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1.
浙江近海后鳃类软体动物的分布及其区系   总被引:1,自引:0,他引:1  
报道了浙江近海的后鳃类97种,分别隶属于7目30科44属。其中我国沿岸广温广布种14种,主要分布于东海和南海的亚热带种50种,南海的热带种18种,渤、黄海延伸到东海北部的暖温带种15种。  相似文献   

2.
Eighteen opisthobranch species are described and illustrated from the Sudanese Red Sea, including seven new species, one new subspecies and three species for which this is the first Red Sea record. Eleven bullomorphs, four pleurobranchomorphs, four sacoglossans and four phyllidiid mudibranchs are now known from the Red Sea. There appears to be a high percentage of endemic species in the Red Sea. This is what one might expect, in view of the conditions of near isolation, low temperatures and high salinity that prevailed in this sea 13000 23000 years ago. Of the groups discussed in this paper, one Red Sea species has invaded the Mediterranean Sea, and one Mediterranean species has invaded the Red Sea, since the opening of the Suez Canal in 1867. Many Red Sea species are very colourful, in comparison to Mediterranean ones. This could perhaps be because Red Sea waters are cleaner, thereby favouring the evolution of greater precision in colour markings.  相似文献   

3.
Eighteen opisthobranch species are described and illustrated from the Sudanese Red Sea, including seven new species, one new subspecies and three species for which this is the first Red Sea record. Eleven bullomorphs, four pleurobranchomorphs, four sacoglossans and four phyllidiid mudibranchs are now known from the Red Sea.
There appears to be a high percentage of endemic species in the Red Sea. This is what one might expect, in view of the conditions of near isolation, low temperatures and high salinity that prevailed in this sea 13000 23000 years ago.
Of the groups discussed in this paper, one Red Sea species has invaded the Mediterranean Sea, and one Mediterranean species has invaded the Red Sea, since the opening of the Suez Canal in 1867.
Many Red Sea species are very colourful, in comparison to Mediterranean ones. This could perhaps be because Red Sea waters are cleaner, thereby favouring the evolution of greater precision in colour markings.  相似文献   

4.
A biogeographic analysis of the Black Sea and Caspian Sea basin and adjacent Aegean Sea and the Sea of Marmara was conducted based on the distribution of 55 mysid species. The Black and Caspian Sea basin proper is inhabited by 35 mysid species belonging to 12 genera, among them 26 species and 3 genera are endemic to the region. Ponto-Caspian and Caspian species are predominant. The explored areas were included into two provinces of the Mediterranean subrealm of the East-Atlantic Subtropical realm and three provinces of the Ponto-Caspian realm.  相似文献   

5.
Analysis of trawl catches in the southeastern Barents Sea was performed for the period of 1980–2008. One lamprey and 48 fish species were defined, including 38 marine fish species, 8 anadromous and amphidromous species, and 1 freshwater species. The ichthyofauna of several areas of the southeastern Barents Sea was described (Cheshskaya Inlet, Pomorskiy Strait, southeastern Pechora Sea, Pechora Sea, Khaipudyrskaya Inlet and adjacent areas). Biodiversity indexes and Shannon Index were applied to describe the species diversity. Cluster analysis was applied to compare the species lists from different areas. Multiyear dynamics of ichthyofauna was studied. The tendency of geographical range expansion eastward was observed for boreal species.  相似文献   

6.
Abstract . This paper assesses variation in coral species diversity within the Indonesian archipelago, and the influence of regional species pools, geomorphology and anthropogenic pollution on coral species diversity and occurrence. We obtained transects from 33 sites on 14 reefs in three regions of Indonesia: Ambon (Moluccas), South Sulawesi and the Java Sea. We determined the within‐site species richness by using species‐sampling curves. Cluster analysis and multi‐dimensional scaling showed that land‐based pollution was the primary determinant of coral species diversity and species occurrence on reefs. Relatively unaffected reference sites in eastern Indonesia were approximately 20% more diverse than Java Sea reference sites. Rare species formed a higher proportion of the coral fauna on eastern Indonesian sites, and eastern Indonesian apparent endemic species contributed approximately 25% of the total species pool sampled. Between‐site variation in species occurrence was lower on Java Sea reefs than on eastern Indonesian reefs. A larger species pool in eastern Indonesia than in the Java Sea probably accounted for most of the difference in within‐site species diversity between eastern Indonesian and Java Sea reference sites. High fishing intensity in the Java Sea, including destructive fishing practices, may have also contributed to reduced within‐site species diversity on Java Sea reference reefs. Despite the fact that the Java Sea was exposed during Pleistocene lowstands, and was recolonized by marine organisms only within the last 10 000 years, coral species diversity and assemblage composition on the Java Sea reefs was largely similar to open ocean reefs in eastern Indonesia.  相似文献   

7.
A variety of filamentous fungi have recently been isolated from the Dead Sea (340 g/L total dissolved salts). To assess the extent to which such fungi can survive for prolonged periods in Dead Sea water, we examined the survival of both spores and mycelia in undiluted Dead Sea water and in Dead Sea water diluted to different degrees with distilled water. Mycelia of Aspergillus versicolor and Chaetomium globosum strains isolated from the Dead Sea remained viable for up to 8 weeks in undiluted Dead Sea water. Four Dead Sea isolates (A. versicolor, Eurotium herbariorum, Gymnascella marismortui, and C. globosum) retained their viability in Dead Sea water diluted to 80% during the 12 weeks of the experiment. Mycelia of all species survived for the full term of the experiment in Dead Sea water diluted to 50% and 10% of its original salinity. Comparison of the survival of Dead Sea species and closely related isolates obtained from other locations showed prolonged viability of the strains obtained from the Dead Sea. Spores of isolates obtained from the terrestrial shore of the Dead Sea generally proved less tolerant to suspension in undiluted Dead Sea water than spores of species isolated from the water column. Spores of the species isolated from the control sites had lost their viability in undiluted Dead Sea water within 12 weeks. However, with the exception of Emericella spores, which showed poor survival, a substantial fraction of the spores of Dead Sea fungal isolates remained viable for that period. The difference in survival rate between spores and mycelia of isolates of the same species points to the existence of adapted halotolerant and/or halophilic fungi in the Dead Sea.  相似文献   

8.
A total of 23 species and three groups of form variants of oncaeidcopepods have been identified, which were collected in smallmesh net samples taken along a transect from the northernmostRed Sea (>27°N) to the Gulf of Aqaba down to a maximumdepth of 800 m. Two of the species were present only in theRed Sea main basin, but were not recorded in the Gulf. By comparingthe present results with previously published data from thecentral and southern Red Sea a first assessment of the zoogeographicaldistribution of Oncaeidae in the entire Red Sea has been achieved.The species diversity of Oncaeidae in the Gulf of Aqaba appearsto be considerably lower compared to the southern Red Sea, where31 oncaeid species and four groups of form variants have beenfound. The observed latitudinal gradient in species numbersof Oncaeidae generally corresponds to the gradients observedfor various other zooplankton taxa in the Red Sea. First dataon the vertical distribution of oncaeid species in the Gulfare provided.  相似文献   

9.
The composition, distribution and seasonal variation of the benthic marine algae in the northern Bohai Sea coast were studied. 119 species of benthic marine algae were found in the northern Bohai Sea coast. They belong respectively to Cyanophyta, Thodophyta, Phaeophyta and Chlorophyta. The study showed that the marine algae flora of the northern Bohai Sea coast belongs to warm temperate in nature with considerable subtropical composition. There were 57 species of economic algae in the northern Bohai Sea coast and 7 newly recorded species.  相似文献   

10.
渤海北部底栖海藻的初步研究   总被引:11,自引:0,他引:11  
报道了渤海北部底栖海藻的种类组成、区系性质、群落结构和季节性变化。经调查,该海区隶属于蓝藻门、红藻门、褐藻门和绿藻门的底栖海藻共有119 种,其中包括57 种经济海藻和7 个新记录种。研究表明,渤海北部底栖海藻的温度性质以暖温带性为主,带有一定的亚热带性;其群落成分的季节性变化非常明显  相似文献   

11.
楚科奇海及白令海大型底栖生物初步研究   总被引:8,自引:0,他引:8  
1999年夏季在楚科奇海、白令海采用30 cm×30 cm箱式取样器,取得16个站位大型底栖生物定量样品。经分析研究有大型底栖生物92科164种,其中多毛类、软体动物和甲壳动物种数最多,占总种数的88.41%,三者构成北极楚科奇海和白令海大型底栖生物的主要类群。优势种有独毛虫属一种(Tharyx sp.) 、齿吻沙蚕属一种(Nephtys sp.)、囊叶齿吻沙蚕(Nephtys caeca)、平滑胡桃蛤(Ennucula tenuis)、短吻状蛤(Nuculana pernula pernuloides)、拟猛钩虾属一种( sp.)、日本沙钩虾(Byblis japonicus)和萨氏真蛇尾(Ophiura sarsii)等。楚科奇海和白令海大型底栖生物平均生物量为111.83 g/m2,平均栖息密度为2538个/m2。生物量和栖息密度均以多毛类和软体动物占多数。楚科奇海和白令海大型底栖生物有5个群落类型:Ⅰ. 梯额虫(Scalibregma inflatum)-紫轮参(Polycheira rufescens)-结栉盖蛇尾(Stegophiura nodosa)群落, Ⅱ. 拟单指虫(Cossurella sp.)-平滑胡桃蛤-鳞甲钩虾(Lepidepecreum sp.)群落, Ⅲ. 缩头竹节虫(Maldane sarai)-葛氏希泊钩虾(Hippomedon gorbunovi)-萨氏真蛇尾群落, Ⅳ.齿吻沙蚕(Nephtys sp.)-平滑胡桃蛤-日本沙钩虾-戈芬星虫(Golfingia sp.)群落和白令海群落, 即索沙蚕(Lumbrineris fragilis)-户枢蛤(Asthenothaerus sp.)-太平洋方甲涟虫(Eudorella pacifica)-革囊星虫(Phascolion sp.)群落。楚科奇海的群落Ⅰ、群落Ⅱ和白令海各群落结构相对稳定;楚科奇海群落Ⅲ和群落Ⅳ出现一定扰动。  相似文献   

12.
The subfamily Lycodinae is represented in the Sea of Japan by two genera (Lycodes and Petroschmidtia) and seven species (Lycodes japonicus, L. nakamurae, L. raridens, L. tanakae, L. teraoi, L. yamatoi, and Petroschmidtia toyamensis), which are widely distributed on the shelf and upper continental slope. Based on the geographic and bathymetric distribution of eelpouts of the Sea of Japan and adjacent waters, two groups of closely related species with different types of distribution ranges were distinguished. The first group includes pairs of species that live primarily on the continental slope and are completely isolated in the Sea of Japan or in the Sea of Okhotsk. The second group is comprised of upper interzonal species of the Sea of Japan that are found on the continental slope and shelf, as well as in the southern Sea of Okhotsk from Terpeniya Bay to the southern Kuril Islands. Their related species in the Sea of Okhotsk are mostly found to the north of the Terpeniya Bay. The study of the eelpout distribution and the data on the geological history and paleoclimate of the Far East show that the Lycodinae fauna of the Sea of Japan was formed from North Pacific eelpout-like fishes during the isolation of the sea in the late Pliocene-early Pleistocene, which was concomitant with the general cooling of the Earth’s climate. During the Pleistocene interglacials, the eelpout migrations were unidirectional, from the Sea of Japan to the southern Sea of Okhotsk. The reconstruction of the formation of the Sea of Japan Lycodinae fauna suggests that the related taxa from the Sea of Japan and the Sea of Okhotsk are separate species, while the northern and southern forms of species from the Sea of Japan (Lycodes yamatoi and L. teraoi) are no more than subspecies.  相似文献   

13.
Aim Unique topographic features left the Red Sea and its north‐eastern extension into the Gulf of Aqaba practically devoid of coral‐reef‐based organisms during the last glacial maximum. The current ichthyofauna in these two ‘regions’ thus represents the product of relatively recent colonization by species found in the Arabian Sea, which adjoins the Red Sea at its southern tip. We used this system to test why some marine species seemingly fail to extend their geographic range, thereby generating spatial heterogeneity in biodiversity. Location The Arabian Sea, Red Sea, and the Gulf of Aqaba. Methods A list of coral‐reef‐associated fish species, belonging to the 10 most speciose families, was compiled for each region using published sources. The data were analysed (major axis regression, randomization tests) for taxonomic and body‐size‐dependent biases in colonization probabilities. A simple probabilistic model was used to examine the potential contribution of local (within‐region) extinctions to determining species composition in the Red Sea. Results Of the 462 reef‐associated species that inhabit the Arabian Sea, 69% have crossed successfully into the Red Sea; of these, 55% have crossed into the Gulf of Aqaba. A species’ probability of being found in either ‘target’ was independent of presumed innate differences, i.e. ecological correlates of taxonomic affiliation and body size. Similarly, local extinctions were found unlikely to have been of consequence over the past several thousand years. Main conclusions Present‐day differences in the species richness of reef‐associated fish species among the Arabian Sea, Red Sea and Gulf of Aqaba appear to be the product of external, non‐selective constraints on colonization. The random nature of the colonization process is suggestive of ecological redundancy among coral‐reef fish species. Importantly, the study places a time frame on the processes that determine spatial patterns of biodiversity in reef fish.  相似文献   

14.
中国沿海海鞘的物种多样性   总被引:25,自引:0,他引:25  
郑成兴 《生物多样性》1995,3(4):201-205
至今,中国海已经记录了66种海鞘。其中,渤海有5种,黄海21种,东海24种,南海53种。种类分布从北往南逐渐递增,柄瘤海鞘在黄海、渤海数量很大(8100个/m2),但往南分布,未发现超过罗源湾。皱瘤海鞘在南海数量很大(2225个/m2),往北也未发现超过罗源湾。玻璃海鞘和乳突皮海鞘在全国沿海都有分布。  相似文献   

15.
The species composition and brief characteristic of some elements of structure of the ichthyofauna of the Barents Sea within its geographic boundaries are represented. During the whole historic period of observations in the Barents Sea, 182 species and subspecies of fish were recorded, belonging to 59 families, 28 orders, and 5 classes. Most species and subspecies belong to the boreal complex (59.3%), occur principally in the bottom layers (56.6%), more than a half feed on bottom and demersal invertebrates (52.2%), and are commercial species (52.7%). In the Barents Sea, 21 species and subspecies are commercial. Their ration in catches depends on the integral impact of natural and anthropogenous factors. In the arctic zone of the Barents Sea, the part of noncommercial species makes by biomass 1.18%; in the boreal zone—0.26%; in the Pechora Sea—10.6%.  相似文献   

16.
Species movements in relation with global warming may increase the spatial overlap between exotic and endemic species, which is a critical issue for the conservation of biodiversity. The Mediterranean Sea, which is a receptacle for exotic species while being a hotspot for endemism, provides exceptional material for a case study. The aim of our study was to quantify (i) the increasing invasion from southern fish exotic species (Red Sea and Atlantic Ocean) that the Mediterranean biota is experiencing and (ii) the spatial overlap between exotic and endemic Mediterranean fish fauna following the northward movement of exotic species within the Mediterranean Sea in the context of global warming. The historical invasion dynamic of exotic fish species and the sea surface temperature series were reconstructed from 1810 to 2006 in order to estimate the correlation between invasion rate and climate. The geographical distributions of exotic and endemic fish richness before and after the period of global warming were used to assess the dynamic of spatial congruence. The results revealed (i) an acceleration of successful introductions from the Red Sea and (ii) the introduction of Atlantic species from lower latitudes in correlation with the increasing temperature of the Mediterranean Sea. We also showed an increasing overlap between the spatial distributions of endemic and exotic species richness. Taken together, our results suggest that endemic fish species are facing a growing number of exotic species because the Mediterranean Sea is acting as a catchment basin for southern species.  相似文献   

17.
An annotated checklist of free-living dinoflagellates (Dinophyceae) of the Black Sea, based on literature records, is reported and compared to the Mediterranean Sea and world oceans. Toxic species and/or responsible of harmful algal blooms (HAB) are marked in the checklist. From the 267 species (54 genera) listed nearly all taxa can be considered as cosmopolitan and no species as endemic. Several typically Arctic-boreal species (non recorded from the Mediterranean Sea) are reported from the Black Sea. The taxonomy and the biogeography of the taxa are discussed.  相似文献   

18.
Numerous planktonic species have disjunct distribution patterns in the world's oceans. However, it is unclear whether these are truly unconnected by gene flow, or whether they are composed of morphologically cryptic species. The marine planktonic chaetognath Sagitta setosa Müller has a discontinuous geographic distribution over the continental shelf in the northeastern Atlantic, Mediterranean Sea, and Black Sea. Morphological variation between these populations has been described, but overlaps and is therefore unsuitable to determine the degree of isolation between populations. To test whether disjunct populations are also genetically disjunct, we sequenced a 504-bp fragment of mitochondrial DNA comprising the cytochrome oxidase II region of 86 individuals. Sequences were highly variable; each represented a different haplotype. Within S. setosa, sequence divergence ranged from 0.2 to 8.1% and strong phylogeographic structure was found, with four main groups corresponding to the northeastern Atlantic, Mediterranean Sea (including Ligurian Sea, Tyrrhenian Sea and Gulf of Gabes), Adriatic Sea, and Black Sea. Two of these (Atlantic and Black Sea) were resolved as monophyletic clades, thus gene flow between disjunct populations of S. setosa has been extremely limited and lineage sorting has taken place. The deepest divergence was between Atlantic and Mediterranean/Black Sea populations followed by a split between Mediterranean and Black Sea populations. The Mediterranean/Black Sea clade comprised three groups, with the Adriatic Sea as the most likely sister clade of the Black Sea. These data are consistent with a colonization of the Black Sea from the Mediterranean. Furthermore, a possible cryptic species was found in the Black Sea with 23.1% sequence divergence from S. setosa. Two possibilities for the evolutionary origin of this species are proposed, namely, that it represents a relict species from the ancient Paratethys, or that it represents another chaetognath species that colonized the Black Sea more recently. Even though the exact timing of disjunction of S. setosa populations remains unclear, on the basis of the geological and paleoclimatic history of the European basins and our estimates of net nucleotide divergence, we suggest that disjunct populations arose through vicariance resulting from the cyclical changes in temperature and sea levels during the Pleistocene. We conclude that these populations have remained disjunct, not because of limited dispersal ability, but because of the inability to maintain viable populations in suboptimal, geographically intermediate areas.  相似文献   

19.
Cosmopolitan nature of the marine bryozoan Electra pilosa was studied to clarify geographic structure and to outline evolution and phylogeography of the species. Several local populations from the Northeast Atlantic (North Sea and Baltic Sea), Arctic (Barents Sea and White Sea) and Indo-West Pacific (New Zealand) were compared. In addition, we examined the closely related species E. posidoniae from the Mediterranean Sea. Phylogenetic analysis based on both 16S and 18S rDNA indicate that the Indo-West Pacific E. pilosa is a sister species to the Atlantic-Mediterranean clade, with the latter including the species E. posidoniae and the Atlantic population of E. pilosa. The topology of the phylogenetic tree leads us to conclude that E. pilosa is a paraphyletic species group relative to E. posidoniae, and a molecular dating of its divergence is consistent to geologic events associated with the closure of the Tethys Sea.  相似文献   

20.
Integral parameters of zooplankton community, including species diversity and its components were compared between the Chukchi Sea, Bering Sea, Sea of Okhotsk, Sea of Japan, and adjacent Pacific waters based on the data obtained by standard Juday net with a mouth area of 0.1 m2 during the large-scale surveys conducted by the Pacific Fisheries Research Center (TINRO Center) in 1984–2013. These parameters were calculated for the total surveyed area of approximately 7.0 million km2 and separately for each of the considered water bodies. In Pacific waters, species richness is higher than that in all the seas, while the concentration of individuals (expressed in terms of abundance, ind./m3) and evenness of their distribution over species were lower. The only sea with a larger mean size of organisms compared to the ocean is the Bering Sea. A lower species diversity than in the ocean has been recorded only from the Chukchi Sea; a lower density (in terms of biomass, g/m3) was determined only from the Sea of Japan. Among the four seas, the Chukchi Sea ranks first in terms of biomass and abundance of zooplankton, second in species evenness, third in the mean size of individuals, and last in species richness and diversity. The Bering Sea ranks first in terms of mean size of plankton organisms, second in species richness, diversity, and biomass, third in abundance, and last in species evenness. The Sea of Okhotsk ranks second in terms of mean size of individuals, last in their abundance, and third in the other parameters. The Sea of Japan ranks first in terms of species richness, evenness, and diversity, second in abundance, and last in mean size of zooplankton organisms, and, therefore, their biomass. The biomass of zooplankton, in accordance with the concentration of nutrients, increases in the southto-north direction (while its absolute abundance depends largely on the size of the body of water). The mean size of organisms increases in the same direction; the evenness of their distribution over species increases in the reverse direction (with the exception of both parameters for the Chukchi Sea). The rank of a water body for its biodiversity coincides with the species richness rank. The latter increases from north to south (except for the Okhotsk Sea), but greatly depends on the surveyed area and, even more, on the surveyed volume of water. A study of the literature data found some unexpected statistically significant relationships of the integral parameters of zooplankton with those of pelagic and bottom macrofauna, as well as with the parameters of zooplankton production, on the size of the considered bodies of water. The causes and the biological meanings of most of these relationships still do not have any rational interpretation. Their testing at other spatial scales will be continued in future works.  相似文献   

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