multiple parasite genotypes with a maximum diversity of 28 genotypes/host. Phenotypic and genotypic diversity calculated by Shannon-Wiener's indices and Lynch and Milligan's estimators respectively is, on average, greater within than between hosts. Considering the very low snail infection rates observed in this focus and the rapid turnover of the vertebrate hosts, our results suggest that the high mobility of the vertebrate host and/or plurimiracidial snail infections could be factors responsible for parasite genetic diversity within hosts.
Adhesion of parasitized red blood cells to cultured endothelial cells: a flow-based study of isolates from Gambian children with falciparum malaria
Authors: Cooke B. M. , Morris-Jones S. , Greenwood B. M. , Nash G. B.
Published: June 2009

Adhesion of parasitized red blood cells to vascular endothelium is thought to play an important role in the development of the ischaemic complications associated with severe falciparum malaria. Using a novel, flow-based assay, we have investigated the adhesion of parasitized red blood cells to formalin-fixed human umbilical vein endothelial cells (HUVEC), for isolates obtained from 32 Gambian subjects with mild or severe falciparum malaria. Red cells infected with wild strains ofPlasmodium falciparumwere able to adhere to HUVEC under physiologically relevant flow conditions, but the level of adhesion was highly variable, ranging from 1 to 688 adherent cells per mm2of HUVEC. Within isolates, some adherent parasitized cells remained stationary, whilst other formed less stable interactions and rolled slowly over the cell surface. There was no significant difference in adhesion of parasitized cells between isolates obtained from mild or severe cases of malaria, although a subset of isolates did show very high levels of adhesion. The results suggest that there is not a simple relationship between the adhesion of parasitized cells to cultured endothelial cells (presumably via the receptor ICAM-1) and the clinical severity of the disease, although variation in microvascular adhesionin vivomay still be a determinant of ischaemic complications.
Genetic structure of Trypanosoma cruzi populations from Argentina estimated from enzyme polymorphism
Authors: De Luca D'oro G. M. , Gardenal C. N. , Perret B. , Crisci J. V. , Montamat E. E.
Published: June 2009

Isolates of Trypanosoma cruzi from human patients, domestic and sylvatic animals and vector insects were obtained in different areas of Argentina. Electrophoretic patterns of enzymes from extracts of 95 isolates were analysed. On the basis of zymograms providing information on 10 loci, 12 zymodemes are described according to their genotypes. Data presented show fixed heterozygosity, absence of segregation of genotypes, significant departures from Hardy–Weinberg equilibrium, and over-represented genotypes. This evidence supports the hypothesis that sexual reproduction is very restricted or absent in this parasite. The proportion of polymorphic loci is 80%. The expected mean heterozygosity per locus (He) is 0·43, while the observed value (Ho) is 0·24. Differences between these values may be explained by accepting a basically clonal structure for T. cruzi. The data matrix of 12 zymodemes using 28 characters was analysed using a Wagner parsimony algorithm. Two equally most parsimonious unrooted trees were generated; both have 39 steps. The results show clusters clearly separated according to the geographical origin of the stocks. There are some indications of some correlations between genetic composition of the parasite and the clinical picture of the infection in human patients.
Localization, turnover and conservation of gp15/400 in different stages ofBrugia malayi
Authors: Selkirk M. E. , Gregory W. F. , Jenkins R. E. , Maizels R. M.
Published: June 2009

The expression of a protein complex designated gp15/400, previously identified via extrinsic iodination of adultBrugia malayi, was examined by labelling all stages found in the mammalian host and immunoprecipitation with a specific antibody raised to a recombinant protein. In this way, gp15/400 could be detected in L3, L4, adult worms and microfilariae recovered from jirds and labelled with Bolton–Hunter reagent. Metabolic labelling indicated that gp15/400 was released into culture medium when adult worms were maintainedin vitro, but at a rate slower than that of gp29, the major soluble cuticular glycoprotein. Immuno-electron microscopy showed that the protein complex was broadly distributed in different tissues, although it was not detectable in the cuticle of adult worms. Dense labelling was observed in the matrix of the basal laminae bordering the hypodermis, somatic musculature and oesophagus, and lower but significant labelling was seen in the cells overlying these extracellular matrices. Hybridization of genomic DNA with a cDNA probe encoding gp15/400 indicated that homologous genes were present inDirofilaria immitisandAcanthocheilonema viteae. The failure to detect related genes in non-filarial nematodes was presumed to be due to divergence beyond the practical limits of detection by nucleic acid probes, as antibody reagents showed that the protein cross-reacted immunologically with ABA-1, a major protein allergen from the body fluid ofAscaris.
A list of the parasitic Protozoa, Helminths and Arthropoda recorded from species of the Family Anatidae (Ducks, Geese and Swans)
Authors: Lapage Geoffrey
Published: June 2009

The following list, compiled during my tenure of a grant given by the Nuffield Foundation to the Wildfowl Trust, Slimbridge, Gloucestershire, records species of Protozoa, helminths and Arthropoda found in anatid birds, either by the authors of the papers listed in the References, or by others to whose work these authors refer. It will be seen that there are, after the names of all the parasites, numbers which indicate, by reference to the corresponding numbers in the References, the authors and publications in which the species concerned are recorded. ThusCotylurus brevis(142, 145*) means that this trematode was recorded fromAix galericulata, the Mandarin Duck, by Dubois (1953) and that Dubois & Rausch (1950a) reported an experimental infection of this duck with it.
The infection of the gullsLarus argentatusPont.,L. fuscus L.andL. marinusL. with Cestoda on the coast of Wales
Authors: Williams I. C. , Harris M. P.
Published: June 2009

An account is given of the incidence and intensity of infection of the gullsLarus argentatusPont.,L. fuscusL., andL. marinusL. with Cestoda on the coast of Wales. Eleven species of cestodes were found in the three species of gulls, nine inL. argentatus, eight inL. fuscusand six inL. marinus. Nine new host records and two new British records are listed.

The presence of the cestode parasites did not appear to be harmful to the birds.

Ecological and systematic notes are given on each of the cestode species. The basic cestode fauna ofL. argentatus, L. fuscusandL. marinuson the coast of Wales comprised three species, namelyTetrabothrius cylindraceus(Rud.),T. erostris(voennberg) andAnomotaenia micracantha(Krabbe).

The factors influencing the intensity and incidence of infection are considered and it is concluded that infection is determined mainly by the food and feeding habits of the host. It is shown that the number of cestodes per bird may be represented by a negative binomial distribution. There is some evidence to suggest that high intensities of infection were associated with high incidences. Three main stages in the development of the helminth-fauna of gulls are described and are related to the age and activity of the bird.

It is a pleasure to record our personal thanks to those to whom we are indebted, namely the Nature Conservancy and the West Wales Naturalists' Trust for permission to work on Skomer Island, to Mr D. R. Saunders, Warden of Skomer Island, for help in the collection of some of the Great Black-backed Gulls, to Mr P. Hope Jones who collected the gulls from Malltraeth, and to Professor J. G. Baer, Departement de Zoologie, Université de Neuchâtel, Professor W. E. Kershaw, Department of Parasitology and Entomology, University of Liverpool, and Mr Stephen Prudhoe, British Museum (Natural History), for the loan of specimens, and to Mr M. D. B. Burt, Department of Natural History, University of St Andrews, for identifying the specimens ofParicterotaenia paradoxa.

The participation of one of us (M. P. H.) in this work was made possible through the generous assistance of a D.S.I.R. research studentship, which is gratefully acknowledged.
The morphology of Lecithaster musteli sp.nov. (Digenea: Hemiuridae) from the intestine of Onos mustelus (L.) and a review of the genus Lecithaster Lühe, 1901
Authors: Srivastava L. P.
Published: June 2009

Lecithaster musteli sp.nov. from the five-bearded rockling, Onos mustelus (L.), at Mumbles Head, Swansea, is described and compared with other species of the genus.

The genus Lecithaster Lühe, 1901 is reviewed. An emended definition of the genus is given with keys, diagnostic features, and brief notes of the nine recognized species. L. gibbosus (Rud.) Lühe, 1901 is briefly redescribed.

L. intermedius Szidat, 1954 is considered to be a synonym of L. gibbosus (Rud.) Lühe, 1901.

I am deeply indebted to Dr B. L. James for his advice and indispensable assistance throughout the work and the preparation of this paper. I am also grateful to Professor E. W. Knight-Jones for his interest and for providing the working facilities, and to Mr S. Prudhoe, British Museum (Natural History), for his advice, for allowing me to examine slides of L. gibbosus and for the use of the library.
The life-history of Archigetes limnodrili (Yamaguti) (Cestoda: Caryophyllaeidae) and its development in the invertebrate host
Authors: Kennedy C. R.
Published: June 2009

The development of Archigetes limnodrili in species of Limnodrilus is described. There is no free-living larva and eggs are ingested by the tubificids. Growth and development is completed within the body cavity of the annelid, and egg liberation is accomplished by release of the parasite and decay of its body.

Breeding of A. limnodrili takes place throughout the year. In the localities investigated there was no evidence that a fish host was required in the life-cycle. Progenesis was the only type of development encountered in Britain.

A. limnodrili exhibits an unusual degree of host specificity, being found only in species of Limnodrilus. It is suggested that this is due to differences in the composition of the coelom or intestine of Limnodrilus compared to other genera.

The degree of infection in all localities is very low, and shows no regular seasonal variation. There is no similarity in the seasonal changes in different localities.

The relationship between the host and parasite is a stable one, and there is little mutual damage. Factors contributing to this stability are discussed.

The development of A. limnodrili is compared with that of other species of Archigetes, and the life-history discussed with particular reference to the phenomenon of progenesis.

I wish to thank Professor R. J. Pumphrey in whose Department this work was carried out, and Dr J. C. Chubb for his constant advice and criticism. I also wish to thank Dr K. H. Mann and the University of Reading for provision of specimens and permitting me the use of their facilities. The work was carried out during the tenure of a Nature Conservancy Research Studentship.
The action of serotonin (5-hydroxytryptamine)in vivoupon the microfilariae ofDirofilaria, Loaand five other species
Authors: Hawking Frank , Gammage Kenneth
Published: June 2009

When serotonin is injected intravenously into certain animals containing microfilariae it causes a sharp short rise in the microfilaria count in the blood, i.e. liberation of microfilariae from the lungs. This happens in the case ofDirofilaria immitis(in dog),D. repens(in dog),Loa loa(in drill),Edesonfilaria malayensisand another Dirofilaria-like microfilaria (in monkey),Monnigofilaria setariosa(in mongoose), andDipetalonema gracile(in squirrel monkey); but not withDip. witei(in gerbil) andLitomosoides cariniiin cotton rats.

This action (uponD. immitis) is not inhibited by atropine. Administration of reserpine, harmine or harmaline to dogs did not exert any definite action on the microfilaria count ofD. immitis. Serotonin had no obvious effect on thein vitroactivity of microfilariae ofL. loaorE. malayensis. Melatonin had no actionin vivoupon any of the above microfilariae.

The action of serotonin upon microfilariaein vivois similar to that of acetylcholine but it is not identical with it since the sensitivity ofDip. gracileandDip. witeito the two compounds is different.

Apparently this action is not involved in the production of the 24 h periodicity shown by many microfilariae. It may depend upon disturbance of the normal neuromuscular mechanisms of the microfilariae by which they are retained in the small vessels of the lungs.
The host-finding behaviour of the hen flea, Ceratophyllus gallinae (Schrank) (Siphonaptera)
Authors: Humphries David A.
Published: June 2009

Field and laboratory observations on the nature and sequence of the host-finding responses of the hen flea Ceratophyllus gallinae are described. The imago over-winters within the cocoon. Tactile stimuli and a rise in temperature initiate emergence. Emigration from the nest is delayed for a few days by a negatively phototactic response, and begins when this becomes positive. The fleas are negatively geotactic and disperse upwards into the vegetation. Eventually they take up a characteristic posture, oriented towards the light. Jumping is elicited when the light intensity is suddenly reduced, and it is suggested that this enables the fleas to reach their avian host. Those fleas whose jump misses the host fall and form a secondary distribution on the ground. The readiness to jump rises during the first few days after cocoon emergence, then falls again, the rate of fall apparently being partly determined by water loss.

The author is much indebted to the Hon. Miriam Rothschild and Drs E. T. Burtt and M. J. Cotton for valuable advice, and to C. R. Brannigan for a critical discussion of the manuscript. The main part of the research was carried out during tenure of a post-graduate studentship provided by the Department of Scientific and Industrial Research.
The bladder ofCysticercus fasciolaris: electron microscopy and carbohydrate content
Authors: Nieland M. L. , Weinbach E. C.
Published: June 2009

Morphological features of the bladder wall ofCysticercus fasciolarisand carbohydrate analysis of the contained fluid are described. The bladder fluid was found to have a higher concentration of glucose than the plasma of the respective host animal. The bladder wall has a prominent duct system with numerous cytoplasmic extensions and interconnections. It is suggested that the bladder may function in the nutrition of the developing cysticercus by providing a reservoir of raw material which may be utilized by the growing strobila.

The authors wish to thank Dr Theodor von Brand for many helpful discussions, and Dr Harley G. Sheffield and Mr Ned M. Etherington for their advice and technical assistance in the preparation of the electron micrographs.
Observations on the morphology and life-cycle of Paucivitellosus fragilis Coil, Reid & Kuntz, 1965 (Trematoda: Bivesiculidae).
Authors: Pearson J. C.
Published: June 2009

Paucivitellosus fragilis i sredescribed from the blenny, Salarias meleagris, found on beach-rock intertidally at Heron Island, Great Barrier Reef. The adult was also found in the mullet, Mugil cephalus and Crenimugil crenilabis at Heron Island, and Liza argentea at Brisbane.

Paucivitellosus differs from Bivesicula, Bivesiculoides and Treptodemus in having: (i) the vitellaria reduced to a single follicle on each side, (ii) two primary loops in the uterus, (iii) fully embryonated eggs in the terminal coils of the uterus, and (iv) the cirrus pouch orientated dorso-ventrally. The diagnosis of the family Bivesiculidae is emended.

The molluscan host at Heron Island is Cerithium penthusarus, in which cercariae develop in ‘fork-tailed’ rediae.

The cercaria is furcocystocercous and differs from known bivesiculid cercariae in having a protrusible glandular fold, within the mouth of the invaginated caudal chamber, by which the cercaria attaches to objects.

Evidence is presented for the view that the life-cycle is a two-host one, that there is no metacercarial stage, and that the cercaria is ingested by browsing.

I should like to thank the Great Barrier Reef Committee for the use of facilities at the Heron Island Research Station, where the field work was carried out. Professor H. W. Manter, University of Nebraska, generously donated all of the bivesiculid material that he collected in Australia, including adults of Paucivitellosus fragilis from the warty-lipped and sea mullet. Mr N. Milward and Mr H. Choat, of the Department of Zoology, kindly identified the fish hosts and furnished information on their feeding habits, and Dr D. F. McMichael, of the Australian Museum, kindly identified the snail host. Dr W. H. Coil, University of Kansas, kindly lent three paratypes (?) of P. fragilis. Thanks are also due to Mr R. J. Ballantyne for his able technical assistance in the collection and preparation of material.

The work was supported by a research grant from the University of Queensland.
Studies on Myxidium oviforme, a myxosporidan parasite of Irish salmon, Salmo salar
Authors: Walliker D.
Published: June 2009

Myxidium oviforme is described from Irish salmon Salmo salar. Its close relationship with M. folium, M. moxostomatis and M. aplodinoti, and its possible economic importance are discussed.

Attempts to establish infections of M. oviforme in young, parasite-free salmon are described, and the reasons for their negative results discussed.

This work was carried out during the tenure of a Medical Research Council Scholarship for Training in Research Methods between October 1964 and September 1966, and forms part of a thesis submitted for the Ph.D. Degree of the University of London. Grateful acknowledgement is due to Dr J. G. Ross and Dr G. Lawson of the Veterinary Research Division of the Ministry of Agriculture for Northern Ireland for information on salmon infections in Ireland, to the Ministry of Agriculture and Fisheries for the provision of young salmon, and to Messrs Barnetts of Frying Pan Alley Ltd., London, for the provision of salmon livers.
Observations on the biology ofCaraphractus cinctusWalker (Hymenoptera: Mymaridae), a parasitoid of the eggs of Dytiscidae (Coleoptera). 2. Immature stages and seasonal history with a review of Mymarid larvae
Authors: Jackson Dorothy J.
Published: June 2009

The immature stages ofCaraphractus cinctusWalker are described.

Four larval stages have been observed which may correspond to three or four instars. In no stage have mandibles been observed.

The first-instar larva is elongated and active. In the second-instar oral lobes are present. In the next stage the larva becomes shapeless and rather transparent. In the last stage the wall of the mid-gut shows conspicuous opaque spots which consist of single cells containing spherical concretions, probably the products of excretion.

These concretions later become free in the gut of the pupa and are discharged in the meconium when the imago emerges from the host egg.

The effects of parasitism on the host eggs of different ages is discussed. In newly laid host eggs all the contents are consumed by the parasitic larvae. In advanced eggs ofAgabusthe egg ofCaraphractusis laid in the mid-gut of the host embryo where the parasitic larva develops, the hard parts of the host larva remaining intact. Parasitism in advanced eggs ofDytiscusis rarely successful.

The larvae of other Mymaridae are discussed and their main features compared. The first-instar larva ofCaraphractusdoes not correspond to any of the previously described types of mymarid larvae.

The seasonal history is described, with the sequence of hosts parasitized throughout the year. From four to six generations ofCaraphractushave been bred indoors during the year. The winter is passed as a diapausing prepupa. In some cases diapause may be prolonged. Fertility is high: 121 imagines have been bred from one female ofCaraphractus.

I have much pleasure in acknowledging my gratitude to the late Dr W. D. Hincks for his kindness in reading the typescript of this paper: the comments by such a well-known authority on Mymaridae have been most valuable. I am very grateful to Mr O. Bakkendorf for allowing me to reproduce several of his figures of Mymarid larvae from the valuable work he devoted to the biology of Danish hymenopterous egg-parasites. I am also grateful to Miss B. A. Trott of the Commonwealth Institute of Entomology for the help she has so kindly given me with references.
Studies on the resistance of rats to the nematode Nippostrongylus muris (Yokogawa, 1920). II. Different routes of immunization and test infection
Authors: Hunter G. C. , Leigh L. C.
Published: June 2009

Rats were given immunizing doses of N. muris larvae by three different routes: orally and intraperitoneally and through the skin. The immunized rats survived a test infection which was lethal for non-immune rats. Only the rats immunized by the skin route showed skin sensitivity.
The protozoa occurring in the hind-gut of cockroaches. I. Responses to changes in environment
Authors: Hoyte H. M. D.
Published: June 2009

Records of non-sporozoan Protozoa occurring in the hind-gut of cockroaches are summarized.

The Protozoa studied were the three flagellatesLophomonas striata, L. blattarum, Monocercomonoides orthopterorum; the rhizopodEndamoeba blattae, and the ciliateNyctotherus ovalis, in the cockroachesPeriplaneta americana, P. australasiae, Blatta orientalis, Blattella germanicaandBlaberus giganteus.

Specimens ofBlattaandPeriplaneta americanawere maintained at 37° and 25°C. under extreme conditions of humidity. Maximum humidity enabled the host, and theNyctotheruswhich it harboured to survive for a longer time. The results of the experiments indicated that the well-being of the protozoan parasites is closely linked to that of the host.

Periplaneta americana, Blatta, BlatellaandBlaberuswere subjected to pure oxygen at 3½ atmospheres pressure and the effect on the Protozoa observed. The flagellates were killed first, thenEndamoebaand lastlyNyctotherus. They survived inBlattafor a longer time than inPeriplaneta; andNyctotherusinBlaberusandBlattellasometimes survived the hosts. The hosts appeared to act as a barrier against poisoning by oxygen, and the strength of the barrier varied in the different species of cockroaches.

NymphalPeriplanetaorBlattawhich were about to moult underwent a period of self-starvation which lasted for up to 10 days. The period was terminated by the moult: at this time, the little food that was in the gut was very dry. All species of Protozoa could survive these conditions, butNyctotherusseemed to be the most hardy. The main mass of ciliates seemed to be nearer to the anus than in the non-moulting cockroach. Many of the ciliates were often clumped together into a ‘raspberry’. The bodies of the individual ciliates were more spherical than usual, but those in the ‘raspberry’ were moulded into polygonal shapes. The macronucleus underwent a change in form which revealed that its basic structure is that of a folded sheet.

The changes were reversed within 24 hr. They could not be induced by experimentally imposed conditions of starvation or dehydration of the hind-gut. The changes inNyctotherus ovalisare contrasted with the sexual stages occurring inN. cordiformisand in the Protozoa ofCryptocercus.

This work was done during the tenure of a Research Studentship awarded by the Agricultural Research Council. I am deeply indebted to Dr P. Tate for his encouragement and counsel at all stages of the work. I wish to thank Drs J. Barker and E. R. Turner, of the Cambridge University Botany School, for the loan of the apparatus used in subjecting cockroaches to oxygen under pressure, and Mr A. C. Bloy, of the Zoology Department, for gifts of cockroaches. I am most grateful to Mrs E. F. M. Hawkins and Mr B. H. Baker for technical assistance.
Studies on ovarian development in tsetse flies (Glossina, Diptera)
Authors: Saunders D. S.
Published: June 2009

Five species of Glossina (G. morsitans, G. pallidipes, G. austeni, G. brevipalpis and G. palpalis) have ovaries containing two polytrophic ovarioles, each of which contains a single egg follicle. In all these species the right ovary is more highly developed than the left at emergence. This type of ovary is probably common to all species of Glossina.

The development of the egg follicles in G. morsitans pupae is described. It is shown that the cycle of development whereby eggs are produced alternately from right and left ovaries is established during pupal development and that some yolk deposition has occurred in follicle A (right ovary) and follicle C (left ovary) before the fly emerges from the puparium.

In G. morsitans, it is shown that the size of the egg follicles in newly emerged flies is correlated with the size (R.D.W.) of the fly, larger females having more yolk laid down in their follicles before emergence. This is probably correlated with the state of reserves in the fat body. It is also shown that there is a seasonal variation in follicle size in newly emerged flies, this variation is probably correlated with variations in temperature acting upon wild females during pregnancy and upon the pupae, as temperature is known to affect both size and fat content of wild tsetse flies.
The effect of the synthetic plant-growth substance, 2, 4-dichlorophenoxyacetic acid, on the host–parasite relationships of some plant-parasitic nematodes in monoxenic callus culture
Authors: Webster J. M. , Lowe D.
Published: June 2009

Some callus tissues induced by 2,4–D and derived from plants resistant to plant-parasitic nematodes lost their resistance to the nematodes. Red clover callus supported a large population of A. ritzemabosi, whereas red clover seedlings did not. Six races of D. dipsaci were cultured on lucerne and red clover callus tissues and reproduced rapidly, although races usually multiplied more on callus from susceptible than from resistant plants. A. ritzemabosi, normally only a foliage parasite, reproduced equally well in stem and root callus. H. rostochiensis did not reproduce in callus culture.

Nematodes multiplied most in callus that grew fastest; both reproduction of A. ritzemabosi and the growth of callus were greatest with 0.125 mg/1 of 2,4–D. Reproduction was inhibited by 5.0 mg/100 ml of 2,4–D. 2,4–D influenced nematode reproduction indirectly by making callus, which provides a better environment for nematode feeding and reproduction.

Nematode extracts added to an agar medium caused callus formation on red clover seedlings and nematodes feeding on these tissues reproduced faster than on normal seedlings. Hence, the substances secreted by a nematode into a plant may act on the tissues in a manner similar to 2,4–D. The host–parasite relationship is probably partially controlled by the host's plant-growth substances and the effect on them of the nematode's secretions.

We thank Mr C. T. Drakes for assistance, and Mr K. Smith of Imperial Chemical Industries for advice with the initial callus culture.