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1.
Yuwadee Peerapornpisal Sutthawan Suphan Neti Ngearnpat Jeeraporn Pekkoh 《Biologia》2008,63(6):852-858
The distribution of phytoplankton was investigated in standing water bodies such as reservoirs, ponds and marshes. Thirty
sampling sites in Northern Thailand were studied during 1998–2005. The water quality could be classified as oligotrophic-mesotrophic
to eutrophic status. Twelve families, 51 genera and 181 species of chlorophytic phytoplankton were found. The dominant genera
were Staurastrum spp., Cosmarium spp., Scenedesmus spp. and Pediastrum spp. The distribution of these species was mainly affected by the water quality.
Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia. 相似文献
2.
The faunistic composition of pelagic ostracods of regions situated to the north and northwest of the d’Urville Sea (60°–65°S,
148°–136° and 136°–113°E) is largely similar to that of the area adjacent to the Somov Sea at the same latitudes. Alacia hettacra is the most abundant species here; Austrinoecia isocheira, Boroecia antipoda, and Obtusoecia antarctica are common species. The maximum abundance of pelagic ostracods is observed in the 100–200 m depth range; the largest contribution
to it is contributed by A. hettacra. The number of species increases with increasing depth. The 64°–65°S region between 148° and 113° E is regarded as the northern
boundary of the “Polar Antarctic zone.” 相似文献
3.
I. H. Tomasco R. Del Río R. Iturriaga F. Bozinovic 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2010,180(6):877-884
Subterranean rodents construct large and complex burrows and spend most of their lives underground, while fossorial species
construct simpler burrows and are more active above ground. An important constraint faced by subterranean mammals is the chronic
hypoxia and hypercapnia of the burrow atmosphere. The traits, regarded as “adaptations of rodents to hypoxia and hypercapnia”,
have been evaluated in only a few subterranean species. In addition, well-studied subterranean taxa are very divergent to
their sister groups, making it difficult to assess the adaptive path leading to subterranean life. The closely related sister
genera Octodon and Spalacopus of Neotropical rodents offer a unique opportunity to trace the evolution of physiological mechanisms. We studied the ventilatory
responses of selected octodontid rodents to selective pressures imposed by the subterranean niche under the working hypothesis
that life underground, in hypoxic and hypercapnic conditions, promotes convergent physiological changes. To perform this study
we used the following species: Spalacopus cyanus (the subterranean coruros) and Octodon degus (the fossorial degus) from central Chile. Ventilatory tidal volume and respiratory frequency were measured in non-anaesthetized
spontaneously breathing animals. Acute hypoxic challenges (O2 1–15%) and hypercapnia (CO2 10%) were induced to study respiratory strategies using non-invasive whole body pletismography techniques. Our results show
that coruros have a larger ventilatory response to acute hypoxia as than degus. On the other hand, hypercapnic respiratory
responses in coruros seem to be attenuated when compared to those in degus. Our results suggest that coruros and degus have
different respiratory strategies to survive in the hypoxic and hypercapnic atmospheres present in their burrows. 相似文献
4.
This study tests population genetic patterns across the Eurasian dreissenid mussel invasions of North America—encompassing
the zebra mussel Dreissena polymorpha (1986 detection) and the quagga mussel D. rostriformis
bugensis (detected in 1990, which now has largely displaced the former in the Great Lakes). We evaluate their source-spread relationships
and invasion genetics using 9–11 nuclear microsatellite loci for 583 zebra mussels (21 sites) and 269 quagga mussels (12 sites)
from Eurasian and North American range locations, with the latter including the Great Lakes, Mississippi River basin, Atlantic
coastal waterways, Colorado River system, and California reservoirs. Additionally, mtDNA cytochrome b gene sequences are used to verify species identity. Our results indicate that North American zebra mussels originate from
multiple non-native northern European populations, whereas North American quagga mussels trace to native estuaries in the
Southern Bug and Dnieper Rivers. Invasive populations of both species show considerable genetic diversity and structure (zebra
F
ST = 0.006–0.263, quagga F
ST = 0.008–0.267), without founder effects. Most newer zebra mussel populations have appreciable genetic diversity, whereas
quagga mussel populations from the Colorado River and California show some founder effects. The population genetic composition
of both species changed over time at given sites; with some adding alleles from adjacent populations, some losing them, and
all retaining closest similarity to their original composition. Zebra mussels from Kansas and California appear genetically
similar and assign to a possible origin from the St. Lawrence River, whereas quagga mussels from Nevada and California assign
to a possible origin from Lake Ontario. These assignments suggest that overland colonization pathways via recreational boats
do not necessarily reflect the most proximate connections. In conclusion, our microsatellite results comprise a valuable baseline
for resolving present and future dreissenid mussel invasion pathways. 相似文献
5.
Charles R. Warren Ismael Aranda F. Javier Cano 《Metabolomics : Official journal of the Metabolomic Society》2012,8(2):186-200
Past studies of water stress in Eucalyptus spp. generally highlighted the role of fewer than five “important” metabolites, whereas recent metabolomic studies on other
genera have shown tens of compounds are affected. There are currently no metabolite profiling data for responses of stress-tolerant
species to water stress. We used GC–MS metabolite profiling to examine the response of leaf metabolites to a long (2 month)
and severe (Ψpredawn < −2 MPa) water stress in two species of the perennial tree genus Eucalyptus (the mesic Eucalyptus pauciflora and the semi-arid Eucalyptus dumosa). Polar metabolites in leaves were analysed by GC–MS and inorganic ions by capillary electrophoresis. Pressure–volume curves
and metabolite measurements showed that water stress led to more negative osmotic potential and increased total osmotically
active solutes in leaves of both species. Water stress affected around 30–40% of measured metabolites in E. dumosa and 10–15% in E. pauciflora. There were many metabolites that were affected in E. dumosa but not E. pauciflora, and some that had opposite responses in the two species. For example, in E. dumosa there were increases in five acyclic sugar alcohols and four low-abundance carbohydrates that were unaffected by water stress
in E. pauciflora. Re-watering increased osmotic potential and decreased total osmotically active solutes in E. pauciflora, whereas in E. dumosa re-watering led to further decreases in osmotic potential and increases in total osmotically active solutes. This experiment
has added several extra dimensions to previous targeted analyses of water stress responses in Eucalyptus, and highlights that even species that are closely related (e.g. congeners) may respond differently to water stress and re-watering. 相似文献
6.
Species diversity, abundance, and vertical size structure of rattans in Borneo and Java 总被引:1,自引:0,他引:1
We studied rattan communities in four forest types in Borneo and Java to clarify the pattern of species diversity and vegetation
structure. Within six plots of 4.82 ha in total, we found 42 rattan species in six genera with 4,736 stems (≥20 cm long).
There was a significant positive correlation between rattans and trees in species diversity, decreasing in the order mixed
dipterocarp (for rattans: Shannon–Wiener diversity index, H′ = 2.87–3.34) > alluvial (1.96) > lower montane (1.43) > peat swamp forests (1.34). This pattern coincided with the diversity
of the regional flora. The density of rattan stems (ha–1) decreased in the order lower montane (5,997) > mixed dipterocarp (598–992) > alluvial (592) > peat swamp forests (162).
The maximum height of rattans would be determined by the canopy height, rather than by the maximum tree height. The rattan
stem volume ranged from 0.25 to 1.88 m3 ha−1 and was not correlated with the stem density. The cool montane climate seemed to decrease the maximum height of rattans,
and a few small rattans made denser colonies. Swampy environments apparently suppressed the survival of non-climbing rattans
strongly, but that of tall climbing rattans less so. 相似文献
7.
Barbara L. Langille Josephine Hyde Kathleen M. Saint Tessa M. Bradford Danielle N. Stringer Simon M. Tierney William F. Humphreys Andrew D. Austin Steven J. B. Cooper 《Evolution; international journal of organic evolution》2021,75(1):166-175
Most subterranean animals are assumed to have evolved from surface ancestors following colonization of a cave system; however, very few studies have raised the possibility of “subterranean speciation” in underground habitats (i.e., obligate cave‐dwelling organisms [troglobionts] descended from troglobiotic ancestors). Numerous endemic subterranean diving beetle species from spatially discrete calcrete aquifers in Western Australia (stygobionts) have evolved independently from surface ancestors; however, several cases of sympatric sister species raise the possibility of subterranean speciation. We tested this hypothesis using vision (phototransduction) genes that are evolving under neutral processes in subterranean species and purifying selection in surface species. Using sequence data from 32 subterranean and five surface species in the genus Paroster (Dytiscidae), we identified deleterious mutations in long wavelength opsin (lwop), arrestin 1 (arr1), and arrestin 2 (arr2) shared by a sympatric sister‐species triplet, arr1 shared by a sympatric sister‐species pair, and lwop and arr2 shared among closely related species in adjacent calcrete aquifers. In all cases, a common ancestor possessed the function‐altering mutations, implying they were already adapted to aphotic environments. Our study represents one of the first confirmed cases of subterranean speciation in cave insects. The assessment of genes undergoing pseudogenization provides a novel way of testing modes of speciation and the history of diversification in blind cave animals. 相似文献
8.
Anton Brancelj 《Hydrobiologia》2009,621(1):85-104
The unsaturated zone in fissured (= karstic) aquifers continues to be a source of new species of Harpacticoida (Crustacea:
Copepoda). The first species were discovered about 70 years ago in the Škocjanske Jame Cave in Slovenia. Intensive sampling
of percolating water in caves there over the last 20 years has yielded several new species, some of them well adapted to that
environment. The most recent studies revealed that such a specialised fauna is also present in other regions of Europe, South
and North America, and Asia. In Europe, three genera belonging to the order Harpacticoida are characteristic of the unsaturated
karstic zone: Morariopsis, Paramorariopsis and Elaphoidella. In this article, two highly specialised species of Elaphoidella are described. A detailed analysis of their ecology and morphological adaptations along with other species of the genus Elaphoidella from Slovenia is included, and comparisons are made with the epikarstic genera Morariopsis and Paramorariopsis.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Handling editor: S. I. Dodson 相似文献
9.
Abstract: Bolbozoid and cypridinid myodocope ostracods from France, the Czech Republic and Sardinia consist of four genera (one new: Silurocypridina) and at least ten species (eight new: Bolbozoe acuta, B. rugosa, B. parvafraga, Parabolbozoe armoricana, Silurocypridina retroreticulata, S. variostriata, S. calva and Calocaria robusta). They have a functional design, palaeogeographical distribution, depositional setting and faunal associates that suggest that they were swimmers in the water column, living in dim light, relatively deep environments, above near bottom dysoxic/anoxic conditions. These myodocope faunas include some possible pelagic species sensu stricto, with widespread palaeogeographical (transoceanic) distribution, and some species that occupied hyperbenthic niches and were capable of making short incursions to the sediment to scavenge on carrion. These data support the model that Silurian myodocopes were pioneer pelagic ostracods. 相似文献
10.
A new species of Hirsutella, H. proturicola, isolated from a subterranean proturan (Baculentulus densus; Protura, Hexapoda), is described and illustrated. Hirsutella proturicola is characterized by producing monoblastic phialides of 24–51.5 × 2.5–5 μm with a slightly roughened neck, fusiform and curved
conidia of 9–18 × 2.5–4 μm that have a truncate base and a papillate projection often capped with sheath-like mucilage, and
pluricellular, globose to subglobose chlamydospores of 21–48 × 21–41.5 μm. This species is morphologically and phylogenetically
close to H. rostrata, an acaropathogenic species, but can be distinguished from the size of the phialides and the size and shape of the conidia. 相似文献
11.
Water sources accessed by arid zone riparian trees in highly saline environments,Australia 总被引:2,自引:0,他引:2
Johnson DW 《Oecologia》2008,155(1):43-52
The flow regimes of arid zone rivers are often highly variable, and shallow groundwater in the alluvial aquifers can be very
saline, thus constraining the availability and quality of the major water sources available to riparian trees—soil water,
shallow groundwater and stream water. We have identified water sources and strategies used by riparian trees in more highly
saline and arid conditions than previously studied for riparian trees of arid zone rivers. Our research focused on the riparian
species Eucalyptus coolabah, one of the major riparian trees of ephemeral arid zone rivers in Australia. The water sources available to this riparian
tree were examined using δ18O isotope data from xylem, soil water, groundwater and surface water. Additionally, soil chloride and matric potential data
were used to infer zones of water availability for root uptake. Despite the saline conditions, the trees used a mixture of
soil water and groundwater sources, but they did not use surface water directly. The study identified three strategies used
to cope with typically high groundwater and soil water salinities. Firstly, the trees preferentially grow in zones of most
frequent flushing by infiltrating streamflow, such as the bank-tops of channels. Secondly, the trees limit water use by having
low transpiration rates. Thirdly, the trees are able to extract water at very low osmotic potentials, with water uptake continuing
at chloride concentrations of at least 20,000–30,000 mg L−1. 相似文献
12.
Reinhard Agerer 《Mycological Progress》2002,1(2):225-228
Several scientists collected extensively cyphellaceous Hymenomycetes, Basidiomycota, with cup-shaped fruitbodies for the ‘Flora
Neotropica’ project. A distinctive group within these fungi comprises genera with characteristically encrusted, non-ramified
hyphae on the outer side of their fruitbodies, called surface hyphae. The genus Flagelloscypha, typically provided with whiplash-like distal ends on these hyphae, is one of the better known genera of this group. Here,
we propose F. crassipilata as a new species, which is characterised by (3.5)4–6.5(8) μm thick surface hyphae, by extremely big basidia measuring 36–40(44) × 8.5–10.5 μm, and asymmetrically ovoid to asymmetrically ellipsoid, 10.5–12 × (4.5)5–5.5 μm large spores. Differences to similar species are discussed and a short introduction to genera related to Flagelloscypha is given. 相似文献
13.
Atkinson T Cairns S Cowan DA Danson MJ Hough DW Johnson DB Norris PR Raven N Robinson C Robson R Sharp RJ 《Extremophiles : life under extreme conditions》2000,4(5):305-313
In March 1996, a survey of hydrothermal sites on the island of Montserrat was carried out. Six sites (Galway's Soufrière,
Gages Upper and Lower Soufrières, Hot Water Pond, Hot River, and Tar River Soufrière) were mapped and sampled for chemical,
ATP, and microbial analyses. The hydrothermal Soufrière sites on the slopes of the active Chances Peak volcano exhibited temperatures
up to almost 100°C and were generally either mildly acidic at pH 5–7 or strongly acidic at pH 1.5–3, but with some hot streams
and pools of low redox potential at pH 7–8. Hot Water Pond sites, comprising a series of heated pools near the western shoreline
of the island, were neutral and saline, consistent with subsurface heating of entrained seawater. Biological activity shown
by ATP analyses was greatest in near-neutral pH samples and generally decreased as acidity increased. A variety of heterotrophic
and chemolithotrophic thermophilic organisms were isolated or observed in enrichment cultures. Most of the bacteria that were
obtained in pure culture were familiar acidophiles and neutrophiles, but novel, iron-oxidizing species of Sulfobacillus were revealed. These species included the first mesophilic iron-oxidizing Sulfobacillus strains to be isolated and a strain with a higher maximum growth temperature (65°C) than the previously described moderately
thermophilic Sulfobacillus species.
Received: March 19, 2000 / Accepted: August 2, 2000 相似文献
14.
Experimental sites were established at two locations in north-eastern Victoria to define factors limiting the establishment
and growth of Trifolium subterranean L. (subterranean clover). Liming the soil, seed inoculation and fungicide application were used in renovating subterranean
clover pasture on two acidic soils (Longwood: brown/grey sandy loam DY 3.14 and Seymour: grey brown light clay DY 3.22, Northcote
classification) with mean annual rainfall of 650 mm and 600 mm respectively.
Soil acidity, low available soil phosphorus and plant disease were identified as factors limiting clover yield on these soils.
Significant yield responses to lime (35–140%) were obtained with subterranean clover at both sites, with corresponding decreases
in Al in the 0–10 cm soil horizon. Liming the soil, when combined with seed inoculation, increased the number and effectiveness
of root nodules at both sites. Soil P available for plant growth was low at both sites (6.1 and 8.4 μg g−1) resulting in sub-optimal P concentrations in the clover herbage (45 mmol kg−1 at Longwood). Levels of root disease were low but Aphanomyces euteiches and Phytophthora clandestina (causal agents of lateral and tap root rot) were detected frequently on roots. Application of fungicide resulted in higher
dry matter yields (p=0.05) at both sites.
An assessment of the relative contributions of these limiting factors and the benefits to be obtained from better management
would provide a clearer picture of the profitability and sustainability of this farming system. 相似文献
15.
Molecular analysis of spatial variation of iron-reducing bacteria in riverine alluvial aquifers of the Mankyeong River 总被引:1,自引:0,他引:1
Kim SJ Koh DC Park SJ Cha IT Park JW Na JH Roh Y Ko KS Kim K Rhee SK 《Journal of microbiology (Seoul, Korea)》2012,50(2):207-217
Alluvial aquifers are one of the mainwater resources in many countries. Iron reduction in alluvial aquifers is often a major
anaerobic process involved in bioremediation or causing problems, including the release of As trapped in Fe(III) oxide. We
investigated the distribution of potential iron-reducing bacteria (IRB) in riverine alluvial aquifers (B1, B3, and B6 sites)
at the Mankyeong River, Republic of Korea. Inactive iron reduction zones, the diversity and abundance of IRB can be examined
using a clone library and quantitative PCR analysis of 16S rRNA genes. Geobacter spp. are potential IRB in the iron-reducing zone at the B6 (9 m) site, where high Fe(II) and arsenic (As) concentrations
were observed. At the B3 (16 m) site, where low iron reduction activity was predicted, a dominant clone (10.6%) was 99% identical
in 16S rRNA gene sequence with Rhodoferax ferrireducens. Although a major clone belonging to Clostridium spp. was found, possible IRB candidates could not be unambiguously determined at the B1 (18 m) site. Acanonical correspondence
analysis demonstrated that, among potential IRB, only the Geobacteraceae were well correlated with Fe(II) and As concentrations. Our results indicate high environmental heterogeneity, and thus high
spatial variability, in thedistribution of potential IRB in the riverine alluvial aquifersnear the Mankyeong River. 相似文献
16.
Different precipitation regimes across Patagonia generate an environmental gradient that is expected to reflect upon the solute composition and concentration of lake water through the ensuing differences in water balance. In turn, this hydrochemical gradient could influence the occurrence and distribution of ostracods in the area. A cluster analysis on hydrochemical data of 36 Southern Patagonian waterbodies shows that low salinity, bicarbonate-dominated waters characterize Andean and ecotonal lakes, located in the wetter part of the precipitation gradient, while their steppe counterparts, which receive a much lower precipitation input, are more saline, enriched in all major anions and sodium-dominated. Kruskal–Wallis tests followed by Mann–Whitney pairwise comparisons show statistically significant differences in the ostracod species each water type hosts, with L. patagonica, E. cecryphalium, P. smaragdina and P. incae being found in the more dilute waters characteristic of Andean and ecotonal lakes and Limnocythere rionegroensis in the mesohaline, evaporatively evolved waters typical of steppe lakes. Other species studied do not appear to have such distinct distributions, having been found throughout the range of conditions studied. These findings promote the use of the aforementioned ostracods as semi-quantitative paleohydrological indicators, which could improve paleoclimatic reconstructions in Patagonia. 相似文献
17.
18.
Tsuyoshi Hosoya Rei Sasagawa Kentaro Hosaka Sung Gi-Ho Yumiko Hirayama Kaoru Yamaguchi Kyoko Toyama Makoto Kakishima 《Mycoscience》2010,51(3):170-181
Molecular phylogenetic studies were carried out based on ITS-5.8S rDNA, the D1–D2 region of the large subunit rRNA gene, RPB2,
and combined data of D1–D2 and RPB2 as well as these three genes on 36 species among 7 genera for Lachnum and allied genera in the family Hyaloscyphaceae. In the combined data of all three regions, seven strongly supported clades
were obtained. The same clades were also recognized in most of the trees based on each gene, and the combined data of D1–D2
and RPB2, although some of them were not strongly supported. Four clades represented Albotricha, Brunnipila, Incrucipulum, and Lachnellula, respectively, whereas Lachnum was distributed to the remaining three clades. The molecular phylogenies strongly supported a group of species with granulate
hairs, and we suggest the concept of Lachnaceae should be restricted to these species. Based on the molecular phylogenetic
analysis, three new combinations—Incrucipulum longispineum, I. radiatum, and Lachnellula pulverulentum from Lachnum—are proposed. 相似文献
19.
The species richness of putative ectomycorrhizal (EM) fungi fruiting in blue gum (Eucalyptus globulus Labill.) plantations in Western Australia was investigated in relation to plantation age. Eleven plantations, 1–8 years old,
were selected for study and two native Eucalyptus forest sites in the same region were chosen for comparison. Sporocarps of 44 species of putative EM fungi were collected from
the 13 sites. Of these, 30 species were found in blue gum plantations. The number of fungal species was highly positively
correlated with plantation age and inversely correlated with soil pH. Young plantations (1–5 years) had 2–9 fungal species
and were overwhelmingly dominated by species of Laccaria and Scleroderma. In older plantations (6–8 years), the relative abundance of sporocarps of each species within the fungal community decreased,
accompanied by an increase in the number of fungal species (12–17 per site). A brief survey of the two native eucalypt forests
in this region revealed a much higher number of fungal species than that observed in plantations. In plantations, species
of Descolea, Laccaria, Pisolithus and Scleroderma typically fruited in young plantations. Species of epigeous fungi of the genera Boletus, Cortinarius, Hydnum, Inocybe, Lactarius, Paxillus, Russula and hypogeous fungi, including species of Descomyces, Hysterangium and Mesophellia, were found only in older plantations, or in native forests. Some of the fungi that fruit in young plantations are now being
evaluated for use in commercial spore inoculation programs to increase the species diversity of EM fungi in exotic eucalypt
plantations.
Accepted: 8 October 1998 相似文献
20.
The most-probable-number enumeration of dichlobenil and 2,6-dichlorobenzamide (BAM) degrading microbes in Finnish aquifers 总被引:2,自引:0,他引:2
Veera Pukkila Juhani Gustafsson Jari Tuominen Anri Aallonen Merja H. Kontro 《Biodegradation》2009,20(5):679-686
In groundwater subsurface deposits and a topsoil from five aquifers having 2,6-dichlorobenzamide (BAM) in water, we determined
the most-probable-number (MPN) of 2,6-dichlorobenzonitrile (dichlobenil) and metabolite BAM degrading microorganisms. Dichlobenil
and BAM were combined nitrogen sources in the MPN tubes, which were scored positive at concentrations <75% after 1 month incubation.
Aerobic and anaerobic microbes degrading dichlobenil and BAM were common in samples in low numbers of 3.6–210 MPN g dw−1. Additional degradation occurred in high MPN dilutions of some samples, the microbial numbers being 0.11–120 × 105 MPN g dw−1. The strains were isolated from low and high dilutions of one deposit, and degradation in pure cultures was confirmed by
HPLC. According to the 16S rDNA sequencing, strains were from genera Zoogloea, Pseudomonas, Xanthomonas, Rhodococcus, Nocardioides, Sphingomonas, and Ralstonia. Dichlobenil (45.5 ± 18.3%) and BAM (37.6 ± 14%) degradation was low in the MPN tubes. Despite of microbial BAM degradation
activity in subsurface deposits, BAM was measured from groundwater. 相似文献