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1.
Parabiotic ants—ants that share their nest with another ant species—need to tolerate not only conspecific nestmates, but also
nestmates of a foreign species. The parabiotic ants Camponotus rufifemur and Crematogaster modiglianii display high interspecific tolerance, which exceeds their respective partner colony and extends to alien colonies of the
partner species. The tolerance appears to be related to unusual cuticular substances in both species. Both species possess
hydrocarbons of unusually high chain lengths. In addition, Cr. modiglianii carries high quantities of hereto unknown compounds on its cuticle. These unusual features of the cuticular profiles may
affect nestmate recognition within both respective species as well. In the present study, we therefore examined inter-colony discrimination within the two parabiotic
species in relation to chemical differentiation. Cr. modiglianii was highly aggressive against workers from alien conspecific colonies in experimental confrontations. In spite of high inter-colony
variation in the unknown compounds, however, Cr. modiglianii failed to differentiate between intracolonial and allocolonial unknown compounds. Instead, the cuticular hydrocarbons functioned
as recognition cues despite low variation across colonies. Moreover, inter-colony aggression within Cr. modiglianii was significantly influenced by the presence of two methylbranched alkenes acquired from its Ca. rufifemur partner. Ca. rufifemur occurs in two varieties (‘red’ and ‘black’) with almost no overlap in their cuticular hydrocarbons. Workers of this species
showed low aggression against conspecifics from foreign colonies of the same variety, but attacked workers from the respective
other variety. The low inter-colony discrimination within a variety may be related to low chemical differentiation between
the colonies. Ca. rufifemur majors elicited significantly more inter-colony aggression than medium-sized workers. This may be explained by the density
of recognition cues: majors carried significantly higher quantities of cuticular hydrocarbons per body surface. 相似文献
2.
The role of the Orii’s flying-fox (Pteropus dasymallus inopinatus) as a pollinator and a seed disperser on Okinawa-jima Island was investigated by direct observations and radio-tracking from
October 2001 until January 2006. We found that Orii’s flying-fox potentially pollinated seven native plant species. Its feeding
behavior and plant morphological traits suggested that this species is an important pollinator of Schima wallichii liukiuensis and Mucuna macrocarpa. The flying-fox also dispersed the seeds of 20 native plant species. The seeds of all plants eaten by the flying-fox were
usually dropped beneath the parent tree, although large fruits of four plant species were occasionally brought to the feeding
roosts in the mouth, with the maximum dispersal distance—for Terminalia catappa—estimated to be 126 m. Small seeds of 11 species (mostly Ficus species) were dispersed around other trees, during the subsequent feeding session, through the digestive tracts, with the
mean dispersal distance for ingested seeds estimated at 150 ± 230.3 m (±SD); the maximum dispersal distance was 1833 m. A
comparison of the seed dispersal of available fruits according to the size of flying-foxes and other frugivores suggested
that the seed dispersal of eight plant species producing large fruits mostly depended on Orii’s flying-fox. On Okinawa-jima
Island, the Orii’s flying-fox plays an important role as a pollinator of two native plants and as a long-distance seed disperser
of Ficus species, and it functions as a limited agent of seed dispersal for plants producing large fruits on Okinawa-jima Island. 相似文献
3.
Changes in the abscisic acid (ABA) levels in embryo axes of seeds, belonging to the orthodox (Norway maple — Acer platanoides L.) and recalcitrant (sycamore — Acer pseudoplatanus L.) categories, were investigated throughout maturation using an ELISA (enzyme-linked immunosorbent assay) test. Concentration
of ABA in embryo axes substantially differed depending on species and sampling date. ABA was always higher in Norway maple
except at the end of seed maturation when ABA content was similar in both species. During maturation ABA decreased in both
species but the decline was more marked in Norway maple than in sycamore (11 vs. 3 fold). These species also differed in the pattern of ABA changes, which in sycamore embryo axes was very regular, while
in Norway maple a sharp decrease was recorded after acquisition by the seeds of tolerance to desiccation. Dehydration of embryo
axes of Norway maple caused a further significant decrease of ABA level. In contrast, in dehydrated sycamore embryo axes ABA
content did not decrease, but slightly increased. The role of ABA in desiccation tolerance and dormancy of Norway maple and
sycamore seeds is discussed. 相似文献
4.
Investigations of coevolutionary relationships between plants and the animals that disperse their seeds suggest that disperser-plant
interactions are likely shaped by diffuse, rather than species-to-species, coevolution. We studied the role of dietary plasticity
in shaping the potential for diffuse coevolution by comparing dietary fruit preferences and seed dispersal by 3 species of
spider monkeys (Ateles spp.) in 4 moist forests in Colombia, Ecuador, Panama, and Surinam. In all forests, spider monkeys were highly frugivorous
and preyed upon seeds of few species. We estimated dietary use of fruiting taxa based on absolute consumption and preference,
which accounts for resource availability. Of the 59 genera that comprised the 20 most frequently consumed genera summed in
each forest, only 3—Brosimum (Moraceae), Cecropia (Cecropiaceae) and Virola (Myristicaceae)—ranked within the top 20 at every forest. Most genera were within the 20 most frequently consumed at only
1 or 2 forests. Based on preferences, only 4 genera ranked in the 20 most-preferred in all 4 forests: Brosimum, Cecropia, Ficus (Moracae), and Virola. Patterns in fruit consumption and preference at the familial level were similar in that only 2 families—Myristicaceae and
Moraceae—were in the 10 most-consumed or most-preferred in all 4 forests. Interforest variation in plant specific composition
and abundances and supra-annual fruiting phenologies, combined with dietary flexibility of Ateles spp., may partly explain these patterns. Our results suggest that variation in plant community structure strongly influences
dietary preferences, and hence, seed dispersal by spider monkeys. Thus, diffuse coevolution in spider monkey-plant relationships
may be limited to few taxa at the generic and familial levels. 相似文献
5.
The sphingoid long-chain base (LCB) composition of glucosylceramides was characterized in 31 species of Fabaceae including
the model legumes Lotus japonicus and Medicago truncatula. With the exception of Lupinus texensis L, the 8-trans/cis-unsaturated isomers of 4-hydroxy-8-sphingenines [i.e., t18:1 (8t) plus t18:1 (8c)] were the major components in each species.
In tribe Fabeae, each species from four genera—Pisum, Lathyrus, Lens, and Vicia—showed that more than 50% of dihydroxy sphingoid LCBs are 8-sphingenines [i.e., d18:1 (8t) plus d18:1 (8c)]. These results
suggest that the sphingoid LCB composition of glucosylceramides reflects the phylogenetic relationships within the Fabeae. 相似文献
6.
Pelage color and pattern, facial markings, cranial morphology, and vocalization have been studied comparatively in thePresbytis melalophos group in Sumatera. Pelage coloration of fetuses and neonates were described forP. melalophos andP. femoralis. Based on this study, three species —P. thomasi, P. melalophos, andP. femoralis — are recognized. Using field data that have been gathered since 1981, the distribution of these three species has been mapped.
The resultant map reveals that no sympatry is known and that rivers form the interspecific boundaries. However, rivers apparently
are not barriers to the dispersal of species in this group. Instead, distributions appear to be limited ecologically, by competitive
exclusion. Historically, it appears that the ancestral stock initially dispersed throughout this area, then theP. melalophos stock split from theP. thomasi-P. femoralis stock, theP. thomasi stock split from theP. femoralis stock, and, finally, theP. femoralis stock dispersed to eastern Sumatera. It appears unlikely that the centrifugal speciation hypothesis based on the principle
of metachromism applies to deployment of theP. melalophos group. 相似文献
7.
Chloroplast DNA polymorphisms were analysed to infer the post-glacial history of Nothofagus nervosa (Phil.) Dim. et Mil., a species endemic to South American Temperate Forests. Two hypotheses were postulated to explain the current distribution of the species in relation to the refugia proposed after palynological studies and the time elapsed since Last Glacial Maximum. If refugia were located only in the Coastal Mountains, as pollen records suggests, long-distance dispersal events should be invoked to explain the current occurrence of the species in southern latitudes. The alternative hypothesis is the existence of cryptic refugia in southern latitudes. A total of 26 populations covering the entire geographical range of the species in Chile and Argentina were analysed through PCR–RFLP. Five haplotypes were identified, and a very low intrapopulation variation was observed together with a high gene differentiation (G
ST=0.93). The haplotypes showed a highly structured geographic distribution, separating populations located in the Pacific Coastal Mountains from those coming from the easterly located Andes Mountains. Moreover, among the populations of the Andes Mountains a north–south variation in the distribution of haplotypes was found. The results strongly suggest the persistence of the species in several ice-age refugia. The possible location of such refugia is discussed in combination with the available palynological data. 相似文献
8.
Josef Elster Peter Degma Ľubomír Kováčik Lucia Valentová Katarína Šramková Antonio Batista Pereira 《Biologia》2008,63(6):843-851
The freezing and desiccation tolerance of 12 Klebsormidium strains, isolated from various habitats (aeroterrestrial, terrestrial, and hydro-terrestrial) from distinct geographical
regions (Antarctic — South Shetlands, King George Island, Arctic — Ellesmere Island, Svalbard, Central Europe — Slovakia)
were studied. Each strain was exposed to several freezing (−4°C, −40°C, −196°C) and desiccation (+4°C and + 20°C) regimes,
simulating both natural and semi-natural freeze-thaw and desiccation cycles. The level of resistance (or the survival capacity)
was evaluated by chlorophyll a content, viability, and chlorophyll fluorescence evaluations. No statistical differences (Kruskal-Wallis tests) between strains
originating from different regions were observed. All strains tested were highly resistant to both freezing and desiccation
injuries. Freezing down to −196°C was the most harmful regime for all studied strains. Freezing at −4°C did not influence
the survival of studied strains. Further, freezing down to −40°C (at a speed of 4°C/min) was not fatal for most of the strains.
RDA analysis showed that certain Antarctic and Arctic strains did not survive desiccation at +4°C; however, freezing at −40°C,
as well as desiccation at +20°C was not fatal to them. On the other hand, other strains from the Antarctic, the Arctic, and
Central Europe (Slovakia) survived desiccation at temperatures of +4°C, and freezing down to −40°C. It appears that species
of Klebsormidium which occupy an environment where both seasonal and diurnal variations of water availability prevail, are well adapted to
freezing and desiccation injuries. Freezing and desiccation tolerance is not species-specific nor is the resilience only found
in polar strains as it is also a feature of temperate strains.
Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.
This paper is dedicated to the memory of the late Dr. Bohuslav Fott (1908–1976), Professor of Botany at the Charles University
in Prague, to mark the centenary of his birth. 相似文献
9.
Behavioural and physiological responses of infective juveniles of the entomopathogenic nematode Heterorhabditis to desiccation 总被引:1,自引:0,他引:1
Infective juveniles (IJs) of entomopathogenic nematodes (EPNs) are susceptible to a wide variety of environmental factors, including desiccation, which limit their usefulness as biocontrol agents. Although EPNs can be subjected to a gradual loss of water in their natural environment they are not full anhydrobiotes, being able to survive only moderate levels of desiccation at high relative humidities (rh). We investigated the desiccation tolerance of IJs of several Heterorhabditisspecies and strains when exposed to fast and slow desiccation regimes. We also investigated the behavioural and biochemical responses of Heterorhabditis IJs when exposed to 98% rh for 4 days. IJs of H. megidis UK211 (but not IJs of H. indica) aggregate into large clumps when desiccated at high rh, but unlike Steinernema spp., neither H. megidis nor H. indica IJs showed any tendency to coil. Preincubation of H. megidis UK211 IJs at high (98%) rh enhances their ability to survive for 150 min at 57% rh. We show that preincubation of H. megidis and H. indica at 98% rh induces the synthesis of glycerol but not of trehalose, whereas identical preincubation conditions do induce trehalose synthesis in Steinernema carpocapsae and Aphelenchus avenae. The biosynthesis of glycerol rather than trehalose by IJs of two species of Heterorhabditis in response to moderate levels of desiccation indicates that Heterorhabditis is unlikely to have the necessary metabolic responses to desiccation required to enable it to enter into a fully anhydrobiotic state. 相似文献
10.
Alessio Mortelliti Giulia Santulli Sanzo Luigi Boitani 《Biodiversity and Conservation》2009,18(5):1131-1145
The use of surrogate species in conservation planning has been applied with disappointing results on relatively large sets
of species. It could still prove useful for optimizing conservation efforts when considering a small set of species with similar
ecological requirements, however few field tests of this nature have been carried out. The aim of this research is to compare
the response of three arboreal rodent species—the fat dormouse (Glis glis), the hazel dormouse (Muscardinus avellanarius) and the red squirrel (Sciurus vulgaris)—to habitat loss and fragmentation, with the aim of identifying priorities for conservation and evaluating possible optimization
of conservation efforts under different scenarios: habitat restoration and selection of focal patches. We studied the distribution
of the three species in a sample of patches in a highly fragmented landscape in central Italy, using a patch-landscape scale
approach. The distribution was studied by using hair tubes, nestboxes and nocturnal surveys. The three species showed analogous
responses to increasing isolation and decreasing size of habitat patches; what differed however, was the magnitude of responses.
Our results show possible application of surrogacy within this restricted group of species, however several caveats arise
depending on the conservation strategy and available funding. If habitat restoration is the objective, then the fat dormouse
should be the target species for guiding size and isolation of patches. On the other hand, the magnitude of the differences
and patch requirements for this species, question the feasibility of these conservation actions. If selection of focal patches
for conservation is the objective then selecting the fat dormouse as a focal/umbrella species would overlook areas suitable
for the other two species. Feasible optimisation of conservation efforts may be possible only between the red squirrel and
the hazel dormouse. 相似文献
11.
Reexamination ofXanthoria persica, X. polycarpoides, X. lobulata gave evidence, that the thalli of these species are devoid of a lower cortex and rhizinae. Therefore, they do not fit the
definition of the genusXanthoria and are transferred toCaloplaca (under the new sectionXanthoriella) asCaloplaca persica, C. polycarpoides, andC. boulyi, respectively. — Details on development, anatomical structure, ecology and distribution are presented.
相似文献
12.
灵长类是森林生态系统中植物种子的主要传播者,有助于森林植被的更新,然而受研究方法的限制,灵长类种子传播潜力常被低估。为全面评估温带灵长类动物的种子传播潜力,采用直接观察法和粪便分析法评估珍稀濒危灵长类动物黑白仰鼻猴的种子传播潜力。于2018年11月—2019年10月采用直接观察法(瞬时扫描取样法)收集云岭省级自然保护区拉沙山黑白仰鼻猴的活动时间分配数据,获取每月取食果实的比例;同时每月收集黑白仰鼻猴的粪便,采用粪便分析法分拣猴粪中残留的植物种子,统计有完整种子残留的月份和粪便比例,应用这两种方法评估黑白仰鼻猴种子传播潜力及其差异。结果表明:直接观察法收集到黑白仰鼻猴取食果实的月份数为6个月(7—12月),月均取食果实的比例为(15.31±20.15)%,共取食13种果实;而粪便分析法发现黑白仰鼻猴粪粒内全年都有完整种子残留,粪便中月均完整种子残留比例(35.19±35.43)%,其中9月至第二年1月粪便中种子残留比例都大于50%,共取食18种果实;综合两种方法发现云南拉沙山黑白仰鼻猴共取食20种植物果实,具有较高的种子传播潜力。直接观察法可确定黑白仰鼻猴取食果实的物种数,而粪便分析法能... 相似文献
13.
Conservation of wildlife populations requires extensive knowledge of their habitat requirements, efficient methods to evaluate habitat quality, and an understanding of the value of fragments and edges. Kibale National Park, Uganda has areas that differ in the densities of 2 species of frugivorous monkeys—Cercopithecus mitis and Lophocebus albigena—including one on an edge and forest fragments outside the park that lack both species. We compared the basal area densities of important food trees with primate densities. The density of Cercopithecus mitis correlates most strongly with the basal area density of all types of food trees combined. The density of Lophocebus albigena does not correlate with the basal area densities of any category of food trees or with fruit availability. An index of their density—number of groups seen per km walked—correlates to fruit availability but with marginal significance. Lack of a relationship between the basal area densities of food trees and density of Lophocebus albigena may be the result of a mismatch in scale between the forest area measured and their large home ranges. We compared the unused area of forest to the other areas of the forest and the fragments and found it had higher basal area densities in all food tree categories for both species than the fragments and lower basal area densities of most categories than the other parts of the forest, indicating that the fragments are poor quality and would probably be unused even if dispersal were likely. 相似文献
14.
Keiji Iwasaki 《Ecological Research》1995,10(1):105-115
Consequences of ‘pushing contests’ between pairs of the intertidal pulmonate limpetSiphonaria sirius were analyzed, focusing on the relationship between dominance order and resting site fidelity. The pushing contests occurred
near patches ofEnteromorpha sp., their favorite algal food resource. Three or four dominance ranks were determined from the consequences of the contests
in different seasons. Individuals in lower dominance ranks tended to shift their resting sites significantly more than those
in higher ranks. The dominance order of limpets is considered to play an important role in migration by its effect on resting
site fidelity. Density dependent dispersal, from the lower to the upper part of limpets' habitats, was observed in late summer
to winter when desiccation was not a problem and food resources became abundant in less populated areas. In late spring to
summer, however, migration was directed downwards, from less to more populated areas, where desiccation pressure was relatively
weaker. This migration is considered to have a survival advantage, and the behavior of the limpets may have masked density-dependent
dispersal during the two seasons. Distribution of home site was also considered affected by aggressive social behavior during
the two periods. 相似文献
15.
Xander M. van der Burgt 《Kew Bulletin》2009,64(2):313-317
Summary
Lecomtedoxa plumosa Burgt (Sapotaceae), a new tree species from the southern part of Korup National Park in Cameroon, is described and illustrated.
The flowers show the characteristics of the genus Lecomtedoxa: for example the staminodes are free and placed alternately to the stamens and corolla lobes. The leaves of the new species
are clearly different from other Lecomtedoxa spp., but they look similar to the leaves of Gluema ivorensis, especially to those of the collections from Cameroon. In total 26 trees ≥ 10 cm dbh were found. The largest trees found
were 36 m high and 74 cm dbh. The trees grow in primary rain forest, in clusters of up to 10 trees on 2 ha, mixed with many
other tree species. The seed dispersal is ballistic. The conservation status of the species is assessed as Endangered, EN
D. 相似文献
16.
The leiognathid genus Nuchequula can be defined by the following combination of characters: mouth protruding downward; a narrow band of small, slender, villiform
teeth in both jaws; teeth on upper jaw strongly recurved; the lateral line almost complete; a dark blotch on the nape. Although
the genus was first established as a subgenus of Eubleekeria, it is here raised to generic level on the basis of the aforementioned morphological characters and recent molecular biological
evidence. The genus comprises six valid species: N. blochii (Valenciennes 1835), distributed in India and Thailand; N. flavaxilla sp. nov., occurring only at Panay I., Philippines; N. gerreoides (Bleeker 1851), widely distributed in the Indo-West Pacific, from the Persian Gulf to Cape York, Australia, and north to
Taiwan; N. glenysae sp. nov., from northern Australia and Ambon, Indonesia; N. longicornis sp. nov., from the Gulf of Thailand and Indonesia; and N. nuchalis (Temminck and Schlegel 1845), occurring in southern China including Taiwan, and southern Japan. Diagnostic characters of
the species belonging to the genus are as follows: N. blochii—breast scaled, cheek naked, and a conspicuous black blotch distally on spinous dorsal fin; N. flavaxilla sp. nov.—breast naked, dorsolateral body surface fully scaled, preorbital spine bicuspid and not expanded distally, and second
dorsal and anal fin spines conspicuously elongated; N. gerreoides—breast naked, anterior part of dorsolateral surface of body almost completely scaled, and second dorsal and anal fin spines
not conspicuously elongated; N. glenysae sp. nov.—breast completely scaled, cheek scaled, and unique complicated sensory canals present on the suborbital area, extending
to the nape; N. longicornis sp. nov.—breast naked, dorsolateral body surface fully scaled, preorbital spine bicuspid or tricuspid and extended distally,
and second dorsal fin spines only conspicuously elongated; N. nuchalis—breast naked, anterior part of dorsolateral surface of body widely naked, and a conspicuous dark blotch distally on spinous
dorsal fin. 相似文献
17.
Although gene flow is an important determinant of evolutionary change, the role of ecological factors such as specialization
in determining migration and gene flow has rarely been explored empirically. To examine the consequences of dispersal ability
and habitat patchiness on gene flow, migration rates were compared in three cactophagous longhorn beetles using coalescent
analyses of mtDNA sequences. Analyses of covariance were used to identify the roles of dispersal ability and habitat distribution
in determining migration patterns. Dispersal ability was a highly significant predictor of gene flow (p< 0.001), and was more important than any other factor. These findings predict that dispersal ability may be an import factor shaping
both microevolutionary and macroevolutionary patterns; this prediction is borne out by comparisons of species diversity in
cactus-feeding groups. 相似文献
18.
The autecology and ecophysiology of two selected periphytic species of Xanthophyceae (Tribonema fonticolum and T. monochloron) were studied from seasonal pools of the inundation area, in the upper part of the Lužnice River (Třeboňsko Biosphere Reserve,
Czech Republic) during winter–spring flood. Our studies have shown that these species differ in their ecological requirements
(their temperature and light optima; inorganic carbon sources for photosynthesis; and also their ability to survive freezing
and desiccation injuries). In our experiments, the optimal growth temperatures for both strains were higher than the temperatures
of the water they were collected and isolated from. Tribonema monochloron has the rate of photosynthesis several times higher than T. fonticolum. In addition, the optimal growth temperatures were about 3–4°C lower for Tribonema monochloron than for T. fonticolum. From our results, we concluded that both strains of Tribonema prefer low intensities of irradiance. Both Tribonema strains were determined as CO2 users, but we revealed the ability of T. fonticolum to use HCO3− in small amounts. In both Tribonema strains, 100% of the cells survived freezing down to −4°C. The cells’ viability after freezing at −40, −100 and −196°C was
much higher for T. monochloron (about 40%) than for T. fonticolum (about 4%). With respect to desiccation damages, at temperatures of +4 and +20°C, T. monochloron (the species better adapted to low temperatures) did not survive. In contrast, about 80% cells of T. fonticolum survived desiccation at both temperatures.
Handling editor: J. Padisak. 相似文献
19.
Ole A. Hoel 《Pal?ontologische Zeitschrift》2005,79(2):263-284
Strophomenid brachiopods belonging to the generaLeptaena andLepidoleptaena are described from the uppermost Llandovery — Ludlow succession of Gotland, Sweden. In Gotland,Lepidoleptaena comprises the single speciesL. poulseni, andLeptaena includes four species:L. rhomboidalis, L. sperion, L. depressa andL. parvirugata n. sp.L. depressa shows a considerable amount of morphological variation, which is recognised in the two new subspeciesLeptaena depressa visbyensis n. ssp. from the Llandoverian — Wenlockian Visby Formation, andL. depressa lata n. ssp. from the mid-Wenlockian Slite Group. The distribution of the different species is largely substrate-dependent, withLeptaena rhomboidalis andLepidoleptaena poulseni adapted to high-energy environments with firm substrates, whereas the remaining species preferred fine-grained substrates
in low-energy environments.
相似文献