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1.
The relationship between algal communities’ species diversity and the catchment of rivers in the southern Russian Far East has been studied. The number of species, varieties, and forms of algae increased significantly according to the increase in the head river area up to 80–100 km2; then this number slowed down dramatically. In general, the relationship between the number of algal taxa (D) and the catchment of the river (S, km2) was described as D = 91.6S 0.194 (R 2 = 0.97).  相似文献   

2.
The marine benthic algal flora of Clare Island, off County Mayo, western shore of Ireland, was investigated; collections of intertidal and subtidal marine algae were made at 16 sites along the eastern and southern shores in the years 1990, 1993 and 2000–2002. The data and observations obtained were compared with the results of a similar survey conducted by Arthur Disbrowe Cotton in 1910–1911. Considering the results of the original survey and the new survey together, the marine algal flora of the island currently totals 293 species; 224 species were recorded by Cotton in the original survey, whereas 223 species were identified in the present study. Most species are common to the original and the new list and the main differences are easily explainable; the new survey used SCUBA diving, which allowed the collection of several subtidal species not collected in 1910, and Cotton reported several microscopic green and brown algae, usually difficult to recognise in the field, which were not rediscovered. The most remarkable differences consist in the current presence of some large intertidal brown algae (Bifurcaria bifurcata, Cystoseira foeniculacea and Cystoseira nodicaulis) that were not reported in the survey of 1910. Two algae, Codium fragile subsp. tomentosoides and Asparagopsis armata, were introduced in Europe after the original survey. At present, the benthic algal assemblages of Clare Island still have basically the same structure and distribution as in 1910 and, if compared with other coastal areas of Europe, the intertidal marine environment of Clare Island appears remarkably well conserved.  相似文献   

3.
Using cell suspension ability as an indicator, we studied the inhibitory effect of garlic (Allium sativum) and diallyl trisulfide on six species of red tide causing algae. This included: the inhibition by 0.08% garlic solution of five algal species — Alexandrium tamarense, Scrippsiella trochoidea, Alexandrium catenella, Alexandrium minutum and Alexandrium satoanum; the effects of garlic concentration on the inhibition of A. tamarense, S. trochoidea and Chaetoceros sp.; the effects of inhibitory time on the rejuvenation of algal cells; and the effects of heating and preservation time on algal inhibition by garlic solution. In addition, whether or not the ingredients of garlic solution had a possible algicidal effect was studied by comparing inhibition of A. tamarense by garlic solution and man-made diallyl trisulfide. The results showed that 1) inhibition by garlic solution was significant on A. tamarense, A. satoanum, A. catenella and S. trochoidea, and the least effective was a concentration of 0.04% on A. tamarense and S. trochoidea. Moreover, the higher the concentration, the stronger was the inhibition, and a high inhibitory rate (IR) could be maintained for at least three days when the garlic concentration was above 0.04%. For A. tamarense, it was also found that the longer the inhibitory time and the higher the concentration, the lower was the rate of resumed cell activity. On the contrary, garlic solution could not inhibit A. minutum or Chaetoceros sp.; 2) The IR to A. tamarense was reduced slightly as the heating time of the garlic solution was lengthened, but the average IR was still above 80%. There was no significant difference between the IR of the supernatant and sediment of the garlic solution. Furthermore, no change of algal inhibition was found when the garlic solution was preserved at 20°C for several days; 3) As with garlic solution, diallyl trisulfide inhibited A. tamarense strongly; the IR was above 93% and was maintained for at least three days, as long as the concentration was 3.2–10.0 mg L−1. Thus, diallyl trisulfide may have been the major ingredient in garlic solution which inhibited the algae but, in addition, more than one ingredient may have been inhibiting the algae. In conclusion, garlic was a good algal inhibitor with many advantages, such as being common, cheap, non toxic and with high efficiency, and diallyl trisulfide, one of the components of garlic, was similarly effective in algal inhibition. It would be useful, therefore, to further study garlic as an environmentally friendly algal inhibitor.  相似文献   

4.
Temperature tolerance (1 week exposure time) was determined at intervals during two successive years in 54 dominant marine benthic algae growing near Helgoland (North Sea). Seawater temperatures near Helgoland seasonally range between 3°C (in some years 0°) and 18°C. All algae survived 0°C, and none 33°C. Among the brown algae,Chorda tomentosa was the most sensitive species surviving only 18°C, followed by theLaminaria spp. surviving 20°, however not 23°C.Fucus spp. andCladostephus spongiosus were the most heat-tolerant brown algae, surviving 28°C. Among the red algae, species of the Delesseriaceae(Phycodrys rubens, Membranoptera alata) ranged on the lower end with a maximum survival temperature of 20°C, whereas the representatives of the Phyllophoraceae(Ahnfelitia plicata, Phyllophora truncata, P. pseudoceranoides) exhibited the maximum heat tolerance of the Helgoland marine algal flora with survival at 30°C. The latter value was also achieved byCodium fragile, Bryopsis hypnoides andEnteromorpha prolifera among the green algae, whereas theAcrosiphonia spp. survived only 20°C, andMonostroma undulatum only 10°C, not 15°C. Seasonal shifts of heat tolerance of up to 5°C were detected, especially inLaminaria spp. andDesmarestia aculeata. The majority of the dominant marine algal species of the Helgoland flora occurs in the Arctic, and it is hypothesized that also there the upper lethal limits of these species may hardly have changed even today. The data presented should provide a base for further analysis of the causes of geographical distribution of the North Atlantic algal species, but have still to be supplemented with similar investigations on other coasts, and supplemented with determinations of temperature requirements throughout the life cycle.Paper presented at the Seaweed Biogeography Workshop of the International Working Group on Seaweed Biogeography, held from 3–7 April 1984 at the Department of Marine Biology, University of Groningen (The Netherlands). Convenor: C. van den Hoek  相似文献   

5.
Five sympatric colour varieties of the hoplonemertean Tetrastemma nigrifrons (var. pallidum, var. bicolor, var. purpureum, var. punctata, var. albino) were found in Vostok Bay (the Sea of Japan). The taxonomic status of the varieties, some of which have been known for almost a century, was uncertain. Starch gel electrophoresis was used to compare allele frequencies of these varieties at 19 isozyme loci. Neither fixed allelic differences nor statistically significant differences in allele frequencies between different colour varieties was revealed. It was concluded therefore that all the colour varieties studied are conspecific. As estimated from the electrophoretic screening of 24 isozyme loci, the species is highly variable at the molecular level. It has high mean values of observed and expected heterozygosity estimates, H o =0.313 ± 0.049 and H e =0.323 ± 0.050, and is one of the most variable species among invertebrates.  相似文献   

6.
Phytoplankton samples were collected from ice-covered Utah Lake during February and March, 1979 in order to characterize the winter algal flora. These samples were analyzed for presence and abundance of diatoms and non-diatom algae as well as selected water chemical parameters. A total of 159 diatom taxa and 20 non-diatoms was found in the water column under the ice. The flagellates Carteria stellifera, Euglena gracilis and Chlamydomonas globosa dominated the winter non-diatom flora while Stephanodiscus cf. dubius, Cyclotella meneghiniana, Navicula minima, Fragilaria construens var. venter, and Melosira granulata var. angustissima dominated the winter diatom flora. Species richness and abundance were elevated in the major bays of the lake.  相似文献   

7.
Dr. Saleh M. Okla 《Facies》1992,27(1):217-223
Summary Late Permian bioclastic calcarenite beds of the middle Khuff Formation were sampled for their algal constituents near the city of Unayzah, Quassim district in central Saudia Arabia. The algal flora includes two species of udoteacean algae (Succodium difficile andSuccodium sp.), the dasycladacean algaMizzia velebitana and two species of red algae (Gymnocodium bellerophontis, Permocalculus plumosus). Other algal floral remains found forming isolated single layers which have generally been named algal microfacies. These include a phylloid microfacies, an oncoid microfacies and algal stromatolites. The Khuff Formation is well-known for its accumulation of non-associated gas and particularly for its oil accumulation in eastern Saudi Arabia and the Arabian Gulf states.  相似文献   

8.
9.
Synopsis Algal growth and damselfish (Eupomacentrus planifrons) territories were studied in two reef habitats at Discovery Bay, Jamaica. Damselfish territories were contiguous in the reef flat (0 to 2.5 m), where the algal composition and biomass varied from territory to territory. In contrast, on the lower reef terrace (22 m), damselfish territories were often spatially segregated. While the algal composition of the territories was more uniform on the reef terrace, the total algal biomass was lower than in the territories on the reef flat. Damselfish are largely herbivorous, and they defend their territories against most intruding fish, including a number of herbivorous species. Areas of the reef terrace outside of damselfish territories were heavily grazed by herbivorous fishes and contained only small quantities of non-crustose algae.The reef terrace territories were characterized by a multispecific turf of algae (greens, blue-greens, and reds) covering the Acropora cervicornis framework and by the leafy, brown alga, Lobophora variegata. A rapid reduction in the biomass of brown algae and filamentous algae was noted when damselfish were permanently removed from their territories. Only calcified, encrusting algae — plants apparently somewhat undesirable as fish food sources — would be common on the terrace zone of this reef if damselfish territories were absent. Damselfish territoriality may significantly influence the dynamics of some reefs by increasing the biomass of the algal turf thereby increasing; reef productivity. Since blue-green algae, potential nitrogen fixers, occur in these algal turfs, the fish may also be indirectly affecting reef nutrition.  相似文献   

10.
The importance of algae in the diet of the oligochaetesArcteonais lomondi, Uncinais uncinata andLimnodrilus claparedeianus was determined from May 1978 to April 1979 in two lakes located in northern Canada. The lakes were small (130–157 ha), shallow, (<15 m) and mesotrophic. During summer, algae accounted for up to 57–75% by volume of ingested matter inA. lomondi andU. uncinata depending on lake whereas in winter the corresponding range was 10–22%. Dominant algae found in the gut included the diatomsSurirella robusta, Diploneis puella, Amphora ovalis, Stephanodiscus astraea, Fragilaria construens andAchnanthes minutissima. Although the same taxa were ingested byL. claparedeianus, algae always represented <5% by volume of the gut contents. This possibly reflects subsurface feeding in an area where algae were rare. The length distribution of ingested diatoms, ranging from 9 to 250 m, was similar regardless of species in both lakes. Hence, there was no partitioning of algal food resources among oligochaetes.  相似文献   

11.
The electron microscopy study of algae from Lake Elgygytgyn and the water bodies of its basin has revealed 21 taxa of centric diatoms of specific and intraspecific ranks. Nine new species and varieties have been found, including Aulacoseira distans var. nivaloides, A. distans var. septentrionalis, Discostella guslyakovyi, which are rare for the flora of Russia; an endemic species (?) Pliocaenicus seckinae; and six interesting forms from the genus Aulacoseira identified only to the genus. The list of Centrophyceae of Beringia has been broadened.  相似文献   

12.
Group foraging of the algae eating cichlid,Petrochromis fasciolatus, was studied along a rocky shore in Lake Tanganyika, in an area occupied by the feeding territories of several herbivorous cichlid species. SolitaryP. fasciolatus or schools comprising a few members only were nearly always repelled from such territories, although larger schools (40–250 individuals) ofP. fasciolatus were able to overwhelm the defenses of territory owners and enable subsequent foraging. The frequency and duration of individual foraging sessions on the algal mats were positively correlated with group size, probably owing to individuals in large schools suffering fewer attacks from territory owners. Almost all of the foraging sites ofP. fasciolatus were inside the territories of other herbivorous cichlids, especially those ofNeolamprologus moorii (more than 80% of total), in which the algal density was more than 10 times that in territories of the other species.N. moorii territories included only 4% rocky substrate, indicating that schools ofP. fasciolatus selectively chose territories containing rich resources.  相似文献   

13.
In the last decades, numerous exotic species of microalgae have been found in the continental waters of Europe. In three natural shallow lakes located in the southwest of France, several planktonic species typically encountered in tropical areas were observed during 2006 and 2007. The most representative taxa were Planktolyngbya microspira Kom. & Cronb. P. circumcreta (G. S. West) Anagn. & Kom., Cyanodictyon tropicale Senna, Delazari & Sant’Anna and Staurastrum excavatum var. planctonicum Krieg. These species had so far only been reported from African lakes and other tropical areas, but in this study they accounted for up to 58 and 12% of the total abundance and biomass, respectively, during spring and summer. Some of these lakes were studied in the 1970s and only exotic desmids were reported; but at that time, the three cited cyanobacteria were not described yet. Waterfowl are considered as the main dispersers because they migrate over long distances, transporting algae on the feet and feathers or in the digestive tract. In fact, the Aquitaine Region is one of the main bird migration corridors in Europe. Survival of cyanobacteria, diatoms and desmids carried by birds could be possible due to resting stages, sheaths investments or vegetative cells. In addition, global warming may have contributed to the success of these tropical species in temperate lakes. Indeed, minimal temperatures have increased significantly in the Aquitaine region over the last 30 years and could have played a key role in algal survival through winter.  相似文献   

14.
The red alga Pachymeniopsis lanceolata, formerly known as Grateloupia lanceolata, is a component of the native algal flora of northeast Asia and has been introduced to European and North American waters. It has been confused with a cryptic species collected from Korea and Italy. Our analyses of rbcL, cox3 and ITS from P. lanceolata and this cryptic species has revealed two distinct entities, forming a clade, which were clearly separated from its congeners and positioned with other Asian species. Here, we describe the cryptic species as P. gargiuli sp. nov., a species that differs from others by molecular sequence and subtle anatomical characters. We hypothesize that P. gargiuli may have been recently dispersed by anthropogenic vectors, possibly at or near the same time as was P. lanceolata. Our cox3 data set revealed that one haplotype of P. gargiuli, shared between Korea and Italy, and two haplotypes of P. lanceolata, commonly occurring in Korea and USA, are invasive haplotypes. This is the first report of the utility of the mitochondrial coding cox3 sequences in red algae.  相似文献   

15.
Comparative studies were carried out on the adsorption of copper by a range of laboratory-cultured algae and freshwater phytoplankton samples. The level of surface mucilage associated with the cultured algae ranged from high (Anabaena spiroides, Eudorina elegans) to moderate (Anabaena cylindrica, Microcystis aeruginosa) to complete absence (Chlorella vulgaris, Asterionella formosa, Aulacoseira varians, Ceratium hirundinella). With laboratory cultures, the rapid uptake, EDTA release and quantitative similarity between living and dead (glutaraldehyde-fixed) algae were consistent with physical binding of Cu at the cell surface. The higher Cu adsorption per unit surface area and longer adsorption time of mucilaginous algae in the time-course study, and the relatively high level of Cu bound to mucilage found by X-ray microanalysis suggest that mucilage played an important role in metal binding. For all species examined, Cu adsorption kinetics (external Cu concentrations 1 to 1000 mg L−1) showed a clear fit to the Freundlich, but not the Langmuir isotherm, indicating a monolayer adsorption model with heterogenous binding sites. The Freundlich adsorption capacity constant (Kf) was higher in mucilaginous (3.96–12.62) compared to nonmucilaginous (0.36–3.63) species, but binding intensity (Freundlich constant 1/n) did not differ between the two cell types. The results suggest that mucilaginous algal species may have potential as biosorbents for treatment of industrial effluents containing heavy metals. Investigation of the Cu adsorption behavior of four mixed phytoplankton samples also revealed a good fit to the Freundlich, but not the Langmuir, isotherm. Freundlich constants were in the range 2.3–3.2 for samples dominated by Chlorophyta, Bacillariophyta and Cyanophyta, but recorded a value of 7.4 in the sample dominated by Dinophyta. Comparison with data from laboratory monocultures suggested that the adsorption kinetics of mixed environmental phytoplankton samples cannot be predicted simply in terms of the major algal species.  相似文献   

16.
We isolated and identified strains of marine and freshwater planktonic and benthic microalgae from the vicinity of Indian River County, Florida (≈27.5°N, 80.34°W), cultivated them in batch culture, and examined their allelopathic activity against mosquito larvae. Additional algal material was obtained from Syracuse University and the University of Texas—Austin Algal Culture Collection. Mosquito larvae (Aedes aegypti (L.)) from colonies maintained at the Florida Medical Entomology Laboratory were challenged with the microalgae using log-growth phase and senescent-phase cultures. Appropriate controls (no algae) were used for each treatment. There were no significant differences in development time between treatments across all trials and a few significant treatment effects on development times, mortality, or mosquito size in the individual trials; however, there was a tendency for treatments with senescent microalgae to develop faster than controls with no algae. Effects consistent with algal toxicity included the two trials with Microcystis aeruginosa, where the larvae exposed to the strain-producing microcystin had significantly longer development times than the controls or those grown with the non-microcystin-producing strain, and the trial with the dinoflagellate Akashiwo sanguinea, where larvae exposed to this species had significantly higher mortality than the controls. No consistent patterns or differences between experimental and control treatments in the value of λ′, an estimate of the population finite rate of increase, were discernible from the data.  相似文献   

17.
Model experiments on a possibility that pathogenic enterobacteria Salmonella enteritidis (Gartneri) can grow on decaying algal mats with prevalence of the filamentous algae Cladophora glomerata (L.) Kütz were carried out. Samples of algal mats have been collected in the eastern part of the Gulf of Finland in the Baltic Sea. A bacterial culture of Salmonella enteritidis was placed into tubes containing samples of mats. The intensive growth of salmonella was noted in alga samples collected in the freshwater zone (salinity 0.2–1.5‰); growth was practically absent in the samples of algae collected in a zone with salinity 2–3‰, while salmonella remained viable in the control tubes with water without algae. The growth of coliform enterobacteria initially inhabited in the algal mats was discovered in all experiments. Studies carried out in 2009 show that the thickness of the algal mats in the costal zones of the Gulf of Finland reached 20 cm and their biomass reached a few tons per 1 km2. These experiments showed that dead algal mats stimulate the growth of enterobacteria in the littoral zone of the Baltic Sea, especially in the freshwater part, and can promote the development of these pathogenic microorganisms.  相似文献   

18.
19.
In contrast to the well-known blue-green algal containing lichens several green algal containing lichens, belonging to very different genera, show regular connections to free-living or ± lichenized blue-green algae, mainlyStigonema. Most of these lichens have squamulose thalli. This lichen-algal relationship, regarded as cyanotrophy, may be either facultative or obligate. Some of the species occur only on very poor, acidic rocks onStigonema, while they occur independent ofStigonema in high nutrient biotops. Obligate species cover the blue-green algae with hyphae and some of these species cover the algae so extensively that one can call these connections paracephalodia. — Two species and one variety are new to science from the mainly Himalayan genusBryonora. They occur in high elevations in Nepal and are cyanotrophic.Bryonora selenospora has thick, halfmoon-shaped to slightly twisted ascospores. The other two new taxa areB. reducta andB. rhypariza var.cyanotropha. There are several other cyanotrophic lichen taxa besides the ones described here. They will be introduced at a later occasion.
Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.  相似文献   

20.
The diatom population structure of a salt marsh epiphytic community growing on Enteromorpha intestinalis was studied at one station throughout the summer. A total of 218 species or varieties were recognized. Six species— Fragilaria construens, Cocconeis scutellum, Cocconeis placentula, Achnanthes hauckiana varieties, Achnanthes pinnata, and Amphora coffeaeformis (var. acutiuscula)–dominated the Enteromorpha epiphytic community during the summer months and comprised ∼ 40% of the total populations. Melosira nummuloides, Opephora martyi, Synedra fasiculata var. tabulata, S. affinis, Navicula platyventris, and N. pavillardi were also very common species (13% of the total population). The distribution of many species in the community was seasonal. A series of differential media have been developed which are effective as tools for the isolation and nutritional characterization of the algae and bacteria from the community. Many diatom species can be recognized by their colony type or growth pattern on solidified media. A key and illustrated plates aid in identification. Changes in population structure of the community were reflected by changes in the nutritional patterns as judged by differences in the growth of diatoms and bacteria on the differential media tested. The nutritional requirements, selectivity, and rank order of media for individual species is given. Almost half of the colony types (32–33) grew on either unenriched seawater from the collection site or basal synthetic seawater. Erdschreiber was a poorer medium for the isolation of algae than seawater alone. Few algal colonies grew on either marine nutrient agar or trypticase soy agar. Nitrite inhibited algal growth. Media enriched with thiamine, biotin, or nitrate, phosphate, and B12 were stimulatory. Soil extract or an acetone extract of Enteromorpha tripled growth; a complex vitamin mixture, or glycerol, or mannitol, or an autoclaved extract of Enteromorpha doubled colony numbers. The greatest numbers of diatom types (43) and total colonies (655) were recovered on media enriched with acetone extract of Enteromorpha, suggesting a possible nutritional relationship between Enteromorpha and its epiphytes. The representativeness of the isolations from the natural community as a function of time was also considered. Concentrations of selected dissolved potential growth-stimulating nutrients were measured within and external to Enteromorpha communities. We conclude that the algal assemblage growing epiphytically on Enteromorpha intestinalis has a diverse auxotrophic profile which contributes to the productivity and stability within this important component of the epiphytic community and that much of the organic substrates used by individual species originate within and are recycled among the community members.  相似文献   

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