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Fivenew species of the genus Triotemnus from Morocco and Yemen are described. Triotemnus is a new genus of Scolytinae for the Yemen region. External morphology of the new species and all morphologically related species of the genus were studied. While the new species from Morocco are morphologically similar to the known species from the corresponding region, all three newly described species from Yemen, mainly two of them living in Socotra, are morphologically very different from all other known species of the genus. Geographical distribution and the probability of endemicity are discussed. 相似文献
3.
Unique Dracaena cinnabari woodlands on Socotra Island—relics of the Mio-Pliocene xerophile-sclerophyllous southern Tethys Flora—were examined in detail, especially with regard to their age structure. Detailed statistical analyses of sets of 50 trees at four localities were performed in order to define a model reflecting relationships between specific growth habit and actual age. The problematic nature of determining the age of an individual tree or specific populations of D. cinnabari is illustrated by three models relating to orders of branching, frequency of fruiting, etc. which allow the actual tree age to be calculated. Based on statistical analyses as well as direct field observations, D. cinnabari populations on Socotra do not regenerate to a great extent and their age structure generally indicates overmaturity. The unique Firmihin D. cinnabari woodland will reach the stage of intensive disintegration within 30–77 years with 95% probability. According to our analysis of dead trees, it is evident that, on average, D. cinnabari in populations at Firmihin dies after reaching 17 orders of peripheral branches. 相似文献
4.
《Saudi Journal of Biological Sciences》2017,24(5):1094-1103
Propolis is a gummy material made by honeybees for protecting their hives from bacteria and fungi. The main objective of this study is to determine the chemical compositions and concentrations of organic compounds in the extractable organic matter (EOM) of propolis samples collected from four different regions in Yemen. The propolis samples were extracted with a mixture of dichloromethane and methanol and analyzed by gas chromatography–mass spectrometry (GC–MS). The results showed that the total extract yields ranged from 34% to 67% (mean = 55.5 ± 12.4%). The major compounds were triterpenoids (254 ± 188 mg g−1, mainly α-, β-amyryl and dammaradienyl acetates), n-alkenes (145 ± 89 mg g−1), n-alkanes (65 ± 29 mg g−1), n-alkanoic acids (40 ± 26 mg g−1), long chain wax esters (38 ± 25 mg g−1), n-alkanols (8 ± 3 mg g−1) and methyl n-alkanoates (6 ± 4 mg g−1). The variation in the propolis chemical compositions is apparently related to the different plant sources. The compounds of these propolis samples indicate that they are potential sources of natural bio-active compounds for biological and pharmacological applications. 相似文献
5.
Evolutionary trends in Late Permian Darwinulocopina are summarised with reference to extensive collections from eastern European Russia, from the White Sea in the North to the Cis-Caspian in the South. They inhabited large, shallow lakes in which the variety of habitats was favourable for high ostracod diversity. Three superfamilies are represented: the Darwinuloidea preferred lakes with terrigenous sedimentation and insignificant bicarbonate, the Suchonelloidea inhabited lakes with increased bicarbonate and could also live in low-sulphate waters, and the Darwinuloidoidea inhabited high-bicarbonate water bodies and could also survive in low-magnesium waters. Different evolutionary trends account for the different ages of the crucial stages of development of each superfamily: the beginning of the mid-Tatarian for the Darwinuloidea, the late Tatarian for the Suchonelloidea and Darwinuloidoidea. 相似文献
6.
Syed G. Dastager Ashok Pandey Jae-Chan Lee Wen-Jun Li Chang-Jin Kim 《Current microbiology》2009,59(1):21-29
Aerobic, alkaliphilic to alkalitolerant and mesophilic bacteria were isolated and characterized from soil and sediment samples collected from Bigeum Island, South Korea. The total numbers of microorganisms in the soil and sediment samples were found to be 103–105 cfu/g and 102–107 cfu/g, respectively. A total of 163 isolates were isolated and subjected to further characterization on the basis of pH, temperature and salt tolerance. Among the 163 isolates, 54 were selected based on their tolerance attributes to temperature, pH and NaCl. Out of the 54 isolates, 27 were further selected based on their multiple tolerance ability and enzyme profile and were subjected to 16S rRNA gene sequencing and phylogenetic analysis. The latter indicated that most of the Bigeum Island isolates were related to the phylum Actinobacteria. The phylogenetic tree based on 16S rRNA gene sequences placed the 27 isolates into 9 different major bacterial genera, each genus comprising pure cultures that shared ≤97% sequence identity and 18 putative novel species. Most of the strains were alkalitolerant and mesophilic, and produced biotechnologically important enzymes at alkaline pH. 相似文献
7.
Freshwater ecology: changes, requirements, and future demands 总被引:5,自引:0,他引:5
R. G. Wetzel 《Limnology》2000,1(1):3-9
The past development and evolution of limnology as a discipline has demonstrated that experimentally controlled disturbances
of parts of aquatic ecosystems are essential for quantitative evaluation of causal mechanisms governing their operation. Correlative
analyses and modeling only establish hypotheses, not causality, and allow only therapeutic management applications. Rather
than constantly searching for differences, commonality must be sought. Among the large diversity of species, communities,
and biogeochemical processes controlling growth and reproduction, commonality emerges at the levels of regulation of metabolism.
Five areas of current and future limnological research are discussed in relation to greatest needs and promise to yield insights
into material and energy flows in freshwater ecosystems and their effective management: (1) coupled metabolic mutualism in
the physiological ecology of microbes (viruses, bacteria, fungi, and protists) and their biogeochemical, especially organic,
couplings with the environment; (2) biochemical regulation of collective metabolism, recycling, and bioavailability of nutrients
and growth regulators; (3) application of genetic and molecular techniques to addressing biogeochemical, evolutionary, and
pollution remediation problems; (4) recognition that the metabolism within lakes and streams is dependent upon and regulated
to a major extent by organic matter of the drainage basin and especially by the land-water interface biogeochemistry; and
(5) recognition that food-web alterations ("biomanipulation") are short-term, expensive therapeutic tools that may minimize
effects of eutrophication but will not solve or control eutrophication.
Received: October 30, 1999 / Accepted: December 6, 1999 相似文献
8.
A new method for temperature compensation of electrical conductivity (EC) is proposed. A relationship between temperature and EC was investigated in detail by a simple experiment using natural and artificial fresh water. Results showed that the temperature dependency of EC varied from 0.03 to 0.02, with temperature increasing from 3°C to 35°C. This means that a traditional method for compensating for EC using a constant coefficient is invalid, so that a temperature-fold dependency must be taken into consideration to standardize EC to a common temperature. 相似文献
9.
Fresh water on a small marine island is rather limited and could be the habitat of aquatic fungi. Members of the Saprolegniales and Peronosporales can survive on organic matter found floating or submerged in shallow water. Recently a preliminary study was conducted on the keratinophilic fungi of Abaco Island, The Bahamas (5). The same island was surveyed for fresh water fungi in this investigation. 相似文献
10.
Spatiotemporal distribution of nocturnal coral reef fish juveniles in Moorea Island,French Polynesia
This study aimed to investigate the spatial structure of nocturnal fish communities at settlement on coral reefs in Moorea
Island lagoon, French Polynesia; and the temporal consistency of habitat selection between winter (April to June 2001) and
summer (November 2001). The Moorea lagoon was divided into 12 habitat zones (i.e., coral reef zones), which were distinct
in terms of depth, wave exposure, and substratum composition. Nocturnal visual censuses among the 12 habitats found that the
recently settled juveniles of 25 species recorded were dispatched among three communities spatially distributed according
to the distance from the reef crest (reef crest, barrier reef, and fringing reef communities). This spatial communities structure
of nocturnal juveniles was consistent in both winter and summer and would be explained primarily by a current gradient in
Moorea lagoon (current speed was high near the reef crest and decreased towards the beach) and by the topographic characteristics
of reef zones. Among the 25 species, 13 were recorded in both winter and summer. A comparison of the spatial distribution
between summer and winter for 13 species that occurred during both seasons found that only 4 differed between the two seasons.
For these species, habitat selection would be organized primarily by some stochastic processes such as inter- and intraspecific
competition, predation, and food availability. Overall, the present study allowed us to highlight that most nocturnal coral
reef fish juveniles at Moorea Island exhibited striking patterns in their distribution and current and topographic characteristics
of reef zones might exert considerable influence on the distribution of fishes. 相似文献
11.
The genus Semicytherura belongs to the family Cytheruridae, and was distinguished from Cytherura on the basis of carapace features. Species of Semicytherura from Japan and adjacent seas can be divided into two groups. One is represented by Semicytherura miurensis Hanai, 1957, characterized by a thin, oval carapace covered with fine reticulation. The other is represented by Semicytherura henryhowei Hanai & Ikeya, 1977, characterized by a thick sub-rectangular carapace in lateral view. Semicytherura henryhowei, which is distributed from Hokkaido to Okinawa in Japan, has been regarded as having several morphotypes distinguishable
on outline and reticulation of carapace. However, as a result of detailed observations on the copulatory organ, carapace outline
and distributional pattern of pore systems, remarkable differences are shown to exist between the two most frequently occurring
morphotypes. In order to recognize S. henryhowei sensu stricto, the carapace of the holotype was re-examined. Consequently, neither of the two morphotypes are considered to belong to S. henryhowei due to differences of carapace outline and distribution of pore systems. The two morphotypes are here regarded as independent
taxa, described as new: S. kazahanan. sp. and S. sasameyukin. sp. The geographical distributions of the two new species overlap, but their micro-habitats differ from each other; the
former lives on calcareous algae on rocky shores, the latter lives on silty sand bottom within the inner bay. A third new
species, S. slipperi sp. nov., is also described. In view of their present geographical distributions and fossil records, the origin of this group
of species would appear to be the Japanese islands or adjacent areas in and after the Miocene. This group then migrated to
the Arctic Ocean and East Pacific Ocean during or before the middle Pliocene. 相似文献
12.
We studied the monkeys inhabiting Bacan Island on the Maluku Archipelago, Indonesia. We compared them morphologically with
Sulawesi black macaques (Macaca nigra).We also assessed their distribution on the island and on neighboring islands and the influence of human activity on them.
We found that the Bacan black macaques are essentially similar to Sulawesi macaques; the variations in each locality are comparable.
The monkeys probably inhabit the whole island or, at least, the lower forest thereon. Human activities — cultivation, logging,
catching and killing monkeys — have not much affected their population. Thus they constitute a good stock of Macaca nigra,though the main population in Sulawesi is endangered. 相似文献
13.
Edmundo C. Drago 《Hydrobiologia》1989,184(1-2):51-60
During January and February 1981, water temperature measurements were made in lakes and ponds of Deception Island, Antarctica. The depth of these waterbodies varies between 0.88 m and 36 m, with maximum surface areas of over 290 000 m2. Some ponds freeze completely during winter, and the lakes are covered by ice for 9–10 months of each year. The maximum ice thickness measured in early summer (December), dit not exceed 0.5 m. Solar radiation and geothermal heating largely determine the thermal structure of these aquatic environments. The water temperature of tributary meltwater streams did not exceed 3 °C, but the littoral waters reached 9 °C. The bottom water temperatures of meromictic lakes 5 (Irízar) and 9, are 12.3 °C and 19.9 °C respectively. These deep waters are heated from geothermal sources and it is possible that some ponds may be also influenced by their proximity to hot soils. With the exception of the meromictic lakes, the aquatic environments studied here did not show a vertical stratification of temperature. It is not possible to establish a general thermal classification for the waterbodies of Deception Island. The interaction of the lacustrine morphology, solar radiation and vulcanism produce contrasting thermal features. Taking into account only the upper layers of meromictic lakes (mixolimnion), and emphasizing the fact of that some ponds freeze completely during winter, the waterbodies of Deception Island would be classified as ‘pleomictics’ (Paschaslki, 1964). This work was supported by an agreement between the Instituto Antártico Argentino and the Instituto Nacional de Limnología (Programa Limnoantar). This work was supported by an agreement between the Instituto Antártico Argentino and the Instituto Nacional de Limnología (Programa Limnoantar). 相似文献
14.
A large bipedal tridactyl dinosaur trackway from the Late Jurassic of Serwah, near Madar, Arhab district, Republic of Yemen, has been attributed to an ornithopod trackmaker. As the distinction between theropod and ornithopod dinosaurs can pose a challenge, we present additional data to support and reconfirm the previous attribution. 相似文献
15.
Madha Mohammed Sheet Saleh Adam Hezam AL-Shamiri Abeer Ahmed Qaed 《The Korean journal of parasitology》2010,48(1):71-73
This cross sectional study was conducted in the city of Taiz, Yemen, during the period from August 2006 to August 2007 in order to investigate the seroprevalence and incidence of toxoplasmosis among apparently healthy children (AHC) and visually and/or hearing disabled children (DC). The seroprevalence was 16.0% among AHC compared to 32.5% among DC. The effect of gender was clear as the seroprevalence rate was significantly higher among females (18.3 and 43.8% for AHC and DC, respectively) than males (13.8 and 25% for AHC and DC, respectively). The seroprevalence was proportionally increased with the age, and the highest rates (20.9 and 53.0%) were reported among the oldest age group (> 10-14 years) for AHC and DC groups, respectively. The incidence rate was also higher (4.2%) in DC group compared to AHC group (2.4%) during 1 year period. These data indicate that the seroprevalence and incidence of toxoplasmosis are significantly higher in DC group than those of AHC group. We need to check further relationship between toxoplasmosis and visual and/or hearing disability. 相似文献
16.
The ecology of ostracods in the northern Japan Sea is well documented. These ostracods can be grouped in two assemblages: (1) the Tsushima Warm Current Surface Water Assemblage (TWSA, northern), which lives in an environment where summer temperatures reach up to about 20 °C, winter temperatures up to about 5 °C. Several species in this assemblage, e.g., Loxoconcha optima and Pontocythere subjaponica tolerate seasonally low temperatures, and lived in the region since the early Pleistocene; (2) the Japan Sea Intermediate Proper Water Assemblage (JSI-PA), which lives at greater depths (lower shelf to upper slope). This assemblage lives under stable conditions, with a small annual range in temperature (0–5 °C). The assemblage has a relatively low diversity, contains species such as Acanthocythereis dunelmensis and Robertsonites spp., and has been present in the area since the Pliocene. These data indicate that the presently living species either tolerate seasonally low temperatures (TWSA, northern) or tolerate stable, but very low temperatures (near 0 °C), and therefore, they could survive the Pleistocene environmental fluctuations in the Japan Sea caused by glacio-eustatic changes in sea level. Our data document the survival of ostracod species during past climate change, and thus can be used to speculate on the effect of possible future climate change on the faunas. We predict that some of the cryophilic species in the Japan Sea cannot be expected to survive global warming for more than 2 centuries. 相似文献
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18.
The East Mediterranean species of Orthomus Chaudoir, 1838 are revised. The type series of Feronia longula Reiche & Saulcy, 1855, F. berytensis Reiche & Saulcy, 1855, F. proelonga Reiche & Saulcy, 1855, Orthomus longior Chaudoir, 1873, O. sidonicus Chaudoir, 1873, and O. berytensis akbensis Mateu, 1955 were studied and lectotypes for the first four are designated. Also, the following nomenclatural acts are proposed: Feronia proelonga Reiche & Saulcy, 1855, syn. n. of Orthomus berytensis (Reiche & Saulcy, 1855); Feronia elongata Chaudoir, 1859, syn. n. of Orthomus berytensis (Reiche & Saulcy, 1855); Orthomus sidonicus Chaudoir, 1873, syn. n. of Orthomus longior Chaudoir, 1873; Orthomus velocissimus andalusiacus Mateu, 1957, syn. n. of Orthomus velocissimus akbensis Mateu, 1955, new assignment for Orthomus berytensis akbensis Mateu, 1955. As a result, three species of the genus inhabit the East Mediterranean biogeographical region: O. berytensis, O. longior, and O. longulus. A key to these three species is given. O. longior is recorded for Turkey and Syria for the first time. In addition, a new synonymy of two West Mediterranean taxa is proposed: O. szekessyi (Jedlička, 1956), syn. n. of O. balearicus (Piochard de la Brûlerie, 1868), and a new genus and a species are described: Parorthomus
gen. n.
socotranus
sp. n. (type locality: Republic of Yemen, Socotra Archipelago, Socotra Island, Fimihin env., 530 m.a.s.l.). Illustrations of the species dealt with here are provided including external characters, habitus, mentum and submentum, and genitalia are provided.Nine genera of the “African Series” of subtribe Euchroina Chaudoir, 1874 are keyed for the first time. Checklists of the species of Orthomus and of the Old World euchroine genera are given. 相似文献
19.
Effects of edaphic factors (salinity, pH, Na+, K+, Ca++, CaCO3, water holding capacity, and grain size) on the spatial distribution of plants were investigated. Soil was sampled at 22 stands. Sixteen plant species were recorded from these stands. Relation between edaphic factors and plant distribution was investigated using correlation statistical analysis. Distribution of some plants was found to be highly correlated with edaphic factor(s). 相似文献
20.
P. T. Green 《Journal of Biogeography》1999,26(5):937-946
Aim To describe the species composition of stranded seeds and fruits drifted by ocean currents to Christmas Island, Indian Ocean. Location Christmas Island, Indian Ocean. Methods Frequent visual searches along the strand line of the island's few accessible beaches over a 4-year period 1988–92, with most effort concentrated on Greta Beach, on the east coast. Results The collection contained not fewer than sixty-three species in forty-nine genera and twenty-nine families. Leguminous seeds were by far the most common (especially Caesalpinia bonduc (L.) Roxb., Dioclea spp., Entada spp., Erythrina spp. and Mucunagigantea (Willd.) DC.), but Calophyllum inophyllum L., Guettarda speciosa L., Hernandia ovigera L., Heritiera littoralis Aiton and Terminalia catappa L. were also common. Main conclusions Only about one-third of species recorded in the drift flora are native to the island, and most disseminules stranded on the island are probably not locally derived. The most likely distant sources of drift disseminules are probably the southern Indonesian islands and Sumatra, with most disseminules probably arriving via the Timor and Arafura Seas between Indonesia and Australia. However, some disseminules may originate from as far east as the Moluccas and the east coast of Kalimantan. The majority of species recorded in the drift flora are not native to the island, and yet some of these were encountered frequently and displayed a high degree of viability on arrival (e.g. Dioclea hexandra (Ralph) Mabb., Erythrina fusca Loureiro and Mucuna gigantea (Willd.) DC.). Several possible reasons for the failure of many drift species to establish on the island are discussed. 相似文献