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1.
We compared the thermoregulatory abilities of two insectivorous bat species, Tadarida teniotis (mean body mass 32 g) and Otonycteris hemprichii (mean body mass 25 g), that are of different phylogenetic origins and zoogeographic distributions but are sympatric in the Negev Desert. At night, both were normothermic. By day, both were torpid when exposed to ambient temperatures (T(a)) below 25 degrees Celsius, with concomitant adjustments in metabolic rate (MR). Otonycteris hemprichii entered torpor at higher T(a) than T. teniotis, and, when torpid, their body temperatures (T(b)) were 1 degrees -2 degrees Celsius and 5 degrees -8 degrees Celsius above T(a), respectively; MR was correspondingly reduced. At night, the lower critical temperature of T. teniotis was 31.5 degrees Celsius, and that of O. hemprichii was 33 degrees Celsius. Mean nocturnal thermoneutral MR of T. teniotis was 37% greater than that of O. hemprichii. At high T(a), evaporative water loss (EWL) increased markedly in both species, but it was significantly higher in T. teniotis above 38 degrees Celsius. In both species, the dry heat transfer coefficient (thermal conductance) followed the expected pattern for small mammals, by day and by night. Total EWL was notably low in normothermic and torpid animals of both species, much lower than values reported for other bats, indicating efficient water conservation mechanisms in the study species. Comparing thermoregulatory abilities suggests that O. hemprichii is better adapted to hot, arid environments than T. teniotis, which may explain its wider desert distribution. By both standard and phylogenetically informed ANCOVA, we found no differences in basal metabolic rate (BMR) between desert and nondesert species of insectivorous bats, substantiating previous studies suggesting that low BMR is a characteristic common to insectivorous bats in general.  相似文献   

2.
Settlement and post-settlement processes of the sea cucumber Holothuria scabra Jaeger were studied in the laboratory. Independent and paired choice experiments revealed that several substrates could induce metamorphosis into pentactulae, but that specific substrates favoured settlement. Leaves of seagrass Thalassia hemprichii, with or without their natural bio-film, yielded the highest settlement rates (4.8-10.5%). T. hemprichii was preferred as a settlement substrate over sand, crushed coral, several other plant species and artificial seagrass leaves with or without a bio-film. Only settlement on the seagrass, Enhalus acoroides, was similar to that recorded for T. hemprichii. In the absence of a substrate, the larvae delayed settlement for nearly 96 h and survival was less than 0.5%. Sand and crushed coral, either alone or together, induced settlement from <1.5% of the available larvae. The pentactulae found on sand, coral and in bare containers were 10-35% smaller than those on T. hemprichii leaves. Soluble extracts from T. hemprichii and E. acoroides successfully induced metamorphosis and settlement on clean plastic surfaces. Newly settled juveniles remained on the seagrass leaves for 4-5 weeks before migrating to sand at around 6 mm in length. Prior to this, the juveniles spent 4-5 days moving on and off the leaves. Once on the sand, the juveniles became deposit-feeders, but did not show the typical burrowing behaviour of older specimens until they reached around 11 mm in length. The larvae of H. scabra appear to actively select seagrass leaves, possibly through chemical detection. We hypothesise that larvae settling on seagrass have an increased chance of growth and survival because they are provided with a suitable substrate on which to grow, and a bridge to sand substrates as they become deposit-feeders.  相似文献   

3.
The effects of CO2 enrichment on various ecophysiological parameters of tropical seagrass Thalassia hemprichii(Ehrenb.)Aschers were tested.T.hemprichii,collected from a seagrass bed in Xincun Bay,Hainan island of Southern China,was cultured at 4 CO2(aq)concentrations in flow-through seawater aquaria bubbled with CO2.CO2 enrichment considerably enhanced the relative maximum electron transport rate(RETRmax)and minimum saturating irradiance(Ek)of T.hemprichii.Leaf growth rate of CO2enriched plants was significantly higher than that in unenriched treatment.Nonstructural carbohydrates(NSC)of T.hemprichii,especially in belowground tissues,increased strongly with elevated CO2(aq),suggesting a translocation of photosynthate from aboveground to belowground tissues.Carbon content in belowground tissues showed a similar response with NSC,while in aboveground tissues,carbon content was not affected by CO2 treatments.In contrast,with increasing CO2(aq),nitrogen content in aboveground tissues markedly decreased,but nitrogen content in belowground was nearly constant.Carbon: nitrogen ratio in both tissues were obviously enhanced by increasing CO2(aq).Thus,these results indicate that T.hemprichii may respond positively to CO2-induced acidification of the coastal ocean.Moreover,the CO2-stimulated improvement of photosynthesis and NSC content may partially offset negative effects of severe environmental disturbance such as underwater light reduction.  相似文献   

4.
The effects of CO2 enrichment on various ecophysiological parameters of tropical seagrass Thalassia hemprichii(Ehrenb.)Aschers were tested.T.hemprichii,collected from a seagrass bed in Xincun Bay,Hainan island of Southern China,was cultured at 4 CO2(aq)concentrations in flow-through seawater aquaria bubbled with CO2.CO2 enrichment considerably enhanced the relative maximum electron transport rate(RETRmax)and minimum saturating irradiance(Ek)of T.hemprichii.Leaf growth rate of CO2enriched plants was significantly higher than that in unenriched treatment.Nonstructural carbohydrates(NSC)of T.hemprichii,especially in belowground tissues,increased strongly with elevated CO2(aq),suggesting a translocation of photosynthate from aboveground to belowground tissues.Carbon content in belowground tissues showed a similar response with NSC,while in aboveground tissues,carbon content was not affected by CO2 treatments.In contrast,with increasing CO2(aq),nitrogen content in aboveground tissues markedly decreased,but nitrogen content in belowground was nearly constant.Carbon: nitrogen ratio in both tissues were obviously enhanced by increasing CO2(aq).Thus,these results indicate that T.hemprichii may respond positively to CO2-induced acidification of the coastal ocean.Moreover,the CO2-stimulated improvement of photosynthesis and NSC content may partially offset negative effects of severe environmental disturbance such as underwater light reduction.  相似文献   

5.
Twenty-three species representative of 15 heteronemertean genera are recorded from Antarctic and Subantarctic waters south oflatitude 50oS. Five new genera are established and seven new species are fully described and illustrated. These are Cephalurichus antarcticus gen. et sp. nov., Dokonemertes magellanensis gen. et sp. nov., Dokonemertes macquariensis sp. nov., Micrellides multiperula gen. et sp. nov., Paramicrurinella falklandica gen. et sp. nov., Parborlasia landrumae sp. nov. and Zodionemertes chilensis gen. et sp. nov. Baseodiscus antarcticus Baylis, Antarctolineus scotti (Baylis), Lineus longifissus (Hubrecht) and Parborlasia fueguina Serna de Esteban & Moretto are redescribed and illustrated and the nature of rhynchodaeal pouches protruding into the cephalic blood lacunae of Parborlasia corrugatus (Mcintosh) is reexamined and discussed. The main anatomical characters of the remaining 11 species are recorded and it is concluded that of these only Parapolia grytvikenensis Wheeler, Cerebratulus malvini Wheeler, Chilineus glandulosa (Burger), Huilkia ushuaiensis Serna de Esteban & Moretto, Micrura pacifica Friedrich and Wiolkenia friedrichi Serna de Esteban & Moretto can at present be accepted as valid, although incompletely described, taxa. Cerebratulus larseni Wheeler, Cerebratulus validus Bürger, Lineus autrani Joubin and Lineus turqueli Joubin are so poorly and inadequately described that their taxonomic status cannot be verified, and the recorded occurrence of Lineus nigricans Burger in southern latitudes cannot be substantiated on the available evidence. Maps showing the recorded distribution of all the species are included and a key to the 18 validated species is provided.  相似文献   

6.

Aim

Introduced species spreading to natural ecosystems is a leading cause of environmental change and a key feature of the Anthropocene. While there have been many studies of the traits of introduced and invasive species, less is known about the traits that affect a species' chances of reaching and establishing in new areas. We asked whether British species that are present in Australia have different traits to British species that are not present in Australia.

Location

Great Britain and Australia.

Methods

We compiled a list of all vascular plant species from Great Britain and divided them into those that are present in Australia (395 species) and those that are not present in Australia (1171 species). We compiled data for each species' seed mass, seedbank longevity, maximum plant height, flower size, flower colour and geographical extent in the British Isles. We conducted independent sample t-tests for continuous variables and Chi-squared tests for categorical variables to determine differences between groups.

Results

We found British species present in Australia have, on average, larger geographic extents in the British Isles, longer periods of seed bank longevity (mean ~3 months as opposed to ~3 weeks), and maximum heights that are on average 36% taller than British species that are not present in Australia. However, British species present in Australia did not have significantly different flower size, flower colour or seed mass from British species that are not present in Australia.

Main Conclusions

British species that are present in Australia and British species that are not present in Australia differ in several traits. These differences likely result from a combination of factors including introduction biases, environmental filters during establishment and stochasticity. Our results suggest that humans may be consciously and unconsciously selecting species for introduction. Some of the traits that are associated with an increased chance of a species being transported to/establishing in a new range also contribute to invasiveness. Thus, anthropogenic introduction biases could contribute to an increased risk of ecosystem invasion.  相似文献   

7.
Coucals are large, predatory, primarily ground‐dwelling cuckoos of the genus Centropus, with 26 extant species ranging from Africa to Australia. Their evolutionary and biogeographical history are poorly understood and their fossil record almost non‐existent. Only one species (Centropus phasianinus) currently inhabits Australia, but there is now fossil evidence for at least three Pleistocene species. One of these (Centropus colossus) was described from south‐eastern Australia in 1985. Here we describe additional elements of this species from the same site, and remains of two further extinct species from the Thylacoleo Caves of the Nullarbor Plain, south‐central Australia. The skeletal morphology and large size of the three extinct species indicates that they had reduced capacity for flight and were probably primarily ground‐dwelling. The extinct species include the two largest‐known cuckoos, weighing upwards of 1 kg each. They demonstrate that gigantism in this lineage has been more marked in a continental context than on islands, contrary to the impression gained from extant species. The evolutionary relationships of the Australian fossil coucals are uncertain, but our phylogenetic analysis indicates a possible close relationship between one of the Nullarbor species and extant Centropus violaceus from the Bismarck Archipelago. The presence of three coucals in southern Australia markedly extends the geographical range of the genus from tropical Australia into southern temperate regions. This demonstrates the remarkable and consistent ability of coucals to colonize continents despite their very limited flying ability.  相似文献   

8.
Abstract  Caliothrips fasciatus is native to the USA and western Mexico and overwintering adults are regular contaminants in the 'navel' of navel oranges exported from California, USA to Australia, New Zealand and elsewhere. Due to the long history of regular interceptions of C. fasciatus in Australia, a survey for this thrips was undertaken around airports, seaports, public recreational parks and major agricultural areas in the states of Queensland, New South Wales, Victoria, South Australia and Western Australia to determine whether C. fasciatus has successfully invaded Australia. Host plants that are known to support populations of C. fasciatus , such as various annual and perennial agricultural crops, urban ornamentals and weeds along with native Australian flora, were sampled for this thrips. A total of 4675 thrips specimens encompassing at least 76 species from a minimum of 47 genera, and three families were collected from at least 159 plant species in 67 families. Caliothrips striatopterus was collected in Queensland, but the target species, C. fasciatus , was not found anywhere. An undescribed genus of Thripidae, Panchaetothripinae, was collected from ornamental Grevillea (var. Robyn Gordon) at Perth (Western Australia) Domestic Airport, and is considered to be a native Australian species. This survey has provided valuable information on the background diversity of thrips species associated with various native and exotic plant species around major ports of entry and exit for four of five states in Australia. We suggest that the major reason C. fasciatus has not established in Australia is due to high adult mortality in navels that are kept at low storage temperatures (2.78°C) during an 18- to 24-day transit period from California to Australia.  相似文献   

9.
Australian species of Sinella (Sinella) Brook (Collembola: Entomobryidae)   总被引:1,自引:0,他引:1  
Abstract  The Australian subgenus Sinella ( Sinella ) Brook is revised. Two species are recognised. A new species from New South Wales and South Australia, Sinella ( Sinella ) samueli , is described and the widely distributed species Sinella ( Sinella ) termitum Schött is redescribed based on examination of a specimen from the type series and fresh collections from a wide range of localities in south-eastern Australia. New patterns of chaetotaxy for the genus are described from these species.  相似文献   

10.
Species-area curves are presented for three woodlands with herbaceous understoreys in western Victoria. Australia. Up to 93 species of vascular plant were recorded from 128 m2. making these woodlands one of the richest terrestrial vegetations recorded from temperate Australia. Species richness at this scale is comparable with that recorded from kwongan (sclerophyllous shrubland) in south-western Australia. Up to 45 species were recorded from 10 m2. At this scale the woodlands are the richest terrestrial vegetation recorded from Australia, and among the richest in the world, being comparable with the renowned chalk grasslands of Europe. The growth-form spectra of these woodlands differ dramatically from those of other species rich communities in temperate Australia due to the abundance of herbs and dearth of woody species. In contrast to species rich woodlands in Israel and California, perennial herbs rather than annuals predominate. Although the woodlands studied are protected in conservation reserves, regional floristic surveys are required to determine the geographic extent, floristic variability and conservation status of herb-rich woodlands in Victoria.  相似文献   

11.
Short M  Huynh C 《ZooKeys》2011,(156):105-122
The penicillate genus Unixenus Jones, 1944 is widespread, with species found in Africa, Madagascar, India and Australia. Each of the two Australian species was originally described from single samples from Western Australia. In this study, collections of Penicillata from museums in all states of Australia were examined to provide further details of the two described species, to revise the diagnoses for both the genus and the species, and to better understand the distribution of the two species in Australia. In addition, two new species Unixenus karajinensissp. n. and Unixenus corticolussp. n. are described.  相似文献   

12.
13.
Rix MG  Harvey MS 《ZooKeys》2012,(191):1-62
The Assassin Spiders of the family Archaeidae from southern Australia are revised, with a new genus (Zephyrarchaeagen. n.) and nine new species described from temperate, mesic habitats in southern Victoria, South Australia and south-western Western Australia: Zephyrarchaea austinisp. n., Zephyrarchaea barrettaesp. n., Zephyrarchaea grayisp. n., Zephyrarchaea janineaesp. n., Zephyrarchaea maraesp. n., Zephyrarchaea markisp. n., Zephyrarchaea melindaesp. n., Zephyrarchaea porchisp. n. and Zephyrarchaea vichickmanisp. n. Specimens of the type species, Zephyrarchaea mainae (Platnick, 1991), comb. n., are redescribed from the Albany region of Western Australia, along with the holotype female of Zephyrarchaea robinsi (Harvey, 2002) comb. n. from the Stirling Range National Park. The previously described species Archaea hickmani Butler, 1929 from Victoria is here recognised as a nomen dubium. A key to species and multi-locus molecular phylogeny complement the species-level taxonomy, with maps, habitat photos, natural history information and conservation assessments provided for all species.  相似文献   

14.
For a variety of coral species, we have studied the molecular origin of their coloration to assess the contributions of host and symbiont pigments. For the corals Catalaphyllia jardinei and an orange-emitting color morph of Lobophyllia hemprichii, the pigments belong to a particular class of green fluorescent protein-like proteins that change their color from green to red upon irradiation with approximately 400 nm light. The optical absorption and emission properties of these proteins were characterized in detail. Their spectra were found to be similar to those of phycoerythrin from cyanobacterial symbionts. To unambiguously determine the molecular origin of the coloration, we performed immunochemical studies using double diffusion in gel analysis on tissue extracts, including also a third coral species, Montastrea cavernosa, which allowed us to attribute the red fluorescent coloration to green-to-red photoconvertible fluorescent proteins. The red fluorescent proteins are localized mainly in the ectodermal tissue and contribute up to 7.0% of the total soluble cellular proteins in these species. Distinct spatial distributions of green and cyan fluorescent proteins were observed for the tissues of M. cavernosa. This observation may suggest that differently colored green fluorescent protein-like proteins have different, specific functions. In addition to green fluorescent protein-like proteins, the pigments of zooxanthellae have a strong effect on the visual appearance of the latter species.  相似文献   

15.
16.
The tropical Indo-Pacific genus Excoecaria L. (Euphorbiaceae) has several closely related species in Australia whose taxonomic relationships are unclear. The most widely reported species in Australia is the mangrove species Excoecaria agallocha L. (type species), whose taxonomic and geographic limits are difficult to define from its closely related species or sub-species. Two additional taxa have also been described but not clearly differentiated from the type species: Excoecaria dallachyana Baillon and Excoecaria ovalis Endl. This project aimed to determine the taxonomic relationships of the Australian Excoecaria species using both leaf morphological data and DNA sequence data from the internal transcribed spacer (ITS) region of ribosomal genes. The nucleotide differences in the examined ITS1 region show that E. agallocha from eastern Australia and E. ovalis from Western Australia respectively, are genetically uniform within species but differ from each other consistently, thus supporting species status. The leaf morphological data also support this view: single factor analysis of variance consistently separated E. ovalis from E. agallocha on the basis of leaf width, leaf length and length of petiole. In contrast, E. ovalis from the Gulf of Carpentaria differs only slightly from E. ovalis in Western Australia, but no evidence was found to suggest any leaf morphological differentiation within this species. The analysis also suggests that E. dallachyana is not closely related to either mangrove species E. agallocha or E. ovalis, despite superficial morphological similarities.  相似文献   

17.
The biosecurity risks from many plant-parasitic nematode (PPN) species are poorly known and remain a major challenge for identifying potentially invasive species. A self organising map (SOM) was used to prioritise biosecurity risks from PPN to the whole of continental Australia as well as each of the states and the Northern Territory separately. The SOM used the recorded worldwide distributions of 250 systematically selected species from 43 genera, and identified 18 different countries spanning Asia, Africa, North and Central America, Europe and the Pacific with very similar PPN assemblages to Australia as a whole. Many of the species in these countries are not recorded in Australia, and therefore pose a biosecurity risk. Analysed separately, the states and territories were identified as forming five separate clusters, each with a different region of the world, and with different characteristic PPN. Many of the PPN found in the regions clustered with an Australian state have not been recorded from anywhere in Australia, and others have very restricted distributions within Australia, thus posing different biosecurity risks. The SOM analysis ranked the risks of the different PPN based on likelihoods of establishment. The rankings confirmed the risks from frequently quarantined PPN, but more importantly identified species, which upon further investigation could be new threats. This method can be used to identify previously overlooked species for more detailed risk assessments.  相似文献   

18.
19.
The genus Psix Kozlov & Lê (Hymenoptera: Scelionidae) is revised from a worldwide perspective. Twelve species are described as new: annulatus [Cameroon], asper [Uganda], aulax [Australia], confluus [Sri Lanka], flavicoxa [Ivory Coast, Zimbabwe], fusm [Australia], lacunatus [Pakistan east to Taiwan, south to Australia], metopa [Australia], rasilis [Ivory Coast, Gambia], sulcifer [Malaysia], viriosus [India east to Philippine Is.] and watshami [E. Africa, Madagascar] . Psix abnormis Kozlov & Lê [W. Africa east to at least India], glabris-crobus (Girault) nxomb. [Australia], olympus (Dodd) n.comb. [Australia], saccharicola (Mani) n.comb. [India], striaticeps (Dodd) n.comb. [W. Africa east to India, Madagascar] and tunetanus (Mineo and Szabó) n.comb. [Tunisia, Gambia, Ivory Coast, Saudi Arabia, S.W. Nearctic, Venezuela] are redescribed. An identification key for the species of Psix is presented. The relationships among species are discussed. The earliest derived species are generally found in Australia and southeast Asia. The more apomorphic species occur generally in Africa, southwest Asia and India. The distribution of Psix tunetanus has possibly been influenced by man. Details of the relationship with Trissolcus and Archi-phanurus are unclear; the position of Psix within the subfamily is therefore also obscure.  相似文献   

20.
The genus Thecotheus is reported in Australia for the first time. A new species, Thecotheus urinamans is described and illustrated and included in a key to all known species of the genus. Critical macro- and micromorphological comparisons are presented to distinguish the new species from several closely related species, particularly the widespread fungus Thecotheus crustaceus. Thecotheus urinamans was growing on rotting, moist, plant litter from an experimental plot treated with urea (ammonia) in the indigenous jarrah (Eucalyptus marginata) forest of Western Australia.  相似文献   

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