bluuebunny/crossref_metadata_2025_split huggingface dataset:
The number of niches in intestinal helminth communities of Anguilla anguilla: are there enough spaces for parasites?
Authors: Kennedy C. R. , Guégan J.-F. 
Published: June 2009

SUMMARYThe suggestion that there may be a limit to the number of niches available to helminth species in the intestine of Anguilla anguilla was investigated by examining the frequency distributions of the number of helminth species per eel and the relationships between maximum and mean infracommunity richness and component community richness in 1 locality over 17 years and in 64 localities throughout Ireland and England. The maximum number of species per eel did not exceed 4 in the 1 locality, or 3 in the 64 localities. In both the single and the several localities, the relationship between maximum and mean infracommunity richness and component community richness was curvilinear and best described by a power or polynomial function. This was interpreted to mean that infracommunity richness became increasingly independent of component community richness, and that infracommunities were saturated at values well below the higher level of helminth richness immediately available for colonization i.e. component community richness. It is argued that these findings cannot be explained by supply-side ecology, pool exhaustion or transmission rates, but only by infracommunity processes acting to impose a fixed limit to the number of species in an infracommunity. Most infracommunities are species poor, and the limiting factors will only operate as species richness rises to determine a maximum. Acceptance of a limit to the number of niches available also resolves the apparent inconsistency between the occurrence and importance of interspecific competition and the nature of isolationist communities.
The precise estimation of the effects of extrinsic factors on the egg production and egg hatch rates of ixodid ticks
Authors: Sutherst R. W. 
Published: June 2009

The aim of the present contribution has been to draw attention to the technique of covariance analysis in the study of factors influencing the oviposition of ixodid ticks.The example given as an illustration shows the high degree of sensitivity of the technique and its effectiveness in removing the bias due to the sample differences in the mean female weights of different treatment groups. This bias has not been removed in any published work on egg-production studies of ticks, so preventing precise comparisons of different conditions to be made.My thanks are due to Dr D. E. Moorhouse for helpful advice and to the Australian Meat Research Committee for generous financial support. The cooperation and assistance of Mr W. J. Roulston and his staff of the Division of Entomology, C.S.I.R.O. is gratefully acknowledged.
Nematode parasites of Oceanica
Authors: Schmidt Gerald D. , Kuntz Robert E. 
Published: June 2009

Camallanus marinus sp.nov. is described from eleven specimens recovered from a variety of marine fishes. It is the only species in Camallanus s.s. with a single spicule. Spinitectus palawanensis sp.nov. is described from two males and one female found in a scombrid fish. It is characterized by having 12–17 rings of 60–65 spines, a spicule ratio of 5:1, and ten pairs of caudal papillae. Cucullanus lutjani, sp.nov. is described from two specimens from lutjanid fishes. It is distinct in lacking a preanal sucker, in possessing a gubernaculum and eight pairs of cloacal papillae.Oceanicucullanus padfica gen. et sp.nov. is described from two specimens found in cyprinid fish. It is most similar to Indocucullanus, differing from it in the absence of a gubernaculum, and in possessing three pairs of teeth in the radii of the oesophagus. Philometra (Philometra) lateolabracis Yamaguti, 1935; Terranova sp.; and Procamallanus spp. are reported for the first time in the Philippines.We wish to thank Dr D. S. Rabor, Silliman University, Damageute, Negros Oriental, Republic of the Philippines, for general support in field activities, and Dr Loren Wood, Curator of Fishes, and Dr Robert F. Inger, Curator of Reptiles, Chicago Museum of Natural History, for identification of hosts. Acknowledgement is also made to Dr Betty June Myers for technical assistance and advice in handling materials.
Physiological studies on trematodes: calcium, magnesium and phosphorus content
Authors: Goil Madan M. 
Published: June 2009

1. Four trematodes,Gastrothylax crumenifer, Cotylophoron cotylophorum, Paramphistomum explanatumandFasciola giganticahave been used for quantitative analysis of their inorganic constituents.2. Calcium, magnesium and phosphorus content have been determined.3. All the four trematodes contain large amounts of phosphorus (0·61–1·05%); but the amounts of calcium (0·025–0·045%) and magnesium (0·029–0·065 %) are small.
A survey of the endoparasites of the Red Kangaroo Megaleia rufa (Desmarest)
Authors: Mykytowycz R. 
Published: June 2009

A survey of endoparasites of the Red Kangaroo (Megaleia rufa (Desmarest)) has been carried out in three geographically distinct areas of south-eastern Australia.During a period covering 22 months, 464 kangaroos of different sexes and ages were collected. Alimentary canals and tracheae of all of them and blood and organ smears from 333 were examined for parasites.A list of endoparasites of the Red Kangaroo encountered during the study and of others reported earlier is given. This includes three species of blood protozoa, two species of coccidia (Eimeria spp.), two species of cestode and twenty-one species of nematodes.The numbers of some nematode species are analysed in relation to season, sex of host and age of host as expressed by length of tibia.Two different patterns of age susceptibility of the Red Kangaroo to nematodes are recorded and it is suggested that these may be dependent upon the presence or absence of direct contact of the parasite with host tissue.Distribution of nematodes in the stomach of the Red Kangaroo has been studied. Different species were found to occupy separate niches within the stomach.A statistical test aimed at showing the correlation between severity of infection with some nematodes and condition of host expressed by the ratio: body weight — stomach content/tibia length showed only a very weak negative correlation.Alimentary canals of 100 sheep and thirty-five wild rabbits sampled simultaneously in the same area were found to be infected with only small numbers of worms.No parasites injurious to domestic stock were found in the kangaroos examined.
Remarks on the diplomastigine flagellates from the intestine of fishes
Authors: Kulda Jaroslav , Lom Jiří 
Published: June 2009

In the intestine of freshwater fishes, two morphologically different types of diplomastigine flagellates have so far been found to exist: Hexamita salmonis (Moore, 1920) specific for fishes, and Spironucleus elegans Lavier, 1936, identical with the flagellate from amphibia.The identity of the Spironucleus from fishes and amphibia has been demonstrated by infecting Pterophyllum scalare with flagellates from newts per os, per rectum and with contaminated food.A redescription of motile stages of both Hexamita salmonis and Spironucleus elegans is presented, together with a list of existing findings of fish diplomastigines, and a brief discussion.
Trypanosome sociology and antigenic variation
Authors: Vickerman K. 
Published: June 2009

SUMMARYSurvival of the trypanosome (Trypanosoma brucei) population in the mammalian body depends upon paced stimulation of the host's humoral immune response by different antigenic variants and serial sacrifice of the dominant variant (homotype) so that minority variants (heterotypes) can continue the infection and each become a homotype in its turn. New variants are generated by a spontaneous switch in gene expression so that the trypanosome puts on a surface coat of a glycoprotein differing in antigenic specificity from its predecessor. Homotypes appear in a characteristic order for a given trypanosome clone but what determines this order and the pacing of homotype generation so that the trypanosome does not quickly exhaust its repertoire of variable antigens, is not clear. The tendency of some genes to be expressed more frequently than others may reflect the location within the genome and mode of expression of the genes concerned and may influence homotype succession. Differences in the doubling time of different variants or in the rate at which trypanosomes belonging to a particular variant differentiate into non-dividing (vector infective) stumpy forms have also been invoked to explain how a heterotype's growth characteristics may determine when it becomes a homotype. Recent estimations of the frequency of variable antigen switching in trypanosome populations after transmission through the tsetse fly vector, however, suggest a much higher figure (0·97–2·2 × 10−3switches per cell per generation) than that obtained for syringe-passed infections (10−5–10−7switches per cell per generation) and it seems probable that most of the variable antigen genes are expressed as minority variable antigen types very early in the infection. Instability of expression is a feature of trypanosome clones derived from infective tsetse salivary gland (metacyclic) trypanosomes and it is suggested that high switching rates in tsetse-transmitted infections may delay the growth of certain variants to homotype status until later in the infection.
The ecology of the sheep tick, Ixodes ricinus L. Host relationships of the tick: Part 2. Observations on hill and moorland grazings in northern England
Authors: Milne A. 
Published: June 2009

Although three other Ixodes species were found, Ixodes ricinus L., when it occurs, is by far the most important tick parasite of wild and domestic animals on hill and moorland grazings in northern England. In the following, ‘tick’ or ‘ticks’ refer to I. ricinus.The previous list of British mammal hosts, wild and domestic, to the tick (any stage) is largely confirmed, and increased approximately from twenty-three to twenty-nine species; and birds, similarly, from twenty-one to thirty-nine species. The preponderance of small mammals and birds among the twenty-four new-recorded host species confirms the impression that previous workers tended to confine their attentions to the larger animals. The host list is still incomplete, and the suggestion that the tick will parasitize any bird or mammal it may meet is strongly reinforced.No host occurs below the reptile level among vertebrates; and among British reptiles, only the common lizard is a host—rarely. There appear to be no hosts among invertebrates.All the farm and domestic mammals from horse down to cat are hosts to female ticks, but poultry have never been recorded—probably because they do not much frequent the tick-infested pastures.Only the larger wild mammals and birds are hosts to female ticks. In northern England these include eight mammals and three birds. For Britain as a whole two other mammals are known, while a further four mammals and one bird are likely hosts.With or without the inclusion of domestic animals, proportionately more mammal than bird species are hosts to female ticks. This is because there are more mammal than bird species large enough to be hosts.All the recorded British hosts, except shrew and possibly mole, are hosts in some degree to nymphs, and all, without exception, are hosts to larvae.A certain amount of self-deticking is practised by birds, and very probably by some of the smaller mammals. Birds never have ticks attached within beak-reach.
The phylogeny of the nematode family Metastrongylidae Leiper, [1909]: a correlation of host and symbiote evolution
Authors: Dougherty Ellsworth C. 
Published: June 2009

1. History of the classification of the family Metastrongylidae is briefly reviewed.2. The probable origin of the family is discussed. It is believed that the metastrongylids arose, in common with the family Strongylidae, from a primitive group of eustomatous, cloacinin-like, gastro-intestinal strongylines that were symbiotic with an ancestral mammalian group, possibly the pantotheres. One group of these symbiotes established itself in the mammalian respiratory tract and originated the metastrongylid line.3. The family Trichostrongylidae is regarded as of common origin with the family Ancylostomatidae from eustomatous ancestors. Thus meiostomy in the metastrongylids and trichostrongylids is convergent.4. The Metastrongylidae consist of three main lines, each characteristic of a placentate order: the Filaroidinae in the Carnivora, the Pseudaliinae in the Cetacea, and the Protostrongylinae in the Artiodactyla. These lines probably have evolved from a common ancestor, symbiotic with a host at the base of the carnivore-cetacean-ariodactyl radiation. Certain forms have become secondarily adapted to symbiosis with members of other placentate orders.5. Morphological and biological evidence is given for each of the foregoing phylogenetic conclusions.6. Metastrongylus Molin, 1861, is regarded as a relict genus. With it, in a subfamily Metastrongy-linae, is placed the genus Heterostrongylus Travassos, 1925.7. Heterostrongylus is represented by a single known species, H. heterostrongylus Travassos, 1925, from an opossum (order Marsupialia). Morphologically it is primitive with cloacinin-like cephalic features. In view of the phylogenetic status of its host it may well represent an ancestral type that has evolved along with the Marsupialia from a common ancestry with the other metastrongylids, probably in the panthotheres. As yet unknown lungworms of marsupials may shed light on this interesting point.8. Diagnoses are given for the family Metastrongylidae and its subfamilies; the twenty-two component genera are listed under the latter. New synonymies are made: Neometastrongylus Kreis, 1944, a synonym of Neostrongylus Gebauer, 1932; Neometastrongylus buechii Kreis, 1944, of Neostrongylus linearis (Marotel, 1913) Gebauer, 1932; and Otophocaenurus Skriabin, 1942, of Pharurus Leuckart, 1848. Otophocaenurus oserskoi Skriabin, 1942, becomes Pharurus oserskaiaae (Skriabin, 1942, n.emend.) n.comb.; Metathelazia massino becomes M. massinoi (Davtian in Skriabin, 1933, n.emend.) Dougherty, 1943.
The uptake of radioactive phosphorus from host tissues and fluids by nematode parasites
Authors: Rogers W. P. , Lazarus Marian 
Published: June 2009

1. Compared with the mammalian intestine, uterus and blood serum, the corresponding organs and perienteric fluid ofAscaris lumbricoideswere found to have a high phosphorus content. The muscle of the parasite, however, contained little more than half the phosphorus found in the mammalian muscle.2.A. lumbricoidestook up inorganic ortho-phosphate largely or exclusively through the alimentary tract. Small amounts were taken up by the cuticle and the lateral line system, but did not appear to pass on to other tissues.3.Nippostrongylus murisin the intestine of the rat took up radioactive phosphorus which had been injected into the host intramuscularly. When the host was dosedper osthe radioactivity appeared in the parasites at a lower concentration than in the host's small intestine.4.Ascaridia gallifailed to show any radio-activity when host birds were injected intravenously with inorganic orthophosphate containing P32. A sudden rise and fall in the radioactivity of the parasites were found when host birds were dosedper os.5. It is suggested that nematode parasites have a high demand for phosphate which they take up largelyper os. Ascaridia gallifeeds rapidly, but with poor phosphate absorption, on host gut contents.Nippostrongylus murisfeeds on host tissues. It is suggested that the different feeding habits ofN. murisandAscaridia gallimay have some relation to the efficacy of anthelmintics against these parasites.The authors are indebted to Dr M. Kamen and Dr E. Reinhard of Washington University, St Louis, for a gift of radioactive phosphorus. Thanks are also due to Mr E. Parrish and Mr L. Turk of the McMaster Laboratory for their capable assistance.
On the gregarineLankesteria culicis(Ross), 1898, from the mosquitoAëdes(Finlaya)geniculatus(Olivier)
Authors: Ganapati P. N. , Tate P. 
Published: June 2009

1. The morphology and life history of a gregarineLankesteria culicis(Ross), as it lives in the gut ofAëdes(Finlaya)geniculatus(Olivier), are described. The earlier stages are intra-epithelial in the fore and anterior mid-gut of the larvae. After a period of growth the trophozoites are liberated into the gut lumen where they attach themselves to the epithelium by a well-developed epimerite which functions as a sucker. Cyst formation and further stages in sporogony take place in the malpighian tubules when the larvae develop into the pupae. In the adult mosquito only ripe sporocysts are found, packed in the malpighian tubules and scattered in the hind-gut. The spores escape through the alimentary canal.2. The systematic position ofLankesteriais reviewed. In view of its true dicystid nature, combining both acephaline and cephaline features, it is suggested that its proper systematic position would be in the dicystid family Lecudinidae Kamm emend. Reichenow, 1929, which includes all forms intermediate in position between the monocystids and the true tricystids.
The structure of the adult and larval stages ofPlagiorchis (Multiglandularis) megalorchisn.nom. from the turkey and an experimental demonstration of the life history
Authors: Rees Gwendolen 
Published: June 2009

1. Large numbers ofPlagiorchis (M.) megalorchisn.nom. were found in the intestine of four turkey poults of a total of thirteen which had died on a farm in Radnorshire. Presumably the presence of the parasites was the cause of death.2. The anatomy of the adult worm is described.3. The first intermediate host of the parasite isLymnaea pereger, and the second intermediate host any of the following species of insect larvae:Chironomus ripariusMeigen,Culicoides stigmaMeigen,Culicoides nubeculosusMeigen andAnatopynia (Psectrotanypus) variusFabr.4. The larval stages of the worm are described.5. The life cycle has been demonstrated experimentally by the feeding of insect larvae containing encysted cercariae to turkey poults.6. The turkey is probably not the normal host ofPlagiorchis (M.) megalorchis. It is most likely that it occurs naturally in some species of wild bird, but this is not yet known.
β-ionone activates and bleaches visual pigment in salamander photoreceptors
Authors: ISAYAMA TOMOKI , McCABE ENGLAND S.L. , CROUCH R.K. , ZIMMERMAN A.L. , MAKINO C.L. 
Published: June 2009

AbstractVision begins with photoisomerization of 11-cis retinal to the all-trans conformation within the chromophore-binding pocket of opsin, leading to activation of a biochemical cascade. Release of all-trans retinal from the binding pocket curtails but does not fully quench the ability of opsin to activate transducin. All-trans retinal and some other analogs, such as β-ionone, enhance opsin’s activity, presumably on binding the empty chromophore-binding pocket. By recording from isolated salamander photoreceptors and from patches of rod outer segment membrane, we now show that high concentrations of β-ionone suppressed circulating current in dark-adapted green-sensitive rods by inhibiting the cyclic nucleotide-gated channels. There were also decreases in circulating current and flash sensitivity, and accelerated flash response kinetics in dark-adapted blue-sensitive (BS) rods and cones, and in ultraviolet-sensitive cones, at concentrations too low to inhibit the channels. These effects persisted in BS rods even after incubation with 9-cis retinal to ensure complete regeneration of their visual pigment. After long exposures to high concentrations of β-ionone, recovery was incomplete unless 9-cis retinal was given, indicating that visual pigment had been bleached. Therefore, we propose that β-ionone activates and bleaches some types of visual pigments, mimicking the effects of light.
The Opisthokonta and the Ecdysozoa may be clades: An update on Philip et al. (2005)
Authors: Prous Marko 
Published: June 2009

AbstractTo test the monophyly of Opisthokonta (animal-fungal clade) and Ecdysozoa (nematode-arthropod clade), Philip et al [Mol. Biol. Evol. 22: 1175–1184 (2005)] used sequence data from 10 eukaryotic genomes (an alveolate, a plant, two ascomycetous yeasts, a nematode, two dipterans, and three vertebrates). Strict criteria were used to select genes for phylogenetic analyses: single-gene families were identified and from these families, genes capable of recovering the uncontroversial parts of the phylogenetic tree (for example animal and vertebrate monophyly) were selected. Only five single-copy genes were found to be universally distributed across the analyzed taxa and capable of recovering all the uncontroversial parts of the tree. Phylogenetic analyses of those genes gave strong support for plant-animal grouping and the monophyly of Coelomata (vertebrate-arthropod grouping). Because numerous additional genome and EST projects have been completed since 2005, it is now possible to test the results of Philip et al using improved taxon sampling. Here, homologues of those five protein-coding genes (prefoldin 2, Tim22, U6 snRNP-associated protein, MAK16, and autophagocytosis protein) were obtained from sequence databases for additional taxa. Phylogenetic analyses of concatenation of those genes, using improved taxon sampling, recovered monophyly of Opisthokonta and Ecdysozoa, as well as Protostomia and Lophotrochozoa. These results again illustrate the importance of increased taxon sampling as shown in numerous previous studies using other datasets.
Sulfur-bound biomarkers of a Monterey shale and a Greenland lake sediment
Authors: Stern Joshua 
Published: June 2009

AbstractSeeking to reconstruct the biogeochemical processes that produced organic sulfur compounds in two unique depositional environments, we used the nickel boride desulfurization reaction to release hydrocarbons from sulfur-bound macromolecules not otherwise amenable to chromatographic analysis. We desulfurized two geochemical extracts: one sample is a Monterey shale of late Miocene age, and the other sample is a surface sediment from the Greenland lake Brayasø. Both samples contained organic sulfur compounds, but the Monterey shale was biologically and thermally modified after deposition. A comparison of the free and sulfur-bound hydrocarbons from each sample revealed a precursor-product relationship between tocopherol and pristane, for Monterey. Greenland’s composition may indicate that photochemical sulfurization occurs in the Brayasø oxic zone. We found that sulfurization may proceed at different rates for different compound families; for example, we did not see any sulfurized alkenones in Brayasø, but we found an abundance of sulfurized isoprenoids. Greenland’s relatively high overall desulfurization yield suggests that sulfurization in Brayasø occurs in under 40 years. Our Greenland findings suggest that photochemical sulfurization may be more widespread than previously thought, and that sulfurization might not interfere with alkenone paleotemperature reconstructions.