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Global diversity of inland water cnidarians is low, containing <40 species belonging to phylogenetically distinct groups representing
independent invasion events: the common and cosmopolitan hydras (12–15 species); the sporadically occurring freshwater medusae
(6–16 sp.); the Cordylophorinae (2 sp.); the parasitic Polypodium (1 sp.); the medusae occurring in saline lakes (4 sp.). Freshwater cnidarians inhabit nearly all types of freshwater on all
continents (except Antarctica), but only a few species have cosmopolitan distributions. Due to uncertainty in species knowledge,
fine scale regions of endemicity are not yet clear.
Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment 相似文献
3.
Reviews in Fish Biology and Fisheries - Freshwater eels are of tropical marine origin and have spread worldwide. Of the 19 recognised species or subspecies, all 6 temperate species are listed... 相似文献
4.
Oribatid mites are primarily terrestrial. Only about 90 species (less than 1% of all known oribatid species) from 10 genera
are truly aquatic, with reproduction and all stages of their life cycle living in freshwater. Adaptation to aquatic conditions
evolved independently in different taxa. However, many terrestrial species can also be found in aquatic habitats, either as
chance stragglers from the surrounding habitats, or from periodic or unpredictable floodings, where they can survive for long
periods. In spite of their low species richness aquatic oribatids can be very abundant in different freshwater habitats as
in lentic (pools, lakes, water-filled microhabitats) or flowing waters (springs, rivers, streams), mainly on submerged plants.
The heavily sclerotized exoskeletons of several species enables subfossil or fossil preservation in lakes or bog sediments.
Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment 相似文献
5.
Fengzhi He Vanessa Bremerich Christiane Zarfl Jonas Geldmann Simone D. Langhans Jonathan N. W. David William Darwall Klement Tockner Sonja C. Jähnig 《Diversity & distributions》2018,24(10):1395-1404
Aim
Freshwater megafauna remain underrepresented in research and conservation, despite a disproportionately high risk of extinction due to multiple human threats. Therefore, our aims are threefold; (i) identify global patterns of freshwater megafauna richness and endemism, (ii) assess the conservation status of freshwater megafauna and (iii) demonstrate spatial and temporal patterns of human pressure throughout their distribution ranges.Location
Global.Methods
We identified 207 extant freshwater megafauna species, based on a 30 kg weight threshold, and mapped their distributions using HydroBASINS subcatchments (level 8). Information on conservation status and population trends for each species was extracted from the IUCN Red List website. We investigated human impacts on freshwater megafauna in space and time by examining spatial congruence between their distributions and human pressures, described by the Incident Biodiversity Threat Index and Temporal Human Pressure Index.Results
Freshwater megafauna occur in 76% of the world’s main river basins (level 3 HydroBASINS), with species richness peaking in the Amazon, Congo, Orinoco, Mekong and Ganges‐Brahmaputra basins. Freshwater megafauna are more threatened than their smaller counterparts within the specific taxonomic groups (i.e., fishes, mammals, reptiles and amphibians). Out of the 93 freshwater megafauna species with known population trends, 71% are in decline. Meanwhile, IUCN Red List assessments reported insufficient or outdated data for 43% of all freshwater megafauna species. Since the early 1990s, human pressure has increased throughout 63% of their distribution ranges, with particularly intense impacts occurring in the Mekong and Ganges‐Brahmaputra basins.Main conclusions
Freshwater megafauna species are threatened globally, with intense and increasing human pressures occurring in many of their biodiversity hotspots. We call for research and conservation actions for freshwater megafauna, as they are highly sensitive to present and future pressures including a massive boom in hydropower dam construction in their biodiversity hotspots.6.
The freshwater crayfishes are distributed across all but the Indian and Antarctic continents with centers of diversity in
the southeastern Appalachian Mountains in the Northern Hemisphere and in south–east Australia in the Southern Hemisphere.
There are currently over 640 described species of freshwater crayfishes with an average of 5–10 species still being described
each year. Freshwater crayfishes can serve as keystone species in aquatic habitats, but a few species are also significantly
invasive and can cause impressive damage to the fragile freshwater habitat. Crayfishes inhabit caves, burrows, streams, lakes
and strong burrowers can even be found in terrestrial habitats where they have burrowed to the water table or where rainfall
is sufficiently abundant to provide the needed moisture. The freshwater crayfishes, like the habitats in which they are encountered,
are generally endangered to some degree and conservation efforts would do well to focus on them as key elements of the freshwater
ecosystem.
Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment 相似文献
7.
Darren C. J. Yeo Peter K. L. Ng Neil Cumberlidge Célio Magalhães Savel R. Daniels Martha R. Campos 《Hydrobiologia》2008,595(1):275-286
An assessment of the global freshwater crab diversity is presented. A total of 1,476 species in 14 families are currently
known from all zoogeographical regions (except Antarctica), including 1,306 species in eight exclusively freshwater families
(Pseudothelphusidae, Trichodactylidae, Potamonautidae, Deckeniidae, Platythelphusidae, Potamidae, Gecarcinucidae and Parathelphusidae).
Estimates of true freshwater crab diversity including likely numbers of undescribed taxa suggest that the field remains largely
in a “discovery” phase. Main ideas on the origins, diversification, and phylogeny of true freshwater crabs are briefly discussed.
The economic importance of freshwater crabs is also highlighted.
Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment 相似文献
8.
Georgina Bond-Buckup Carlos G. Jara Marcos Pérez-Losada Ludwig Buckup Keith A. Crandall 《Hydrobiologia》2008,595(1):267-273
The freshwater anomuran crabs of the family Aeglidae are all restricted to southern South America occurring in Chile, Brazil,
Bolivia, Uruguay, Paraguay, and Argentina. The family consists of a single genus, Aegla, containing 63 currently described species. There are another 5–10 known yet undescribed species to complement this diversity.
The aeglids occur in freshwater lakes, streams, rivers, and in caves with freshwater. The origin of the family appears to
be from marine ancestors from the Pacific invading streams in Chile about 75 mya radiating both in Chile and again on the
eastern side of the Andes, particularly in Brazil. Of the 63 species, 23 or 36.5% are considered under threat and are in need
of conservation action.
Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment 相似文献
9.
Most ribborn worms (phylum Nemertea) are marine and only 22 of the currently named around 1,200 species are known from freshwater
habitats (mainly lakes/ponds). They are all free-living benthic forms found in all continents except Antarctica. The vast
majority of species have been recorded from the Palearctic region, but this may reflect sampling efforts rather than biogeography.
Guest editors: E.V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment 相似文献
10.
A list of the snake species inhabiting freshwaters is provided. It includes 153 species, which represents about 5% of all
known snakes. These freshwater snakes belong to 44 genera distributed among the families Acrochordidae, Boidae, Colubridae,
Elapidae, Homalopsidae and Viperidae. The highest diversities in freshwater snakes are found in the Oriental (64 species)
and Neotropical (39 species) Regions. Conservation actions are needed for several overcollected species with a limited distribution.
Guest editors: E. V. Balian, C. Lévêque, H. Segers, & K. Martens
Freshwater Animal Diversity Assessment 相似文献
11.
Pollination-induced flower senescence: a review 总被引:11,自引:0,他引:11
A. D. Stead 《Plant Growth Regulation》1992,11(1):13-20
Ethylene has long been implicated in the control of the senescence of many cut flower species, but the control of senescence in relation to wild species has received much less attention. The longevity of individual flowers varies greatly from species to species; in some each flower is open for just a few hours, whilst in others the flower may persist for several weeks, or even months. The functional life of the flower may be terminated by petal wilting, abscission or a colour change of all, or part, of the perianth. In some species pollination appears to reduce floral longevity whilst in others, particularly those species having short-lived flowers, the pattern of flower development and senescence appears unaffected by pollination.Examples of the various pollination-induced strategies shown by plants are presented and the role of ethylene and other potential mediators of senescence in these processes discussed. 相似文献
12.
Leopoldo M. Rueda 《Hydrobiologia》2008,595(1):477-487
Mosquitoes that inhabit freshwater habitats play an important role in the ecological food chain, and many of them are vicious
biters and transmitters of human and animal diseases. Relevant information about mosquitoes from various regions of the world
are noted, including their morphology, taxonomy, habitats, species diversity, distribution, endemicity, phylogeny, and medical
importance.
Guest editors: E. V. Balian, C. Lévêque, H. Segers and K. Martens
Freshwater Animal Diversity Assessment 相似文献
13.
副原吸鳅属鱼类一新种(鲤形目:平鳍鳅科) 总被引:1,自引:0,他引:1
本文记述采自广西巴马的平鳍鳅科鱼类一新种,即巴马副原吸鳅Paraprotomyzonbamaensissp.nov。对新种的形态特征进行了描述,并与近似种进行了比较。 相似文献
14.
辽宁淡水鱼类寄生艾美虫属二新种(真球虫目:艾美科) 总被引:1,自引:0,他引:1
本文记述艾美虫属Eimeria Schneider,1875二新种:寄生于鲢、鳙肾脏的柳壕艾美虫,新种Eimeria liuhaoensis sp.nov.。寄生于草鱼肾脏的草鱼艾美虫,新种Eimeria ctenopharyngodoni sp.nov.。 相似文献
15.
Global diversity of aquatic macrophytes in freshwater 总被引:2,自引:0,他引:2
Aquatic macrophytes are aquatic photosynthetic organisms, large enough to see with the naked eye, that actively grow permanently
or periodically submerged below, floating on, or growing up through the water surface. Aquatic macrophytes are represented
in seven plant divisions: Cyanobacteria, Chlorophyta, Rhodophyta, Xanthophyta, Bryophyta, Pteridophyta and Spermatophyta.
Species composition and distribution of aquatic macrophytes in the more primitive divisions are less well known than for the
vascular macrophytes (Pteridophyta and Spermatophyta), which are represented by 33 orders and 88 families with about 2,614
species in c. 412 genera. These c. 2,614 aquatic species of Pteridophyta and Spermatophyta evolved from land plants and represent
only a small fraction (∼1%) of the total number of vascular plants. Our analysis of the numbers and distribution of vascular
macrophytes showed that whilst many species have broad ranges, species diversity is highest in the Neotropics, intermediate
in the Oriental, Nearctic and Afrotropics, lower in the Palearctic and Australasia, lower again in the Pacific Oceanic Islands,
and lowest in the Antarctic region. About 39% of the c. 412 genera containing aquatic vascular macrophytes are endemic to
a single biogeographic region, with 61–64% of all aquatic vascular plant species found in the Afrotropics and Neotropics being
endemic to those regions. Aquatic macrophytes play an important role in the structure and function of aquatic ecosystems and
certain macrophyte species (e.g., rice) are cultivated for human consumption, yet several of the worst invasive weeds in the
world are aquatic plants. Many of the threats to fresh waters (e.g., climate change, eutrophication) will result in reduced
macrophyte diversity and will, in turn, threaten the faunal diversity of aquatic ecosystems and favour the establishment of
exotic species, at the expense of native species.
Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment 相似文献
16.
Role of fungi in freshwater ecosystems 总被引:7,自引:0,他引:7
Michelle K.M. Wong Teik-Khiang Goh I. John Hodgkiss Kevin D. Hyde V. Mala Ranghoo Clement K.M. Tsui Wai-Hong Ho Wilson S.W. Wong Tsz-Kit Yuen 《Biodiversity and Conservation》1998,7(9):1187-1206
There are more than 600 species of freshwater fungi with a greater number known from temperate, as compared to tropical, regions. Three main groups can be considered which include Ingoldian fungi, aquatic ascomycetes and non-Ingoldian hyphomycetes, chytrids and, oomycetes. The fungi occurring in lentic habitats mostly differ from those occurring in lotic habitats. Although there is no comprehensive work dealing with the biogeography of all groups of freshwater fungi, their distribution probably follows that of Ingoldian fungi, which are either cosmopolitan, restricted to pantemperate or pantropical regions, or in a few cases, have a restricted distribution. Freshwater fungi are thought to have evolved from terrestrial ancestors. Many species are clearly adapted to life in freshwater as their propagules have specialised aquatic dispersal abilities. Freshwater fungi are involved in the decay of wood and leafy material and also cause diseases of plants and animals. These areas are briefly reviewed. Gaps in our knowledge of freshwater fungi are discussed and areas in need of research are suggested. 相似文献
17.
Leonard C. FerringtonJr. 《Hydrobiologia》2008,595(1):447-455
Chironomidae are common inhabitants of most aquatic habitats, and often dominate aquatic insect communities in both abundance
and species richness. Species occur in all continents, including Antarctica, and most major oceanic islands that have been
investigated. The family is divided into 11 subfamilies and 22 nominal tribes. Although individual species occur in a wide
range of habitats from terrestrial to fully aquatic, a total of 339 genera and 4,147 species are unambiguously aquatic in
their immature stages. Greatest species and generic richnesses occur in the Palaearctic Region and Nearctic Region, respectively,
but this pattern may largely reflect historical patterns of past taxonomic research efforts.
Guest editors: E.V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment 相似文献
18.
William J. Poly 《Hydrobiologia》2008,595(1):209-212
The Branchiura of freshwater habitats, consisting of the valid genera Argulus, Chonopeltis, Dipteropeltis, and Dolops, presently contains 113 valid species and 12 undescribed species. The entire group is composed of ectoparasitic species that
usually live on fishes. The highest diversity of genera and species occurs in the Afrotropical and Neotropical regions. The
diversity of the freshwater species surpasses that of species in marine and brackish waters, but this could be due to inadequate
study of the fauna of the latter habitats. One species, Argulus japonicus, has been introduced from east/southeast Asia to all other continents, except Antarctica. Studies of higher level relationships
place the Branchiura with either Pentastomida or Ostracoda. Hypotheses about phylogenetic relationships of either the genera
or species in this group have not been proposed.
Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment
The present paper was intended as a very brief overview of the known diversity of the Branchiura in freshwaters only, and
regrettably is deficient in mention of much information and many relevant citations pertaining to the group. 相似文献
19.
Global diversity of fish (Pisces) in freshwater 总被引:1,自引:0,他引:1
The precise number of extant fish species remains to be determined. About 28,900 species were listed in FishBase in 2005,
but some experts feel that the final total may be considerably higher. Freshwater fishes comprise until now almost 13,000
species (and 2,513 genera) (including only freshwater and strictly peripheral species), or about 15,000 if all species occurring
from fresh to brackishwaters are included. Noteworthy is the fact that the estimated 13,000 strictly freshwater fish species
live in lakes and rivers that cover only 1% of the earth’s surface, while the remaining 16,000 species live in salt water
covering a full 70%. While freshwater species belong to some 170 families (or 207 if peripheral species are also considered),
the bulk of species occur in a relatively few groups: the Characiformes, Cypriniformes, Siluriformes, and Gymnotiformes, the
Perciformes (noteably the family Cichlidae), and the Cyprinodontiformes. Biogeographically the distribution of strictly freshwater
species and genera are, respectively 4,035 species (705 genera) in the Neotropical region, 2,938 (390 genera) in the Afrotropical,
2,345 (440 genera) in the Oriental, 1,844 (380 genera) in the Palaearctic, 1,411 (298 genera) in the Nearctic, and 261 (94
genera) in the Australian. For each continent, the main characteristics of the ichthyofauna are briefly outlined. At this
continental scale, ichthyologists have also attempted to identify ichthyological ‘‘provinces’’ that are regions with a distinctive
evolutionary history and hence more or less characteristic biota at the species level. Ichthyoregions are currently identified
in each continent, except for Asia. An exceptionally high faunal diversity occurs in ancient lakes, where one of the most
noteworthy features is the existence of radiations of species that apparently result from intra-lacustrine speciation. Numerous
fish-species flocks have been identified in various ancient lakes that are exceptional natural sites for the study of speciation.
The major threats to fish biodiversity are intense and have been relatively well documented: overexploitation, flow modification,
destruction of habitats, invasion by exotic species, pollution including the worldwide phenomena of eutrophication and sedimentation,
all of which are interacting.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens
Freshwater Animal Diversity Assessment 相似文献
20.