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《Ibis》1897,39(4):564-574
A mongst the Waders, a class of birds I have had unusual opportunities of watching for many years along the shores of Kingsbridge Estuary, South Devon, the Bar-tailed Godwits have always been a great attraction. The striking change of plumage from winter to summer, their erratic appearance at the times of migration, and the desire to raise this group above the level of that hen-pecked one of Phalaropes, to which they have been likened in their habits of courtship and nidification, have induced me to follow the Godwit in his coming in and going out ever since I could tell one bird from another. 相似文献
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《Biochemical Systematics and Ecology》2005,33(7):675-679
The inflorescences of Eleocharis elegans and Eleocharis sellowiana were investigated by dynamic headspace/GC–MS for the presence of volatiles. No floral volatile was detected in the inconspicuous inflorescences of E. sellowiana but various floral volatiles were produced by the showy inflorescences of E. elegans. The results are discussed in their ecological and evolutionary context. 相似文献
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Pseudodelphis oligocotti n. gen., n. sp. (Dracunculoidea; Guyanemidae) is described from the tidepool sculpin, Oligocottus maculosus (Scorpaeniformes; Cottidae), from various localities in coastal British Columbia. The species is placed in Guyanemidae because of its reduced buccal capsule, divided esophagus, functional vulva, and single ovary. It is distinguished from Guyanema, the only other genus in the family, by the absence of caudal alae and the arrangement of caudal papillae in the male. Females of the new genus are distinguished from those of Guyanema by the presence of a blind uterine diverticulum, without associated oviduct and ovary, extending anteriorly from the junction of the posterior uterus and vagina, and a more posteriorly positioned vulva. Fish were sampled every 2 wk throughout 1988. Worms were overdispersed in the host population. Prevalence and mean intensity of infection were highest from February to March. 相似文献
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Maïté Niepceron Florence Portet-Koltalo Chloé Merlin Anne Motelay-Massei Sylvie Barray & Josselin Bodilis 《FEMS microbiology ecology》2010,71(1):137-147
Like other highly urbanized and industrialized estuaries, the Seine estuary (France) has, for decades, received high inputs of polycyclic aromatic hydrocarbons (PAHs). In order to estimate the bioremediation potentials and to identify the bacterial species involved in hydrocarbon degradation, we used microcosms containing seawater from the Seine estuary supplemented with either naphthalene, phenanthrene, fluorene or pyrene. In the microcosms enriched with naphthalene or phenanthrene, hydrocarbon biodegradation was significant within 9 weeks (43% or 46%, respectively), as shown by analyses in GC-MS. In similar microcosms incubated also with naphthalene or phenanthrene, analysis of the 16S rRNA gene sequences (DNA and cDNA) with denaturing gradient gel electrophoresis and clone libraries indicated that the PAH-degrading communities were dominated by Cycloclasticus spp., confirming their universal key role in degradation of low-molecular-weight PAHs in marine environments. However, in contrast to previous studies, we found that Pseudomonas spp. also degraded naphthalene and phenanthrene in seawater; this occurred only after 21 days, as was confirmed by real-time PCR. Although this genus has been abundantly described in the literature as a good PAH-degrading bacterial group in soil or in sediment, to our knowledge, this is the first evidence of a significant fitness in PAH degradation in seawater. 相似文献
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BOSA E. OKOLI F.L.S. OMOTOYE OLORODE 《Botanical journal of the Linnean Society. Linnean Society of London》1983,87(3):263-271
Cytogenetic studies in the Andropogon gayanus—A. tectorum complex (Granimae). Studies on the morphology, karyotype and meiotic behaviour of collections of Andropogon gayanus [2 n = 40), A. tectorum (2 n = 20,30) and their hybrids, obtained by both open pollination and controlled crosses, have been made. The chromosome number of 2 n = 30 for A. tectorum is new. Karyotypic analyses of the species and the preponderance of trivalents at diakinesis in the triploid and aneuploid hybrids show that considerable homology exists between the genomes of the two species. The evolutionary relationship between the two species and the probable origin of tetraploid A. gayanus are discussed. 相似文献
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由于Rudolf
G(o)rz在1935年《静生生物调查所汇报》(植物学)第6卷第1期"中国柳属增志"一文中对2新种、2新变种和1新变型植物名称发表时引证了2号或2号以上的标本,但没指定主模式.根据《国际植物命名法规》规则8.1、9.4、9.9、9.10和辅则9A.1、9A.2、9A.3、9A.4的精神,对这些名称作出后选模式指定. 相似文献
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Manihot alterniflora and M. elongata spp. nov. (Euphorbiaceae) and the rediscovery of M. quinquefolia in Caatinga (semiarid) vegetation in Brazil
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Márcio Lacerda Lopes Martins Paulo Cezar Lemos de Carvalho Carlos Alberto da Silva Ledo André Márcio Amorim 《Nordic Journal of Botany》2018,36(3)
We describe and illustrate two species of Manihot that occur in Caatinga (semiarid) vegetation in Brazil and redescribe and lectotypify M. quinquefolia Pohl, which was only known from a single collection made by J. E. B. Pohl in 1827. Manihot elongata P.Carvalho & M.Martins is widely distributed and Manihot alterniflora P.Carvalho & M.Martins is endangered because of its small populations and restricted area of occurrence. We establish M. quinquefolia as the only species of Manihot in the Caatinga with compound leaves. An identification key is provided for the 13 species of Manihot present in the Caatinga. 相似文献
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The ruff, Gymnocephalus cernua, is a European freshwater fish that feeds by sucking up small invertebrates from the bottom of ponds and slow flowing rivers. The feeding movements have been studied by simultaneous electromyography of seventeen muscles of the head and cinematographic techniques. A theoretical model of movements imposes the functional demands of suction upon an abstraction of the form of a teleost head. Three phases in the feeding act, a preparatory phase, a suction phase and a transport phase, could be correlated with the observed movements and EMGs. Differences between the predicted and the actual movement are discussed. Two different types of feeding occur. The direction, magnitude and duration of the suction forces during feeding are modified, according to the position of the prey. A mechanism preventing early mandibular depression allows sudden and strong suction. Retardation of the suspensorial abduction during the overall expansion of the buccal cavity is ascribed to kinetic interrelations with the hyoid arch. Protrusion of the upper jaws also permits an earlier closure of the mouth and directs the food-containing waterflow posteriorly. When the fish is feeding on sinking prey, protrusion occurs later in the sequence of movements than when it is feeding from the bottom. As the protruded jaws produce a downwardly pointed mouth this retardation aims the suction force. 相似文献
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Maria Luisa Tunes Buschini 《Journal of Zoological Systematics and Evolutionary Research》2007,45(3):206-213
Hymenopterans have become a model for the study of factors that govern sex allocation. In 1983, Seger proposed a model to study Sphecidae wasps with a strong prediction that sex ratio for univoltine wasps should be 1 : 1 (female : male), and for partially bivoltine species it should be male-biased. The present study investigates if Trypoxylon lactitarse (Saussure, 1867) is a univoltine or a bivoltine species and if Seger's model prediction fits the pattern of sex ratio found in this species. The study was carried out at Parque Municipal das Araucárias, in the municipality of Guarapuava, state of Paraná, southern Brazil, from December 2001 to December 2004. Nests of T. lactitarse were obtained using trap-nests drilled longitudinally to a depth to 80 mm with 7.0, 10.0 and 13.0 mm opening diameter. They were placed in a very heterogeneous site filled with araucaria forests, swamps and grasslands. Trypoxylon lactitarse showed two alternative life histories: either they pupated immediately and emerged as adults later in the same season (direct development), or they entered diapause, overwintering and pupating the following spring (delayed development). Its annual sex ratios were not significantly different from 1 : 1, and both sex ratio of overwintering and sex ratio of direct-developing wasps were also not significantly different from 1 : 1, in all years of this study. By examining these results, it was possible to conclude that although T. lactitarse is a multivoltine species, with four generations per year and two alternative life histories, its sex ratio did not support Seger's model. 相似文献
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A male infant is described with unusual facial appearance, clubfeet, and moderate hydrocephalus internus without obvious deficiency in mental and physical development. Cytogenetic studies revealed a karyotype of 45,XY,--C,--D,+t(C;D). A chromosome 11 and a 13 are involved in the formation of the translocation chromosome. The long arm of chromosome 13 is linearly attached to the end of the long arm of chromosome 11 (tandem translocation). Chromosome material of the distal part of the long arm of chromosome 11, as well as the short arm plus the centromere of chromosome 13 seem to have been lost. 相似文献
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Nil Rahola Jér?me Depaquit Boris Kevin Makanga Christophe Paupy 《Memórias do Instituto Oswaldo Cruz》2013,108(7):845-849
During a research project aimed at the study of the Culicinae fauna of Gabon and
carried out in the National Park of La Lopé, we captured an unknown sandfly male
specimen (genus Phlebotomus) by CDC miniature light trap
belonging to a new species for Science. Furthermore, the originality of his
genitalia does not allow us to include this species in one of the existing
subgenus, thus in this paper we propose the creation of a new subgenus, as
Phlebotomus (Legeromyia) multihamatus sp. nov., subg. nov.
described from the National Park of La Lopé, through one male captured with CDC
miniature light trap. A new species and a new subgenus of sandfly is
characterised by a short style with three spines, a paramere wearing a basal
hook as well as a basal pouch and the absence of basal lobe on the coxite. The
originality of the genitalia of the male gives way to discussion about potential
primary homologies between P. multihamatus sp. nov. and
Phlebotomus (Abonnencius) fortunatarum, Phlebotomus
(Anaphlebotomus) stantoni and Phlebotomus (Euphlebotomus)
argentipes, which should be verified for future studies. The
discovery of this new species in Gabon must encourage the study of sandflies in
this country. 相似文献