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1.
Ambrosius J.M. Dörr Marinella Rodolfi Massimiliano Scalici Antonia C. Elia Laura Garzoli Anna M. Picco 《Journal for Nature Conservation》2011,19(6):370-373
Non-indigenous crayfish species, carrier of the oomycete Aphanomyces astaci, are the most important threats to European crayfish species. However, other ectoparasite species have been reported to be the pathogen of aquatic organisms. As little is known about other potential pathogens carried by the red swamp crayfish Procambarus clarkii, a total of 86 individuals of this species was collected in Lake Trasimeno from June 2007 to 2008. Phoma glomerata, never recorded in Italy, colonised more than 65% of the captured crayfish. No significant differences in prevalence were recorded between sexes, among life stages and between soft- and hard-shelled crayfish. This Coelomycetes is the causal agent of many diseases in plants, animals and humans. These results may contribute to a better understanding of the implications of epibiontic microfungi on the invasive crayfish P. clarkii, for both ecological and sanitary purposes. 相似文献
2.
Throughout the world a number of problems have arisen following the introduction of new fish species; impacts of introductions are not limited to biological and ecological effects but may also have socioeconomic implications. Exotic and translocated fish species have become established in various parts of the inland waters of Turkey since the 1950s. The present paper reviewed ecological and economical effects of introduced freshwater fish of Turkey. 相似文献
3.
J. Jones 《Biodiversity and Conservation》1996,5(11):1433-1449
Diatoms are abundant and diverse in many Antarctic freshwaters, with a general trend of decreasing diversity moving southwards. They form an important component of many benthic algal communities in streams and standing waters but are generally less common in the phytoplankton. Diatoms are excellent ecological indicator species and, because their remains are preserved in many sedimentary environments, there appears to be a great potential for palaeoenvironmental reconstruction and the examination of past diversity. A lack of taxonomic precision and consistency, coupled with the insufficient collection from some geographical areas, makes the estimation of the number of Antarctic diatom species problematic. 相似文献
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5.
Xavier Turon Teruaki Nishikawa 《Journal of experimental marine biology and ecology》2007,342(1):185-188
The Mediterranean Sea is subject to an ever-increasing arrival of non-indigenous marine organisms. Microcosmus squamiger is a solitary ascidian that inhabits shallow rocky littoral habitats. It probably originated in Australia and it has shown great invasive potential in other parts of the world. In the Mediterranean, M. squamiger has only been reported at a few sites in Spain and Italy. However, the closely related species Microcosmus exasperatus has been reported in several areas of the western Mediterranean. As these species can be easily confused, we re-examined most of the material from previous studies and our personal collections. In addition, sampling was done at several sites along the western Mediterranean and Atlantic coasts. The results showed that the majority of the M. exasperatus reports correspond to M. squamiger, and that M. squamiger is common on the Atlantic shores. This suggests that M. squamiger has entered the Mediterranean through the Gibraltar Strait, while the restricted distribution in the eastern Mediterranean of M. exasperatus suggests that this species is probably a Lessepsian migrant. In the Mediterranean Sea, M. squamiger has the ability to occupy extensive areas of hard substrata and to outcompete native species. Further studies are necessary to assess what impacts this invasive species have on native communities. 相似文献
6.
The macrofauna of small isolated brackish waters on a barrier island in the Dutch Wadden Sea was sampled qualitatively. An attempt was made to correlate species composition and species richness to chlorinity characteristics and to data on the water regime of the localities studied.It is shown that the observed differences in the macrofauna cannot be explained by differences in chlorinity only. Present and former connections to other water bodies seem equally important. 相似文献
7.
Zoological gardens host large numbers of wild species and domestic forms, mostly not indigenous to the place where the zoological garden is located. Escapes (or releases) from zoological gardens are recognized as a pathway of introduction of alien species, leading in some cases to a naturalized population. Although previously reported worldwide, scientific accounts of escapes from zoos are rare and often anecdotal. In this note, we document, for the first time in Europe and, to our knowledge, in an area outside its native range, a case of introduction and establishment of a feral population of Llama (Lama glama), originating from a group of animals living in captivity at the Zoological Park of Cavriglia (Tuscany, central Italy). We reconstruct in detail the story of the population since 1974, also reporting preliminary data on abundance, distribution and diet. Finally, we critically evaluate the causes of this introduction, highlighting how unsafe the management of a zoological garden can be, and we discuss the implications for conservation and management perspectives. 相似文献
8.
To study how the population genetic structure in zooplankton respond to environmental conditions, using comparative limnology, the genetic diversity and genetic differentiation of the B. calyciflorus complex collected from four inland lakes in Wuhu City, China were investigated based on the 16S rRNA gene and nuDNA ITS sequences. The results displayed a high genetic diversity, and the nucleotide diversity of the 16S rRNA gene was higher than that of the ITS sequence. The phylogenetic analyses grouped the four populations into two cryptic species (Bc-JT and Bc-FL) with strong support. The two cryptic species were found in lakes with different trophic levels, demonstrating significant ecological specialization. The origins of clone TW12 were not consistent in the phylogenetic trees between two genetic markers, which might be attributed to the effects of male-mediated gene flow on the phylogenetic relationships of rotifers. The nucleotide diversity of the cryptic species Bc-JT was higher than that of Bc-FL, indicating that eutrophication might decrease the genetic diversity of cryptic species. The total phosphorus concentration in water bodies might be the most important factor affecting the genetic diversity of species. 相似文献
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L. FALCIANI L. BINI MALECI M. MAFUOTTILIPPI 《Botanical journal of the Linnean Society. Linnean Society of London》1995,119(3):245-256
The micromorphology and distribution of secreting and non-secreting trichomes in different parts of plants of the species belonging to Stachys, S. germanica group, of the Italian Flora, were studied. A peculiar capitate hair with multicellular head was found in all the species examined, with the exception of S. germanica ssp. germanica. This type of trichome is typically 4-celled in S. tymphaea. The distribution of trichomes on the calyces is particularly interesting and some peculiar features better characterize S. germanica ssp. germanica, S. germanica ssp. dasyanthes, S. cretica ssp. salviifolia, S. alpina and S. heraclea. 相似文献
11.
The Italian Protura were studied basing on 5103 specimens from 198 sampling areas, along with bibliographic data from 49 collecting sites. 17 out of the 20 Italian regions are covered. As a result, 40 species have been identified (belonging to 8 genera and 4 families), 6 of which are new records for the Italian fauna.A key to the Italian species is reported, followed by a series of distribution maps and brief remarks for some of them. A preliminary biogeographical overview allowed us to delineate the chorological categories of these species, 10 of which are actually known only in Italy. The comparison with the species richness known for some best studied Central and Eastern European Countries leads us to speculate that widening our research, Italian Protura check-list will be much implemented. 相似文献
12.
海南岛以南海域浮游植物群落特征研究 总被引:4,自引:0,他引:4
为掌握海南岛以南海域浮游植物群落特征, 1998–1999年对其进行了4个航次的现场调查。经显微镜检, 共鉴定出浮游植物290种(包括23个变种和5个变型)。在此基础上, 作者通过统计和聚类分析方法, 研究了这一区域浮游植物的物种组成、丰度变动和群落结构等特征。结果显示, 海南岛以南海域浮游植物物种丰富, 以硅藻门和甲藻门为主; 物种组成的时空差异显著。其优势种的暖水性、高盐性或广盐性特征明显。冷季以广温种小舟形藻(Navicula subminuscula)占优势, 随气温回升, 暖水性种类优势地位突出。不同季节浮游植物丰度差异小, 以硅藻门丰度占优势, 但与冷季相比, 暖季中甲藻门和蓝藻门丰度明显上升。4月和9月的高丰度中心位于西部海域北部湾湾口附近, 1月和12月则出现在中东部水域。聚类结果显示各浮游植物群落组分无明显的斑块分布特征。群落物种多样性表现为4月和9月高于1月和12月; 群落稳定性以12月份为最差; 中南部水域群落稳定性较差。总之, 海南岛以南海域浮游植物群落具独特的热带开阔海域生物区系特征。冷暖季群落特征有明显差异。海域水文条件对群落特征的影响复杂。 相似文献
13.
北部湾雷州近海春、夏季鱼类群落结构初探 总被引:2,自引:0,他引:2
根据2005年4月、7月和8月在北部湾雷州近海进行的渔业资源刺网和底拖网调查,对该海域春、夏季鱼类群落结构进行了初步研究.结果表明,银鲳(Stromateoides argenteus)是当地绝对的优势种,其它鱼类优势种随区域和季节有着较大的差异.分别计算了北部湾雷州近海春、夏季鱼类生物多样性指数的种类丰度指数(R)、多样性指数(H')、均匀度指数(J').聚类分析表明该水域鱼类群落结构存在一定程度的时空异质性,但空间异质性不如时间异质性明显.此外,不同群落中的鱼类呈现出不同的生态型特征.同时部分结果表明,在不同网具的调查下,有的结果会出现较大变化. 相似文献
14.
胶州湾近岸浅水区鱼类群落结构及多样性 总被引:5,自引:0,他引:5
根据2009年3月-2010年2月在胶州湾西北部近岸浅水区进行的鱼类逐月定置网调查数据,采用生态多样性指数和多元统计分析等方法研究了该海域的鱼类群落结构及多样性特征.结果表明:调查共鉴定出44种鱼类,其中海洋性27种,河口性鱼类17种.鱼类种类组成与底层水温和盐度有密切关系.胶州湾近岸浅水区鱼类群落Margalef种类丰富度指数(R)变化范围为0.33-3.50,Shannon-Wiener多样性指数(H’)为0.42-2.25,Pielou均匀度指数(J’)为0.23-0.93.聚类分析(CLUSTER)和多维标度排序(MDS)分析表明,不同鱼类种类组成的各月份样品可划分为3个组分:水温较低的冬季组G1(12月-翌年4月)、水温次高的春秋季组G2(5-6月、10-11月)和水温最高的夏季组G3(7-9月).其中G1的典型种主要为尖海龙(Syngnathus acus)、方氏云鳚(Enedrias fangi)和玉筋鱼(Ammodytes personatus)等冷温性常栖类群种类,G2的主要典型种为鳀鱼(Engraulis japonicus)和尖海龙,G3的主要典型种为鲐鱼(Scomber japonicus)、细条天竺鱼(Apogonichthys lineatus)和普氏缰虾虎鱼(Amoya pflaumi)等洄游性鱼类.单因子相似性分析(ANOSIM)表明,3个月份组间鱼类群落结构差异显著,不同月份组间两两差异均显著.生物-环境分析(BIOENV)表明,底层水温是影响胶州湾近岸浅水区鱼类群落结构时间变化的主要环境因子.在胶州湾内近岸浅水区发现40余种幼鱼,但占优势的主要为低值鱼类,表明胶州湾的产卵、肥育场功能有所下降,应加强胶州湾近岸水域生态环境和渔业资源的保护及修复. 相似文献
15.
东海中南部外海蟹类群落结构特征 总被引:3,自引:0,他引:3
2006年5月(春)、9月(夏)、11月(秋)和2007年2月(冬)对东海中南部外海(26°00′-28°30′ N,121°00′-126°00′ E)海域蟹类资源进行调查,分析了蟹类的种类组成、优势度、多样性和生物量等群落结构特征.结果表明:本次调查共鉴定蟹类49种,隶属于12科30属;春、秋季,调查海域蟹类种数呈北部高、南部低的特征,夏季各站位的蟹类种数分布较均匀,冬季该海域南北地区蟹类种数的差异较小,但调查海域外侧站位的种数较多;调查海域蟹类的优势种为13种,主要包括:双斑蟳、卷折馒头蟹、武士蟳、细点圆趾蟹、长手隆背蟹、光掌蟳和银光梭子蟹等;调查海域夏季的蟹类多样性指数较低,其他3个季节的差别不大;调查海域蟹类平均渔获资源量为5197.62 g·h-1,夏季(8830.79 g·h-1)﹥春季(4877.50 g·h-1)﹥秋季(4268.30 g·h-1)﹥冬季(2813.87 g·h-1).东海中南部外海蟹类可划分为3个生态群落,即广温广盐生态群落、高温广盐生态群落、高温高盐生态群落. 相似文献
16.
Marina I. Orlova Irena V. Telesh Nadezhda A. Berezina Alexander E. Antsulevich Alexey A. Maximov Larissa F. Litvinchuk 《Helgoland Marine Research》2006,60(2):98-105
An increase of xenodiversity in plankton and benthos in the eastern Gulf of Finland was observed from 1998 to 2004. Nonindigenous species account for 4.8% of all species found and up to 96% of total biomass. Invasive benthic omnivores, the alien amphipods Gmelinoides fasciatus and Pontogammarus robustoides and the predaceous fish Perccottus glenii with their versatile diets strongly affect the community structure. Invasive sessile seston-feeders that directly (through grazing and water clearance) and indirectly (through recycling of nutrients) interact with other ecosystem components, are mainly represented by the zebra mussel Dreissena polymorpha, which affect the structure of benthic and planktonic communities as well as benthic-pelagic coupling. The invasive predatory cladocerans Cercopagis pengoi and Evadne anonyx and larvae of D. polymorpha are only temporary components in the zooplankton, which is limiting their overall effect. Alien benthic bioturbators, the polychaetes Marenzelleria neglecta and the oligochaete Tubificoides pseudogaster account for a high proportion of total abundance and biomass but their effects on native species need further research. 相似文献
17.
Prangnell DI Fotedar R 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2006,145(4):449-457
Two trials were conducted to determine the effect of sudden decrease in salinity of raw and potassium-fortified inland saline water on western king prawn Penaeus latisulcatus osmoregulation, ionoregulation and condition. Prawns were subjected to salinity decrease over 1 h from 32 to 25 ppt in the first trial and from 27 to 20 ppt in the second trial in three water types: inland saline water with potassium fortified to 100% and 80% of the marine water concentration (IS100, IS80), and raw inland saline water (ISW). In the first trial condition and ingestion rate were monitored over 19 days following salinity change. In the second trial condition, haemolymph osmo- and iono-regulation were recorded over 48 h following salinity change. In the first trial, 100% mortality was observed in ISW by day 13, with final survival 94% in IS80 and 100% in IS100. Tail muscle moisture content increased significantly (P < 0.05) over time in both trials and in all water types, suggesting loss of energy reserves. In the second trial, serum osmolality, sodium concentration and osmoregulatory capacity decreased following salinity change, stabilising by 24 h in IS100 and IS80 but continuing to decrease till 48 h in ISW, suggesting partial breakdown of osmoregulatory function in the potassium-deficient medium. Prawns were stronger regulators of divalent than monovalent cations. These trials demonstrate that potassium-deficient inland saline water requires fortification with potassium to allow prawn survival and efficient osmoregulation. 相似文献
18.
In this contribution the results of a zoogeographical analysis, carried out on the 123 endemic leaf beetle species (Coleoptera: Chrysomelidae) occurring in Italy and its immediately adjacent regions, are reported. To assess the level of faunistic similarity among the different geographic regions studied, a cluster analysis was performed, based on the endemic component. This was done by calculating the Baroni Urbani & Buser’s similarity index (BUB). Finally, a parsimony analysis of endemicity (PAE) was used to identify the most important areas of endemism in Italy. 相似文献
19.
At present, there are 43 self-sustaining fish species in Norwegian fresh waters, 11 (26%) of which are non-native, representing four families (Salmonidae, Cyprinidae, Centrarchidae and Ictaluridae). Human-mediated fish introductions probably began in the 15th century with common carp Cyprinus carpio, but most have occurred between the late 1800s and late 1900s. The number of known established populations varies from one (goldfish Carassius auratus ) to nearly 250 (tench Tinca tinca ). Dispersal risk is also highest with tench, which is being spread by anglers for its appeal as a trophy fish. Intentional introductions to improve amenity angling have been part of fisheries management programmes ( e.g. brook trout Salvelinus fontinalis ), so this appears to be an increasingly common introduction vector despite the prohibition under legislation of introducing any species of non-native fishes. Some introduced species, such as brook trout, have declined in abundance and number of populations as the quality of acidified waters has been restored, being replaced by native brown trout Salmo trutta . Further range expansion by some species ( e.g. common carp, goldfish and pumpkinseed Lepomis gibbosus ) is probably restricted by current climatic conditions. 相似文献
20.
A. Costán‐Longares L. Mocé‐Llivina A. Avellón J. Jofre F. Lucena 《Journal of applied microbiology》2008,105(6):1945-1955
Aims: Update information regarding occurrence and levels of culturable enteroviruses in several types of surface polluted waters in north‐eastern Spain and determine the proportion of the different species and serotypes. Methods and Results: The best procedures on hand in our laboratory for concentrating and quantifying culturable enteroviruses from different water sample types were used. Sequencing was used for typing the virus isolates. Geometric means of enteroviruses densities expressed in plaque forming units per litre were 968 in raw sewage, 12·51 in secondary effluents, 0·017 in tertiary effluents, 0·4 in river water and 0·36 in seawater. Enterovirus densities in wastewater revealed certain seasonality with a maximum at the end of spring – beginning of the summer. Coxsackievirus B, and amid them serotype CB4, were the most abundant species and serotypes detected. Conclusions: Densities of enteroviruses in different north‐eastern Spain surface waters are similar to those present in industrialized countries with temperate climate. No wild polioviruses were detected. Distribution of species showed a clear prevalence of coxsackieviruses. Significance and Impact of the Study: Information regarding enteroviruses in this geographical area provides valuable information to estimate the risk of enteroviruses transmission through water and for complementing clinical epidemiological data. 相似文献