532 resultados para Phenacoccus Parvus
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小型桡足类在生态系统中的重要作用近年来得到了广泛的关注,在近岸生态系统中,小型桡足类起着相当重要的作用。但关于小型桡足类种群动力学的研究在国内还处于起步阶段,因此我们选取了国内沿岸海域常见优势种小拟哲水蚤、双刺纺锤水蚤、太平洋纺锤水蚤及强额拟哲水蚤等四种小型桡足类为研究对象,探讨其种群动力学相关方面的变动机制。本文在2005年10月-2006年9月选取胶州湾为主要的研究海域,进行了一周年的小型桡足类的采样和培养实验研究。在胶州湾,小拟哲水蚤(Paracalanus parvus)全年出现,其种群数量变动呈现双峰型,在夏季(6月和8月)达数量高值,在冬季(1月)有一个小的高峰。种群数量在4月达全年最低值,在7月份数量也有一个明显的数量降低。从空间分布上来讲,该水蚤在冬季主要以CV期桡足幼体存在于湾南和湾外区域,湾北数量很少;从春末开始,各期幼体开始在各海区广泛分布。小拟哲水蚤在胶州湾几乎全年产卵(2月份除外),但较高的产卵率主要集中在春末到秋初,最大产卵率出现在5月,达27.9 eggs female-1d-1。总体来讲,在胶州湾小拟哲水蚤的产卵率与温度、叶绿素及体长均呈显著正相关,但与盐度呈负相关关系。从不同的区域来看,胶州湾湾北区域小拟哲水蚤产卵率较高,最高值出现在湾北6月份,产卵率达到了60.8 eggs female-1d-1。大于10 eggs female-1d-1的产卵率在湾北持续了6个月(4-9月),在湾口持续了5个月(4-8月),而在湾外只持续了3个月(5-7月)。小拟哲水蚤生物量在6月份达到最高值(6.15 mg C m-3),在4月达到全年最低值(0.028 mg C m-3)。次级生产的变动从4月到9月与生物量的变动趋势完全相似,但冬季生物量的高峰并没有伴随次级生产的高峰值,分析其原因是由于冬季低的生长率所致。小拟哲水蚤在整个胶州湾平均的年次级生产为158.41 mg C.m-3yr -1。强额拟哲水蚤(Paracalanus crassirostris)在胶州湾只在夏末到秋季出现,最大数量出现在8月份。从强额拟哲水蚤的分布区域来看,从湾内到湾外有递减趋势。在2006年9月份,只有湾北有部分种群,其他区域几乎没有该种出现。该种最大产卵率出现在8月,达11.2 eggs female-1d-1。强额拟哲水蚤生物量的变动与次级生产的变动趋势相似,最大值也都出现在8月份。该水蚤在胶州湾平均年次级生产仅为2.12 mg C m-3yr-1。双刺纺锤水蚤(Acartia bifilosa)在胶州湾是全年出现,其种群数量在5-6月份突发性增加达全年最高值(>8000 ind. m-3),之后又急剧下降。从该种的区域分布来看,5-6月份数量的高峰主要出现在湾北区域,7月份虽然各区域数量均下降,但大部分种群集中在湾外区域。双刺纺锤水蚤在胶州湾几乎全年产卵(1-2月除外),产卵率的最高值出现在4月,达16.5 eggs female-1d-1。4月份雌体高的产卵率为5月份种群数量的大量增加提供了补充。双刺纺锤水蚤生物量与次级生产的变动趋势一致,在5-6月份达到高值,在秋冬季次级生产较低。双刺纺锤水蚤在整个胶州湾平均的年次级生产为114.61 mg C m-3yr-1。太平洋纺锤水蚤(Acartia pacifica)在胶州湾季节性出现,在冬春季节消失,从夏季开始出现。该种在5月零星出现,种群数量在6月份开始增多,到7月份达到最高值2356 ind. m-3,之后在8月数量锐减至196 ind. m-3。从区域分布来看,该水蚤在胶州湾只出现在湾北和湾南区域,湾外区域几乎没有,而且呈现湾北到湾南递减的趋势。6月份数量大部分出现在湾北区域,到7月份才有一部份在湾南出现。太平洋纺锤水蚤在其出现季节均产卵,最大产卵率出现在6月份,达37.17 eggs female-1 d-1,部分补充了7月份太平洋纺锤水蚤种群数量的大量增加。太平洋纺锤水蚤生物量与次级生产的变动趋势相似,在7月份达到了最高值,在11月达到最低值。太平洋纺锤水蚤在胶州湾平均的年次级生产为45.63 mg C m-3yr-1。胶州湾四种小型桡足类总的年次级生产为~320 mg C m-3 yr-1。
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Copepod communities in onshore and offshore waters show a gradient from primarily near shore to primarily oceanic species. Understanding the transition between these communities is fundamental to determining the range of coastal influence. Copepod communities in the northern South China Sea (nSCS) were studied based on samples collected by vertically towing a net in 10 February-6 March (winter) and 26 August-6 September (summer) of 2004. Calanoida species richness, total copepod abundance, Shannon-Weaver diversity index, and onshore-offshore occurrence of dominant species showed obvious change from onshore to offshore waters. Although the offshore stations had lower abundance than the shelf stations, they had more species and larger diversity index. Abundance of some species (groups) with dominance index > 5% (Calanus sinicus, Euchaeta spp., Temora spp., Paracalanus parvus, and Subeucalanus subtenuis) declined from onshore to offshore waters. Warm water species (Pleuromamma abdominalis, P. gracilis, and P. robusta) occurred in offshore waters in both cruises. Station (q-type) cluster analysis in winter and summer separated copepod community into onshore and offshore communities at similar to 40% level of similarity. The two communities were divided at the position of similar to 100-m isobath. In summer, C. sinicus occurred in the upwelling area east of Hainan Island, indicating the presence of an oversummering stock of this species.
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During spring (April/May 1999) and autumn (September/October 1998) cruises in the Bohai Sea, China, copepods were the dominant components of mesozooplankton, the most abundant species being Calanus sinicus, Centropages mcmurrichi, Paracalanus parvus, Acartia bifilosa and Oithona similis. Pigment ingestion rates by three size classes of copepods (200-500, 500-1000 and > 1000 mum) were measured. In the south of the investigation area, gut pigment content (GPC), individual pigment-specific ingestion rates and grazing impacts on phytoplankton were lower in spring than in autumn. In the central area, GPC and individual pigment-specific ingestion rates were higher in spring than in autumn. The grazing impact on phytoplankton by the copepod assemblages was lower in spring than in autumn, however, because of the relatively smaller biomass in spring. In the western area where the Bohai Sea joins the Yellow Sea, GPC, individual pigment-specific ingestion rates and grazing impacts on phytoplankton were higher in spring than in autumn. Among the three size groups, the small-sized animals (200-500 mum) contributed more than 50% (range 38-98%) of the total copepod grazing during both cruises. The grazing impact on phytoplankton by copepods was equivalent to 11.9% (range 3.0-37.1%) of the chlorophyll-a standing stock and 53.3% (range 21.4-91.4%) of the primary production during the spring cruise. Grazing impact was equivalent to 6.3% (range 2.0-11.6%) of the chlorophyll-a standing stock and >100% (range 25.7-141.6%) of the primary production during the autumn cruise. The copepod community apparently consumed only a modest proportion of the standing stock of phytoplankton during spring and autumn blooms. They did, however, sometimes graze a significant proportion of daily primary production and hence were presumably able to limit the rate of further accumulation of phytoplankton, or even to prevent it. (C) 2003 Elsevier Ltd. All rights reserved.
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The Bohai Sea was the site of the Chinese national GLOBEC programme. During the June 1997 cruises of R/V Science No.1, observations and experiments on zooplankton feeding were conducted. At five 48 h time-series stations the following observations and measurements on zooplankton were carried out: (1) diurnal vertical migration, by collecting samples at different layers every 3 h with a closing net; (2) diurnal feeding rhythms, by gut pigment analysis; and (3) ingestion rate, by both gut pigment analysis and the dilution method. A classification by body size was used to deal with the diversity of species and developmental stages of zooplankton assemblages. Samples were separated into three size groups: small (200-500 mu m), medium (500-1000 mu m) and large (> 1000 mu m). The results showed that the copepods (Calanus sinicus, Paracalanus parvus, Acartia bifilosa and Centropages mcmurrichi) performed clear diurnal vertical migrations. However, their behaviour was different at different stations. The variation in gut pigment content over the 24 h cycle showed strong diurnal feeding rhythms, particularly for the large size group. Gut pigment contents reached their daily maximum during the time from dusk to midnight (18:00-24:00). The peak value was about 10 times the minimum observed in the daytime. The in situ daily grazing rate, based on gut pigment contents and evacuation experiments, was 4.00-12.65 ng chla ind(-1) day(-1) for the small size group, 5.99-66.58 ng chla ind(-1) day(-1) for the medium size group and 31.31-237.13 ng chla ind(-1) day(-1) for the large size group. The copepods consumed only a small part (2.90-13.52%) of the phytoplankton biomass hut about 77% of the daily production. The grazing mortality rate of phytoplankton by microzooplankton (<200 mu m) measured by the dilution method ranged from 0.43 to 0.69 day(-1) The calculated daily consumption of phytoplankton biomass was 35-50%, and 85-319% of the potential production.
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Four time-series of copepod species biomass in the north of Spain were contrasted to demonstrate spatial autocorrelation of local communities and their responses to short-term local and regional variability in oceanographic conditions. The series represented coastal and oceanic environments along a marked gradient of influence of seasonal upwelling from Galicia to the Mar Cantábrico (S Bay of Biscay), and each one included at least 10 years of continuous data collected at monthly frequency. Community composition (i.e. species number and diversity) was very consistent through the region, but local variations in the presence of new species and the relative proportions of common species allowed for the characterisation of the response to the environment at each site. Small-sized species were more frequent near the coast. A few species, however, captured the main patterns of variability in all series. Calanus helgolandicus and Acartia (mainly Acartia clausi) were generally the main contributors to total biomass, while other species as Paracalanus parvus and Clausocalanus spp. were important only at some locations. Most copepod indices were positively correlated with upwelling, either considering the whole community (biomass, species richness and diversity) or individual species, but only in the coastal series analysed since 1991. Copepods in the nearby ocean, however, showed negative correlations with upwelling in the period 1960–1986. The effects of upwelling may have been modulated by local factors, as showed by the increases in biomass, number of species and diversity in associations with increases in sea surface temperature in Galicia, while in the Mar Cantábrico only the warming-tolerant species increased and those typical of upwelling decreased. Density stratification of the water column was associated with decreases in total copepod biomass in Galicia, while it favoured the increase in species richness in the Mar Cantábrico. Nearly all significant responses of copepods to environmental variability were delayed by up to 5 months, showing the importance of considering time-lags in the analysis of temporal responses of zooplankton.
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Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015
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Contient : Recueil de « receptes » ou remèdes contre différentes maladies, parmi lesquelles (p. 42) : « Dix rigles par quoy l'on peult entendre pourquoy les femmes ont chascun mois leurs fleurs, selon Me Benard de Gourdon. Cy commence le secret des dames, que fait entendre legerement le gouvernement des fleurs des dames... » ; « Le formulaire des aides des appostumes et pustules, ordonné à Paris par Me Guidon de Cailhac, cirurgien et maistre en medecine à Montpellier, l'an mil IIIcXL. Pour ce que selon la doctrine de Ga[lien]... — ... Explicit parvus Guido »
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Four strains of a novel yeast species were isolated from laboratory nests of the leaf-cutting ant Atta sexdens in Brazil. Three strains were found in older sponges and one was in a waste deposit in the ant nests. Sequencing of the D1/D2 region of the large-subunit rRNA gene showed that the novel species, named Sympodiomyces attinorum sp. nov., is phylogenetically related to Sympodiomyces parvus. Unlike Sympodiomyces parvus, Sympodiomyces attinorum can ferment glucose, assimilate methyl alpha-D-glucoside, salicin and citrate, and grow at 37 degreesC, thus enabling these two species to be distinguished. Differentiation from other related species is possible on the basis of other growth characteristics. The type strain of Sympodiomyces attinorum is UNESP-S156(T) (=CBS 9734(T)=NRRL Y-27639(T)).
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Comparative cytogenetic analyses were carried out in six species of Brachycephalidae from southeastern Brazil. Barycholos ternetzi, Eleutherodactylus binotatus, Eleutherodactylus guentheri, Eleutherodactylus juipoca, Eleutherodactylus parvus and Eleutherodactylus sp. have 2n = 22 karyotypes with a marked variation in the morphology of chromosome pairs 8, 10 and 11, which are of telocentric or metacentric types, resulting in FN = 38, 40 and 44. Eleutherodactylus have a single chromosome pair bearing Ag-NOR, i.e. pair 1 in E. binotatus, pair 6 in E. guentheri and E. parvus, and pair 11 in E. juipoca and Eleutherodactylus sp. In contrast, B. ternetzi showed Ag-positive sites in the chromosome pairs 1, 4, 5, 9 and 11, and only one to three labelings per metdphase in each individual. Nevertheless, the main chromosome pair with Ag-NOR in the species seems to be the 11th, like in E. juipoca and Eleutherodactylus sp. The NOR site was confirmed by fluorescence in situ hybridization (FISH) technique in E. binotatus and in B. ternetzi, bearing 1p1p and 9p11p11p Ag-NOR pattern, respectively. All the species exhibited predominantly centromeric C-banding pattern, but interstitial bands have also been observed in some cases. In E. binotatus, there is an indication of geographical difference in the distribution of the interstitial C-bands. The fluorochromes GC-specific chromomycin A(3) (CMA(3)) and AT-specific 4',6-diamidino-2-phenylindole (DAPI), with distamycin A (DA) counterstaining, provided the molecular content of some repetitive regions in the karyotypes of the species. One male of E. binotatus presented an extensive heteromorphism, involving at least five different pairs, probably as a consequence of multiple reciprocal translocations. Such rearrangements might be responsible for the multivalent chain seen in the meiosis of this specimen, as well as in another male, although not exhibiting chromosome heteromorphism. The remaining males and those belonging to the other species have always shown 11 bivalents in diplotene and metaphase I cells. In all male specimens, metaphases II presented 11 chromosomes. Despite the observed discrepancies, the five species of Eleutherodactylus have a great uniformity in the 2n = 22 karyotypes, suggesting an assemblage of species from southeastern and southern Brazil, in contrast to northern and northeastern assemblage which is characterized by higher diploid numbers. Undoubtedly, B. ternetzi could be included in that proposed assemblage, due to its karyotypic similarity with the Eleutherodactylus species, as evidenced in the present study. This fact strongly supports the close relationships of both genera, previously inferred on the basis of several characters shared by their species. (C) 2006 Elsevier Ltd. All rights reserved.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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A caracterização da composição de Copepoda planctônicos, na costa do Amapá foi estudada, a partir de amostras coletadas através do programa REVIZEE, durante a Operação Norte IV, em 2001, realizada pelo navio Oceanográfico “Antares”, pertencente à Marinha do Brasil (H-40). A área estudada está inserida na ZEE Norte brasileiro no trecho entre o Cabo Orange e o Delta do rio Parnaíba, enquadrando-se nas seguintes coordenadas geográficas, LAT. 02º 25,92’N e LONG. 049º11,98’W (est. 102); LAT. 03º36,14’N e LONG. 048º24,71’W (est. 107); LAT. 05º32,39’N e LONG. 050º13,11’W (est.130); LAT. 04º23,64’N e LONG. 051º02,58’W (est.134). As coletas foram realizadas através de arrastos verticais com rede de zooplâncton, com malha de 200 μm, dotadas de fluxômetro. Após as coletas, as amostras foram fixadas com formol neutro a 4 %. Também foram coletados os fatores hidrológicos, onde a temperatura da água variou de 23, 72 ºC a 28,87 ºC na plataforma continental, enquanto na região oceânica variou de 12,69 ºC a 28,87 ºC. A salinidade, na plataforma continental, variou 24,00 PSU a 36,42 PSU, e na região oceânica a variação foi de 33,98 PSU a 36,62 PSU. A costa do Amapá foi considerado um ambiente estável, devido as poucas variações de salinidade e temperatura. Foram identificadas 84 espécies de Copepoda, das quais, destacaram-se como as mais freqüentes, Clausocalanus furcatus, Oithona setigera, Paracalanus parvus, Macrosetella gracilis, Oncaea media, Corycaeus speciosus, Farranula gracilis, Subeucalanus pileatus e Paracalanus sp. As altas densidades e dominância ocorreram para as espécies, Nannocalanus minor, Corycaeus (Corycaeus) speciosus, Clausocalanus furcalocalanus pavo, Paracalanus parvus, Parvocalanus crassirostris, Oithona setigera, Macrosetella gracilis, Farranula gracilis, Subcalanus pileatus, Euterpina acutifrons e Oncaea media, consideradas como indicadoras de oligotrofia na área estudada. Dentre estas, a espécie Subeucalanus pileatus foi a que mais se destacou, a qual ocorreu na maioria das estações. A diversidade foi considerada alta na maioria das estações, exceto na estação 127 (considerada baixa), por estar sendo influenciada pela pluma amazônica. Enquanto, a densidade apresentou resultados menores que 100 org.m-³ indicando a região oceânica como um ambiente oligotrófico, e apesar disso, a comunidade de Copepoda encontra-se em grande diversidade na área.
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Insects of the suborder Heteroptera are known for their odor, for being pests, or for being disease carriers. To gain better insight into the cytogenetic characteristics of heteropterans, 18 species of terrestrial Heteroptera belonging to eight families were studied. The presence of heteropycnotic corpuscles during prophase I, terminal or interstitial chiasmas, telomeric associations between chromosomes, ring disposals of autosomes during metaphase, and late migrations of the sex chromosomes during anaphase were analyzed. These features showed identical patterns to other species of Heteroptera previously described in the literature. Another studied characteristic was chromosome complements. The male chromosome complements observed were 2n = 12 chromosomes [10A + XY, Galgupha sidae (Amyot & Serville) (Corimelaenidae) and Pachycoris torridus (Scopoli) (Scutelleridae)]; 2n = 13 [10A + 2m + X0, Harmostes serratus (Fabricius), Harmostes apicatus (Stål), Jadera haematoloma (Herrich-Schaeffer), Jadera sanguinolenta (Fabricius), Jadera sp. (Rhopalidae)], and Neomegalotomus parvus (Westwood) (Alydidae); 2n = 13 [12A + X0, Stenocoris furcifera (Westwood) (Alydidae); 2n = 14 [12A + XY, Dictyla monotropidia (Stål) (Tingidae)]; 2n = 19 [18A + X0, Acanonicus hahni (Stål) (Coreidae)]; 2n = 21 [18A + 2m + X0, Acanthocephala sp. (Dallas) (Coreidae)]; 2n = 27 [24A + 2m + X0, Anisoscelis foliacea marginella (Dallas) (Coreidae)]; 2n = 18 [16A + XY, Oncopeltus fasciatus (Dallas) (Lygaeidae)]; 2n = 17 [14A + X1X2Y, Oxycarenus hyalinipennis (Costa) (Lygaeidae)]; 2n = 16 [12A + 2m + XY, Pachybrachius bilobatus (Say) (Lygaeidae)]; 2n = 26 [24A + XY, Atopozelus opsinus (Elkins) (Reduviidae)]; and 2n = 27 [24A + X1X2Y, Doldina carinulata (Stål) (Reduviidae)]. The diversity of the cytogenetic characteristics of Heteroptera was reflected in the 18 studied species. Thus, this study extends the knowledge of these characteristics, such as the variations related to chromosome complements, sex chromosome systems, and meiotic behavior.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Diatom analyses with an annual resolution were carried out on varves of the hypertrophic Baldeggersee (Central Swiss Plateau) for the timespan ad 1885 to 1993. They reveal seven major changes in the dominant planktonic diatoms. As a result of progressive nutrient enrichment, Baldeggersee changed in the 1910s from a Cyclotella to a Tabellaria fenestrata dominated assemblage, and eventually in the 1950s to a Stephanodiscus parvus dominated diatom assemblage. The timing and direction of diatom-assemblage changes in the varved sediment compare well with sedimentological and limnological observations. Partitioning of the variance in the diatom data revealed that TP is a stronger explanatory variable than temperature for these changes. A diatom-inferred total phosphorus (TP) reconstruction indicates three major steps in eutrophication, occurring at 1909, the mid-1950s and the mid-1970s. Comparison with TP measurements in the water column demonstrates that the diatom-TP inference model used is able to hindcast past TP concentrations reliably. The major steps in eutrophication led to decreases in diatom diversity and also resulted in a progressive increase of calcite grain-size. The lake restoration programme established since 1982 shows no direct impact on the composition of the diatom assemblages. However, the decrease in phosphorus loads since the mid-1970s is reflected in the diatom assemblages and in decreasing diatom-inferred TP concentrations.