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1.
Japanese eel is already magnetosensitive at the glass eel phase. However, currently, there is no evidence that they can use geomagnetic cues for orientation. We examined orientation behaviour in a radially symmetrical test arena in which the horizontal component of the geomagnetic field could be manipulated. Groups of glass eels released at the centre of the arena showed a mean orientation angle significantly biased to the south of 198° in the ambient geomagnetic field, but showed random orientation in the geomagnetic field when its horizontal component was cancelled in a solenoid. Results showed that they use geomagnetic cues for orientation. 相似文献
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Akihiro Okamura Yoshiaki Yamada Kazuki Yokouchi Noriyuki Horie Naomi Mikawa Tomoko Utoh Satoru Tanaka Katsumi Tsukamoto 《Environmental Biology of Fishes》2007,80(1):77-89
To establish a simple and reliable index for determining silvering stages of the Japanese eel, Anguilla japonica, we observed the colorations of various body parts and biological characteristics of the eels collected in a coastal area
of Japan (Mikawa Bay). The four silvering stages are characterized by the colorations of pectoral fins and ventral skin as
follows: (1) Y1, yellow eel without a metallic hue at the base of pectoral fins, (2) Y2, late yellow eel with a metallic hue
at the base of the pectoral fins but without melanization at the tip of pectoral fins, (3) S1, silver eel with complete melanization
at the tip of pectoral fins but without full pigmented belly in black or dark brown, and (4) S2, late silver eel with black
or dark brown belly. The body size, eye diameter and sexual maturity of each stage increased in the order of Y1, Y2, S1 and
S2 stages, whereas the digestive tract degenerated in the same order, suggesting a sequential development of these ontogenetic
stages identified in the study. The Y1, Y2 and S1 stages could be also distinguished by canonical discriminant function analysis
using three internal (gonad-somatic index, GSI; hepato-somatic index, HIS; and gut index) and two morphometric (condition
factor and eye index) parameters, supporting the significance of these stages. This method of staging for the silvering process
of the Japanese eel appeared to be applicable to all specimens of this species, since this index used only simple external
characteristics that would be easy to observe during field surveys. 相似文献
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Overwintering sites have recently been a focus of research into adaptive insect behavior in areas where winter is severe; however, little is known about the overwintering sites of most insects, including common ground or carrion beetles. Here, we reveal the overwintering site of Japanese carrion beetles Eusilpha japonica (Motschulsky) (Coleoptera: Silphidae). These beetles occupy various locations between spring and autumn; however, they are not observed in most of these places in winter. To investigate where they overwinter, a thorough scan was made of 109 sites. Overwintering beetles were found at 21 of 73 sites near to trees, and no beetles were observed at 36 sites that were not close to trees. To evaluate the influence of trees on the abundance of overwintering beetles, we established a quadrat consisting of 518 subquadrats in a suitable habitat with varying distances to the nearest trees. We caught 118 overwintering beetles in the quadrat. More beetles existed in subquadrats closer to trees, and analyses that considered spatial autocorrelation revealed a negative correlation between beetle frequency and distance to the nearest tree. 相似文献
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Hai-Nan Su Bin-Bin Xie Xiu-Lan Chen Jin-Xia Wang Xi-Ying Zhang Bai-Cheng Zhou Yu-Zhong Zhang 《Journal of applied phycology》2010,22(1):65-70
Allophycocyanin (APC) is a minor component of phycobiliproteins in cyanobacteria and red algae. This paper describes a simple and inexpensive extracting method for isolating APC from Spirulina (Arthrospira) platensis with high efficiency. The crude phycobiliprotein extract was pretreated by ammonium sulfate fractionation. Then, by adding hydroxylapatite into crude phycobiliprotein extract dissolved in 20 mM phosphate buffer (pH 7.0), APC was selectively adsorbed by hydroxylapatite but C-phycocyanin (C-PC) was not. The hydroxylapatite was collected and APC was extracted from the crude phycobiliprotein extract. Then, the enriched APC was washed off from the hydroxylapatite using 100 mM phosphate buffer (pH 7.0). In this simple extracting method it was easy to remove C-PC and isolate APC in large amounts. The absorbance ratio A 650/A 280 of extracted APC reached 2.0. The recovery yield was 70%, representing 4.61 mg · g−1 wet weight. The extracted APC could be further purified by a simple anion-exchange chromatography with a pH gradient from 5.6 to 4.0. The absorbance ratio A 650/A 280 of the purified APC reached 5.0, and the overall recovery yield was 43%, representing 2.83 mg · g−1 wet weight. Its purity was confirmed by native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate-PAGE. 相似文献
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Luciano Elias Oliveira Kátia G. Facure Ariovaldo A. Giaretta 《Environmental Biology of Fishes》2012,93(1):89-94
We present data on the habitat, density, and spatial distribution of Rivulus giarettai, and discuss some biotic and abiotic variables related to its abundance in Free Flowing Waters (FFW) and Dam Reservoirs (DR) in palm grove (Mauritia flexuosa) marshes (Veredas) in Uberlandia, Minas Gerais, southeastern Brazil. The mean density (individuals/plot) of R. giarettai was about 13 times higher in FFW than in DR. In FFW, the density of R. giarettai was highest at intermediate amounts of substrate (plant mass) and it was positively rank-correlated with the depth, and the number of arthropods. Individuals occurred in an aggregated distribution. The aggregated pattern could be related to a concentration of individuals in microhabitats neither too much exposed nor completely saturated by plants. R. giarettai was relatively abundant and tolerant to slight man-made habitat modifications. Damming appeared to be especially problematic by negatively affecting its density. 相似文献
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Norishige Yotsukura Kouhei Nagai Hajime Kimura Kouichi Morimoto 《Journal of applied phycology》2010,22(4):443-451
The seasonal variation in protein expression in the sporophyte of Saccharina japonica (Areschoug) Lane, Mays, Druehl and Saunders was investigated. High-quality proteins that are available for protein profiling were extracted by the ethanol/phenol extraction method, and 564 protein spots in total were detected. Proteins were identified through database search by combining Mascot and MS BLAST for 100 spots, and significant difference of expression level between the samples collected in winter and in summer was observed in the case of 95 spots. Within 67 spots upregulated in the samples collected in summer, vanadium-dependent bromoperoxidase (vBPO) were identified for 21spots. It is thought that the elevation of expression level of vBPO in summer depend on the activation of the functions: (1) elimination of active oxygen species and protection of the algal body from oxygen injury, (2) prevention of the growth inhibition due to the adherence of attached organisms, in the season. 相似文献
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Marcin Sielezniew Izabela Dziekańska Anna M. Stankiewicz-Fiedurek 《Journal of Insect Conservation》2010,14(2):141-149
Phengaris (=Maculinea) arion is an endangered social parasite of Myrmica ants, and for a very long time was considered as specific to Myrmica sabuleti. Previous studies carried out in Poland suggested some discrepancies within this assumption, and therefore a much more intensive survey was undertaken. The host ant use of P. arion was studied at five sites in different types of biotopes in Poland, i.e. xerothermal grasslands where Thymus pulegioides was used as a larval food plant by the butterfly, and more or less sandy biotopes with Thymus serpyllum. Altogether nine Myrmica species were recorded, and considerable variation in species composition and density of nests was recorded. At four localities M. sabuleti proved to be the most common ant. A total of 529 Myrmica nests were examined, and only 20 of them contained larvae and pupae of P. arion. Host ants belonged to five different species, i.e. M. sabuleti, Myrmica scabrinodis, Myrmica schencki, Myrmica lobicornis and Myrmica hellenica. Only at one site (NE Poland) was a significant heterogeneity in parasitation rates among Myrmica species detected. M. lobicornis was the most often infested ant there, which may suggest local specialisation of the butterfly. Overall low parasitism rates may explain the vulnerability of P. arion in Central Europe but further studies are also necessary. 相似文献
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I. Rosario G. Soro S. Déniz O. Ferrer F. Acosta D. Padilla B. Acosta 《Mycopathologia》2010,169(4):315-319
Columba livia is an important reservoir and carrier of Cryptococcus neoformans, Cryptococcus uniguttulatus, Cryptococcus laurentii and Cryptococcus albidus. Upper digestive tract of this species is also known as a habitat for Cryptococcus neoformans. Given the increasing clinical interest of this microorganism, 331 swabs from crop and 174 dropping samples from pigeon lofts in Grand Canary Island have been studied. The obtained results show an extensive presence samples 81 positive (24.47%) of Cryptococcus spp. in analysed crops: 32 (9.66%) for C. neoformans, 24 (7.2%) for C. uniguttulatus, 23 (6.9%) for C. albidus and 2 (0.6%) for C. laurentii. In the same way, Cryptococcus spp was also isolated in 82 (47.13%), dropping samples: C. neoformans in 59 (33.9%), C. uniguttulatus, in 9 (5.17%), C. laurentii in 8 (4.59%) and C. albidus in 6 (3.44%) of the investigated samples, respectively. The cryptococcosis produced by species of cryptococci other than C. neoformans has become more important during the last decade, supporting the study on the role of pigeon in the epidemiology of this disease. 相似文献
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Jiu-Cun Wang Syeling Lai Xinjian Guo Xuefeng Zhang Benoit de Crombrugghe Sonali Sonnylal Frank C Arnett Xiaodong Zhou 《Arthritis research & therapy》2010,12(2):R60
Introduction
SPARC is a matricellular protein, which, along with other extracellular matrix components including collagens, is commonly over-expressed in fibrotic diseases. The purpose of this study was to examine whether inhibition of SPARC can regulate collagen expression in vitro and in vivo, and subsequently attenuate fibrotic stimulation by bleomycin in mouse skin and lungs. 相似文献17.
N. Yu. Markelova 《Microbiology》2010,79(6):777-779
Interaction of Bdellovibrio bacteriovorus 100NCJB with bacteria Campylobacter jejuni (strains 1, 2, 3, 4, and 5) and Helicobacter pylori, strain TX30a, was confirmed. The results indicate that lytic activity of bdellovibrios both in liquid media and cells attached to a surface was observed. The potential use of the antimicrobial activity of predatory bacteria for environmental bioprotection and public health is discussed. 相似文献
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Following a re-examination of the material treated under Barleria brevispina (Fiori) Hedrén in the recent Flora of Somalia account of the Acanthaceae, it is concluded that two distinct species are involved and Barleria compacta Malombe & I. Darbysh. is described here from north-eastern Somalia. Its affinities and conservation status are discussed. 相似文献
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Katsura Ito 《Experimental & applied acarology》2011,53(1):51-56
In several adult-diapausing insects and mites, long duration of diapause decreases egg production after diapause termination. However, such nonlethal effects are much less studied than overwintering survival. In this study, lethal and nonlethal effects of different periods of diapause were investigated in an adult-diapausing spider mite, Tetranychus kanzawai Kishida (Acari: Tetranychidae), through field experiments. Diapausing females produced in the laboratory were kept in their natural habitat from October or November to the next April, and survival rate and postdiapause fecundity were compared between the months. The survival rate was lower, but not significantly, in the October treatment. Postdiapause fecundity was also not significantly different between the months. These results suggest that the effects of diapause on survival and reproduction are quite small after October, when diapausing mites are increasing in their natural habitat. 相似文献
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