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1.
The taxonomic status and validity of Scymnodon macracanthus (Regan, 1906) and Scymnodon plunketi (Waite, 1910) are revised in light of new material from the Southern Pacific and Indian Oceans. Despite being historically accepted as distinct taxa, recent studies suggested the possibility that these species could represent a single taxon. Morphometrics, meristics and morphology of dermal denticles show that S. plunketi is indeed a junior synonym of S. macracanthus. Previous distinctive characters proved to be the result of intraspecific variation. S. macracanthus is therefore redescribed including an updated comparative diagnosis for the genus Scymnodon in the family Somniosidae.  相似文献   

2.
Abstract. The freshwater ostracod Tonnacypris glacialis (Sars, 1890) is reported from the European Pleistocene for the first time. The historical allocation of the species is discussed, and the species composition and characteristics of Tonnacypris Diebel & Pietrzeniuk (1975) and its phylozoogeography are considered. The significance of T. glacialis is reviewed, particularly from the viewpoint of the possible implications of parthenogenesis (and occasional-male production) for the Quaternary history of the genus, and for the use of the species in palaeoenvironmental reconstruction. It is suggested that the Pleistocene fossil occurrence of T. glacialis in modern temperature latitudes is a robust indicator of mean summer temperatures of 6°C.  相似文献   

3.
A new species of Haplometroides (Digenea, Plagiorchiidae) is described from a specimen of Phalotris nasutus (Gomes, 1915) (Serpentes, Colubridae). The host snake was obtained in the municipality of Corumbd, Mato Grosso do Sul State, Brazil. Trematodes were recovered from esophagus, stomach, and small intestine of the host. The main characteristic of the new species is the vitellaria, which is intercecal, cecal, and extracecal in the preacetabular region. A key for identification of the species in Haplometroides is proposed.  相似文献   

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Disolution of Co(bzt)2(NCS)2 (bzt = benzo 1,3- thiazole) in dimethyl formamide (dmf) produces Co(bzt)2(NCS)2(dmf)2. The stoichionmetry of the complex has been established by a combination of chemical (C, H, N) and thermal analysis. The comlex has an octahedral structure with pairs of ligands in trans configuration as well as a CoN4O2 coordination sphere with CoN distances of 2.185(2) Å (bzt); 2.082(2) Å (NCS) and CoN(dmf) of 2.118(2) Å. The infrared and electronic absorption spectra are consistent with this arrangement.  相似文献   

6.
In order to investigate the relationship existing between the electronic structures of collagen and its biochemical functions in vivo, the semiempirical CNDO/2 SCF MO calculations were carried out on several model polymers of collagen, (Gly-Pro)n, (Gly-Hyp)n, (Ala-Pro)n, (Ala-Hyp)n, (Gly-Pro-Gly)n, (Gly-Hyp-Gly)n, (Gly-Pro-Pro)n and (Gly-Pro-Hyp)n. Geometries of the skeleton of these polymers were assumed to be the same as those of poly(l-proline) I (cis) and II (trans) and the calculations were performed only on infinite polymers in a single chain. The results show that the cis form is always more stable than the trans form for all the polymers treated. This energy difference between the cis and trans forms depends, for example, on the kind of amino acid residue, Gly or Ala, but this could not be seen in the Pro or Hyp residue. The flexibility or mobility of the collagen structure was explained using the energy difference between the cis and trans forms of the polymers, i.e. the cis-trans conversion of the collagen was discussed in connection with the energy difference. The reason why the collagen has the constitution of (Gly-Pro-Hyp)n is briefly discussed.  相似文献   

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The species composition and taxonomic structure of lamellicorn beetles of Northeast China are considered. A total of 317 species from 86 genera, 42 tribes, 18 subfamilies, and 6 families are known to occur in the fauna of Manchuria. Seven species are recorded from China for the first time: Trox scaber (Linnaeus, 1767), Glyptotrox ineptus (Balthasar, 1931), Aegialia (Psammoporus) kamtschatica Motschulsky, 1860, Aphodius (Acrossus) superatratus Nomura et Nakane, 1951, Aphodius (Chilothorax) grafi Reitter, 1901, Maladera spissigrada (Brenske, 1897), and Valgus hemipterus hemipterus (Linnaeus, 1758); in addition, 18 species are recorded as new to the fauna of Manchuria. Among 177, 219, 208 and 226 species recorded from the Manchurian part of Inner Mongolia, Heilongjiang, Jilin, and Liaoning, 20, 29, 14 and 19 species are new to the region, respectively. The ecological and zoogeographical features of Scarabaeoidea in Manchuria are analyzed. Data on the trophic structure, phenology, and distribution of all the taxa are presented.  相似文献   

11.
The parakeet (or budgerigar) has been transported to many regions of the world. Two species of feather mites, Protolichus lunula (Robin) (Pterolichoidea: Pterolichidae) and Dubininia melopsittaci n. sp. (Analgoidea: Xolalgidae), are specific to this host; from distribution records, these ectoparasites probably have been distributed worldwide with their hosts.  相似文献   

12.
Ardeirhynchus spiralis (Rudolphi, 1809) n. g., n. comb. (syns Echinorhynchus spiralis, Prosthorhynchus spiralis and Plagiorhynchus spiralis), a parasite of herons (Ciconiiformes: Ardeidae), is redescribed on the basis of the holotype from Ixobrychus minutus and specimens from Ardeola ralloides (new host record) in Bulgaria. A. spiralis is a member of the family Polymorphidae and not of the Plagiorhynchidae in which it was previously classified. Ardeirhynchus n. g. is distinguished from the most morphologically similar genus, Arhythmorhynchus Lühe, 1911, by the position of the male genital system, which occupies the posterior 1/8-1/6 part of the trunk, the distribution of hypodermal nuclei in groups in the anterior part and in lateral rows along the length of the posterior part of the trunk, a considerably shorter neck, minute trunk spines and a terminal genital pore.  相似文献   

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This note reports on the presence of a well established population of the isopod Synidotea laevidorsalis (Miers) in the Gironde estuary (southwestern France). This species is new for the European fauna. S. laevidorsalis is a nonendemic cool-temperate to subtropical, shallow-water species which was probably introduced into the study area from Asia. In the salinity range of 1 to 10 g 1-1 of the Gironde the species constitutes an important component of the brackish-water hyperbenthic community. The population was already present in 1975 when it was misidentified as the native species Idotea emarginata (Fabricius).  相似文献   

15.
SUMMARY

The two African leeches Placobdella stuhlmanni (Blanchard, 1897) and Placobdella garoui (Harding, 1932) are redescribed and figured because of the confusion that exists in the literature with regard to the specific identities of the two taxa. During a survey of the freshwater leeches of the Republic of South Africa and South West Africa, material was obtained which made possible a thorough study of the two species. Not only did this clear up existing discrepancies but the research also added much new information concerning the two leeches. Certain aspects of their biology are considered for the first time.  相似文献   

16.
Potamolithus Pilsbry &; Rush, 1896 is a species-rich genus, endemic to South America, with many of its species considered Vulnerable due to a restricted distribution; half of them are called into question, since they are known only from their shells. The purpose of this article is to describe the anatomy of P. paranensis (Pilsbry, 1911 Pilsbry, H.A. (1911) Non-marine Mollusca of Patagonia. In: Scott, W.B. (Ed.), Reports of the Princeton University Expeditions to Patagonia, 1896–1899, Vol 3, Zoology, Part V. The University, USA, Princeton, NJ, pp. 513633. [Google Scholar]) and P. simplex (Pilsbry, 1911 Pilsbry, H.A. (1911) Non-marine Mollusca of Patagonia. In: Scott, W.B. (Ed.), Reports of the Princeton University Expeditions to Patagonia, 1896–1899, Vol 3, Zoology, Part V. The University, USA, Princeton, NJ, pp. 513633. [Google Scholar]) from the Argentinean Misiones province, and to evaluate the value of anatomical features in this genus. These two species differ in penis morphology and pigmentation, ctenidium length, and relative position of the opening of the pallial oviduct, seminal receptacle and bursa copulatrix. Consequently, it appears that anatomical data could help solve taxonomic conflicts that are currently unresolved by shell morphology alone.  相似文献   

17.
《Journal of Asia》2021,24(3):912-917
Efficacy of Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae) was determined by studying its biological and behavioural attributes on the aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae). Total developmental duration of the parasitoid was longer in younger instars compared to that in older instars of aphid. Host age negatively affected the oviposition period and fecundity of the ovipositing parasitoid. Survival of the immatures was higher in older than the younger instars of the aphid. Sex ratio for the parasitoid was female-biased. Longevity of female parasitoid was higher while parasitizing aphid nymphs of younger age groups (1–2 days old) compared to that of older age groups (4–5 days old). Parasitoid showed a higher preference towards second instar of M. persicae both in choice and no-choice tests. Results on mutual interference revealed that per capita searching efficiency decreased from 0.91 to 0.07 as parasitoid densities increased from 1 to 8. Logistic regression exhibited a type II functional response for D. rapae. The estimated values of search-efficiency (a) and handling time (Th) were 0.038 h−1 and 1.59 h, respectively. The maximum parasitization rate was 15.08. This investigation suggests that D. rapae could be an effective candidate for augmentative biological control of M. persicae which infests several plant species of economic importance.  相似文献   

18.
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.  相似文献   

19.
The objective of this work was to verify the sensitivity of Amblyomma cajennense and Dermacentor nitens larvae to the solvents ethanol, methanol, acetone, xylol and dimethyl sulfoxide (DMSO) and the surfactant Tween 80. The first four solvents were tested at analytical purity while the DMSO and surfactant Tween 80 were tested at a concentration of 1%. The substances tested at analytical purity that caused high mortality were also tested at concentrations of 50%, 25% and 1%. The larval packet test was used, with 10 repetitions for each treatment. A control group was also formed with the same number of repetitions, in which the larvae were only exposed to distilled water. In the first experiment, only xylol was highly toxic at the concentrations tested, causing mortality above 90% for larvae of both species. In the second experiment, xylol at 1% and at 25% showed low toxicity to the A. cajennense and D. nitens larvae, respectively, since the percentage mortality was statistically similar to that of the control group (p>0.05).  相似文献   

20.
The digenean originally designated Lepidapedon (Lepidapedon) ostorhinchi is redescribed from its type-host, Oplegnathus woodwardi [= Ostorhinchus conwaii], from the waters off Western Australia. The discovery of a uroproct indicates that the generic designation is wrong and the worm should be Paralepidapedon ostorhinchi (Korotaeva, 1974) n. comb. It is distinct from its nearest relative, P. hoplognathi (Yamaguti, 1938), in having: a prominent post-oral ring; a distinct oesophagus; short anterior diverticula on the caeca; a long external seminal vesicle, ensheathed in a membrane bound gland-cell mass; and less anteriorly extensive vitellarium.  相似文献   

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