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1.
Four protozoan epizooites are found attached to the gills of Gammarus pulex collected from Rutland Water. The suctorian, Dendrocometes paradoxus, and the peritrichs, Epistylis sp. and Lagenophrys sp., are relatively abundant, but the chonotrich, Spirochona gemmipara is only occasionally found. SEM studies of various aspects of these protozoa are described. SEM has been useful in distinguishing between the two species of Lagenophrys found on Gammarus. L. ampulla is found on the gills and L. nassa is found on the limbs. The two species are distinguished by the differences in the structure of the loricastome. The relationship between the epizooites and their host is discussed briefly.  相似文献   

2.
The geographic distribution of three closely related Hyalomma species, namely Hyalomma (Euhyalomma) truncatum Koch, 1844, Hyalomma (Euhyalomma) albiparmatum Schulze, 1919 and Hyalomma (Euhyalomma) nitidum Schulze, 1919 is confined to Africa. A detailed comparison of all stages of development of the three taxa reveals that they possess many more shared than distinguishing characters. In fact differentiation between these species is based on single or dual qualitative characters on their adults. These are a conspicuous, ivory-coloured parma on H. (E.) albiparmatum males, and the absence or reduction in clarity of ivory-coloured bands on the leg segments of H. (E.) nitidum adults, as well as the shape of the external cuticular preatrial fold of the genital operculum of females of the latter species. The adults of all three species and the larva of H. (E.) truncatum are redescribed. The nymph of H. truncatum and the larva and nymph of H. (E.) albiparmatum and H. (E.) nitidum are described for the first time. Data on their geographic distributions and hosts are provided.  相似文献   

3.
The family Neckeraceae is composed of three distinct clades, of which two, i.e. the Neckera and Thamnobryum clades, are well defined. The third clade, consisting of species belonging to Caduciella, Curvicladium, Handeliobryum, Himantocladium, Homaliodendron, Hydrocryphaea, Neckera, Neckeropsis, Pinnatella, Shevockia and Taiwanobryum, is the focus of this study. Based on sequence data from the trnS-rps4-trnT-trnL-trnF plastid cluster and the rpl16 intron as well as from nuclear ITS1&2, the phylogenetic relationships of these genera are reconstructed. The nearest relatives of this clade are resolved shedding more light on the evolution of the family. The generic composition of the clade and its individual genera are discussed; polyphyly requires redefinition of Pinnatella, Neckeropsis and Homaliodendron. The positions of Touwia and Homalia within the family are addressed in an additional analysis based on more extensive sequence data, and the corresponding new combinations are made. Several further taxonomic changes are proposed, including Circulifolium gen. nov., comprising the former Homaliodendron exiguum and H. microdendron.  相似文献   

4.
This paper presents new species, combinations, national reports and host records for the South African rust fungi (Uredinales/Pucciniales). Endophyllum mpenjatiense on cf. Hibiscus sp. (Malvaceae), Phakopsora combretorum (anamorph Uredo combreticola) on the new host Combretum apiculatum (Combretaceae) and Uredo sekhukhunensis on Ziziphus mucronata (Rhamnaceae) are described as new species. Dietelia cardiospermi and E. metalasiae are proposed as new combinations to replace Aecidium cardiospermi on Cardiospermum halicacabum (Sapindaceae) and A. metalasiae on Metalasia spp. (Asteraceae), respectively. Four species are new records for South Africa: Crossopsora antidesmae-dioicae on Antidesma venosum (Euphorbiaceae), Phakopsora ziziphi-vulgaris on Z. mucronata, and Uromyces cypericola and Puccinia subcoronata, both on a new host, Cyperus albostriatus (Cyperaceae). The record of P. subcoronata is the first one from outside the New World. Puccinia scirpi is reported as a possible addition to the South African rust fungi. New host records and observations are presented for Pucciniastrum agrimoniae that is recorded on two new host genera and species, Cliffortia odorata and Leucosidea sericea (Rosaceae), Uromyces cypericola whose urediniospores are described for the first time, Phakopsora stratosa in that spermogonia and Uredo-like aecia were discovered, and for Sphaerophragmium dalbergiae in that characters of the urediniospores are re-evaluated. A lectotype is selected for Aecidium garckeanum and spermogonia are reported for this rust for the first time. The rust fungi of Ehrharta (Poaceae) are discussed and critically evaluated in the light of spore morphology and host species.  相似文献   

5.
Summary The sporocyst and metacercaria of Leucochloridium paradoxum Carus, recovered from Succinea putris L. in Norway, are described and figured. Adults recovered from experimental infection of Taeniopygia guttata (Vieillot) with L. paradoxum metacercariae are described, using results from scanning electron microscopy, and compared with earlier information. The family Leucochloridiidae Poche is revised. Four genera are recognized within the family (i.e. Leucochloridium Carus, 1835; Urogonimus Monticelli, 1888; Urotocus Looss, 1899; Michajlovia Pojmanska, 1973). The larval ecological and morphological characteristics are tabulated for the three genera with known larval stages. The status of the genus Neoleucochloridium Kagan, 1951, is changed, on the grounds of larval similarities with Leucochloridium Carus. This means that within the genus Leucochloridium Carus three subgenera are erected, based primarily on sporocyst characteristics. These are Leucochloridium, Neoleucochloridium and Papilloleucochloridium. The diagnostic larval and adult characters are tabulated. The known larval records of species in the genus Leucochloridium are discussed and revised within the framework of this new classification. ac]19790812  相似文献   

6.
The species of Ardeicola parasitic on the Ibis genus Threskiornis are reviewed-clayae Brelih, freemani sp.n., ibis Le Souef & Bullen, indicus Brelih, intermedia sp.n., nippon Hajela & Tandan-and a key for their identification is presented. Notes on the affinities of the species and a discussion on the distribution of Ardeicola on Threskiornis are included.  相似文献   

7.
The biological rate equation that describes the overall rate of substrate uptake by microbial films has been extended to microbial flocs with the aid of a shape parameter. The “solid”- and liquid-phase diffusion limitations are explored and found to depend largely on a dimensionles characteristic size k21Vp/Ap. Procedures are discussed by which k21Vp/Ap can be determined from experimental data on the conversion efficiency in a completely mixed fermentor and measurements carried out on flocs recovered from the fermentor are assessed. Floc size distributions are shown to affect the performance characteristics of a fermentor when some of the flocs are sufficiently large to exhibit a diffusional limitation, and it is concluded that a single mean floc size (k21Vp/Ap)* is sufficient to characterize a given distribution, at least when all the flocs are geometrically similar. The mean floc size closely corresponds to the “surface” mean floc size of the floc size distributions.  相似文献   

8.
Summary Seven suppressor mutations have been isolated in Aspergillus nidulans by coreversion of alleles in physiologically unrelated genes namely, alX, sB, alcA, putative structural genes for allantoinase, sulphate permease and alcohol dehydrogenase respectively. The suppressors are allele specific, gene unspecific. Those described map in four loci, suaA, B, C, D. suaA and suaB are on linkage group III, suaC and suaD on VII. suaB111, suaD103 and suaD108 are semi-dominant in their suppression of alX4 and sB43. suaA101, suaA105 and suaC109 are recessive and have a pleiotropic effect on morphology. SuaC109 is cold sensitive for growth as is sua115, an unmapped mutation on linkage group III which is similar in morphology to suaC109. The two mutations, SuaA101 and suaA105 have different spectra of suppression and morphologies. suaA105 weakly suppresses alX4 and sB43 whereas suaA101 strongly suppresses these and alcA125. suaD103 and suaD108 have the same spectrum of suppression. The properties of these suppressors are consistent with their being informational suppressors of the nonsense type.  相似文献   

9.
Molar Kerr contants mK have been determined for N-methylacetamide, N-ethyl-acatamide, N-methylpropionamide, N-acetylglycine-N′-methylamide, N-acetyl-L -ala-nine-N′-methylamide, and N-acetyl-L -leucine-N′-methylamide from electric birefringence measurements on dilute solutions in dioxane. The resultes are compared with configurational averatges 〈mK〉 calculated on the basis of conformational energies. Values ofmK calculated for various fixed confromations on the peptides vary over a wide range depending on the choice of conformation; hece, the configurational averages 〈mK〉 are sensitive to smalll changes in the conformational enerey. Kerr constants are calculated for random coiled oligoglycine and oligoalanine peptides as functions of chain length. The Kerr constant is an especially acute index of the average conformation.  相似文献   

10.
The morphology and development of the larval oral apparatus of Rana dalmatina, Bombina variegata, Bufo bufo, and Bufo viridis are described and compared using scanning electron microscopy. The species show different arrangements of the mouthparts. The small oral apparatus of R. dalmatina larvae has three labial tooth rows on the upper labium, while there are four tooth rows on the lower labium with a medial gap in row proximal to the mouth. The margins of the oral apparatus are defined by papillae that encircle the lower labium. B. variegata tadpoles have two upper labial tooth rows and three lower labial tooth rows that are uninterrupted, unlike the ones of R. dalmatina. The mouth is encircled by papillae that are larger than those of R. dalmatina. The oral discs of tadpoles of both B. bufo and B. viridis are similar. They are defined by two upper labial tooth rows (the second of which is interrupted by a medial gap) and by three lower tooth rows that differ in lengths in the two Bufo species. Both species develop papillae on the mouth angles and in two rows on the upper labium. Some morphological differences among the oral discs of R. dalmatina, B. variegata, B. bufo, and B. viridis tadpoles can be attributed to phylogenetic differences, but most can be related to their varying feeding habits and/or to their dietary specializations.  相似文献   

11.
Summary Two isoenzymes of alcohol dehydrogenase (adh I and adh II) from Saccharomyces cheresiensis have been differentiated by thermal treatment of the crude extracts. The effect of pH on the stability and the K m for ethanol are different for the two isoenzymes.The proportions in which they are present depend on the carbon source used by the yeast: adh I is the major component in cells grown on glucose, and adh II in those grown on ethanol. Cells grown on glucose plus ethanol show high levels of both isoenzymes, indicating that the synthesis of adh I is subjected to nutritional induction by glucose, and that of adh II by ethanol.The physiological roles of the two isoenzymes are discussed in relation with the nutritional characteristics of S. cheresiensis.  相似文献   

12.
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14.
Yasuo Suto 《Mycoscience》2009,50(5):357-368
Three species belonging to the genus Rhytisma causing tar spot were collected on leaves in evergreen trees of Ilex species from Japan. Rhytisma ilicis-latifoliae, the known species, is found on Ilex latifolia, and R. ilicis-integrae sp. nov. and R. ilicis-pedunculosae sp. nov. are found on I. integra and I. pedunculosa, respectively. Ascomata are formed on the abaxial part of the stromata in all the Rhytisma species studied, and spermogonia are formed on the amphigenous parts in R. ilicis-latifoliae and on the adaxial part in R. ilicis-integrae and R. ilicis-pedunculosae. Shape and size of asci, ascospores, and spermatia are distinctly different among the three species. The morphology of germination tubes from ascospores and appressoria is unique for each Rhytisma species. Yellowish spots arise on the newly developing leaves in mid-May, then abundant spermatia are produced in spermogonia in the three Rhytisma species. In the next year, ascospores are produced in ascomata from early April to late May in R. ilicis-integrae and from early April to early June in R. ilicis-latifoliae and R. ilicis-pedunculosae, and they are considered to be the inocula of disease infection.  相似文献   

15.
Using molecular karyotyping and genetic hybridization analysis, two new polymeric β-fructosidase genes, SUC9 and SUC10, were identified in the yeast Saccharomyces cerevisiae, which are located on chromosome XIV and on the chromosome XVI/XIII doublet, respectively. The genes are responsible for fermentation of sucrose and raffinose. The SUC gene genotypes of strains VKM Y-1831 and DBVPG 1340 are SUC2 SUC9 and suc2 0 SUC10, respectively. suc2 0 is a silent sequence. The scientific and applied significance of SUC genes is discussed.  相似文献   

16.
Parasitoid complexes of two species of the genus Phyllonorycter (Ph. apparella and Ph. populifoliella) reared from 2 plants (Populus tremula and P. nigra) were studied in Ul’yanovsk Province, Russia. Twenty species of parasitoids are new for Ph. apparella and 12 are new for Ph. populifoliella. Minotetrastichus frontalis and Pnigalio agraules are the dominant species for both parasitoid complexes. The highest relative abundance was observed for Ph. apparella on Populus tremula (75%) and for Ph. populifoliella on P. nigra (61%). The parasitoid complexes of Ph. apparella and Ph. populifoliella show high similarity (the Jaccard coefficient is 0.65).  相似文献   

17.
18.
In this paper, four fungi collected in Nansei Islands are reported. One is Strasseria garciniae, which must be transferred to the genus Phyllosticta. This fungus was collected in Okinawa Main Island and Iriomote Island. The other three fungi are newly added to the Japanese fungal flora. Phyllosticta ghaesembillae on Codiaeum variegatum and Cercospora asplenii on Asplenium antiquum were collected in Yoron Island. The last one, Coniella australiensis on Eucalyptus robusta was collected in Okinawa Main Island. Their morphology and symptoms on the host plant are described, with some mycological notes.  相似文献   

19.
The elder-instar larva of Altica deserticola is described for the first time, and the last-instar larva of A. engstroemi is re-described. The diagnostic characters are included. The former species develops on Glycyrrhiza, and the latter one, on Filipendula ulmaria. Some questions on the general morphology of the larvae of Altica are discussed.  相似文献   

20.
Modelling studies are presented which describe the effect of lek mating on the control of a wild population by sterile male release. The mixed leks are assumed to follow a Poisson-binomial distribution and the system includes three parts: territory defense, matings inside a lek and matings outside a lek. The effects of parameters on the hatchability are discussed. Among the parameters, sterile type effect (Ws), female choice (fs) and mating competitiveness (Cm) are the most important. The application to determining the effects of sterile male release and on the proportion of sterile males required for eradication are also discussed.  相似文献   

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