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Knowledge of the dispersal capacity of species is crucial to assess their extinction risk, and to establish appropriate monitoring and management strategies. The Providence petrel (Pterodroma solandri) presently breeds only at Lord Howe Island (~32,000 breeding pairs) and Phillip Island-7 km south of Norfolk Island (~20 breeding pairs). A much larger colony previously existed on Norfolk Island (~1,000,000 breeding pairs) but was hunted to extinction in the 18th Century. Differences in time of return to nesting sites are presently observed between the two extant colonies. Information on whether the Phillip Island colony is a relict population from Norfolk Island, or a recent colonization from Lord Howe Island, is essential to assess long-term sustainability and conservation significance of this small colony. Here, we sequenced the mitochondrial cytochrome b gene and 14 nuclear introns, in addition to genotyping 10 microsatellite loci, to investigate connectivity of the two extant P. solandri populations. High gene flow between populations and recent colonization of Phillip Island (95 % HPD 56–200 ya) are inferred, which may delay or prevent the genetic differentiation of these insular populations. These results suggest high plasticity in behaviour in this species and imply limited genetic risks surrounding both the sustainability of the small Phillip Island colony, and a proposal for translocation of Lord Howe Island individuals to re-establish a colony on Norfolk Island.  相似文献   

3.
Interactions between trees and ectomycorrhizal fungi are critical to the growth and survival of both partners. However, ectomycorrhizal symbiosis has barely been explored in endangered trees, and no information is available regarding soil spore banks of ectomycorrhizal fungi from forests of threatened trees. Here, we evaluated soil spore banks of ectomycorrhizal fungi from endangered Japanese Douglas-fir (Pseudotsuga japonica) forests using bioassay approaches with congeneric P. menziesii and Pinus densiflora seedlings in combination with molecular identification techniques. Rhizopogon togasawariana was predominant in soil propagule banks and was found in all remaining P. japonica forests when assayed with P. menziesii, while no colonization of this fungus was observed on Pinus seedlings. Given the observed specificity of R. togasawariana for P. menziesii and its phylogenetic position within the Pseudotsuga-specific Rhizopogon lineage, its geographical distribution is likely restricted to the remaining Japanese Douglas-fir forests, indicating a high extinction risk for this fungus as well as its endangered host. Spore banks of R. togasawariana remained highly infective after preservation for 1 year or heat treatment at 70 °C, suggesting an ecological strategy of establishing ectomycorrhizal associations on regenerating Japanese Douglas-fir seedlings after disturbance, as observed in other Rhizopogon–Pinaceae combinations. Therefore, the regeneration of Japanese Douglas-fir seedlings may depend largely on the soil spore banks dominated by R. togasawariana, which has co-evolved with the Japanese Douglas-fir for over 30 million years. More attention must be paid to underground ectomycorrhizal fungi for the conservation of endangered tree species, especially in the era of human-induced mass extinction.  相似文献   

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Beaucarnea (Nolinaceae) is a Mexican and Guatemalan genus that inhabits dry tropical areas. Most of the species are endangered under the Mexican legislation because they have a high horticultural demand and are threatened by habitat destruction. Species are difficult to recognize, since their differences are a mixture of trunk, inflorescence and fruit characters frequently absent in herbarium specimens. The aim of this work is to describe the foliar anatomy of the 11 species of Beaucarnea in search of characters with taxonomic value to sustain the generic subdivision, and to provide a key for specimens determination based on leaf and growth form. We found that four species (B. compacta, B. gracilis, B. purpusii and B. stricta) have a grooved leaf outline in transverse section, whereas the rest of the species are undulated. Other characters, such as epicuticular waxes, stomatal distribution and density, marginal teeth length and leaf apex provide valuable characters for species determination.  相似文献   

6.
Geometric morphometrics and molecular methods are effective tools to study the variability of stingless bee populations and species that merit protection given their worldwide decline. Based on previous evidence of cryptic lineages within the Scaptotrigona genus, we tested the existence of multiple evolutionary lineages within the species S. mexicana and we investigated the status of S. pectoralis. By analyzing their population structure, we found differences between the Pacific and Atlantic populations of each of these species, although geometric morphometrics of the wing only confirmed these results in S. mexicana. There was a tendency towards enhanced genetic differentiation over larger distances in the Atlantic populations of both species but not in the Pacific populations. These results revealed a pattern of differentiation among evolutionary units and a specific distribution of genetic diversity within these Scaptotrigona species in Mesoamerica, suggesting the need for future taxonomic revisions, as well as activities aimed at management and conservation.  相似文献   

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The mahseers (Tor, Neolissochilus and Naziritor) are an important group of fishes endemic to Asia with the conservation status of most species evaluated as threatened. Conservation plans to revive these declining wild populations are hindered by unstable taxonomy. Molecular phylogeny studies with mitochondrial genome have been successfully used to reconstruct the phylogenetic tree and to resolve taxonomic ambiguity. In the present study, complete mitochondrial genome of Tor tor has been sequenced using ion torrent next-generation sequencing platform with coverage of more than 1000 ×. Comparative mitogenome analysis shows higher divergence value at ND1 gene than COI gene. Further, occurrence of a distinct genetic lineage of T. tor is revealed. The phylogenetic relationship among mahseer group has been defined as Neolissochilus hexagonolepis ((T. sinensis (T. putitora, T. tor), (T. khudree, T. tambroides)).  相似文献   

9.
The freshwater pearl mussel Margaritifera margaritifera L. is one of the most endangered freshwater mussels in the world. Effective conservation of threatened species requires not only ecological, but also genetic information from the target species and populations. Since low genetic diversity can reduce the ability of a species to adapt to environmental changes, maintaining genetic diversity has been identified as one of the key elements in successful conservation programs. We examined genetic variation of the freshwater pearl mussel from the River Vuokkijoki, Karelia, Russia. We sequenced a fragment of the cytochrome c oxidase subunit I gene (COI) from 22 individuals and compared the data to 32 previously published COI sequences available in GenBank. We identified 10 different COI haplotypes in the sequenced samples, three of which had not been previously reported. Our results show that the River Vuokkijoki has high genetic diversity and suggest that the colonization of this northern freshwater pearl mussel population might have occurred from multiple and even distant refugia. Therefore, the freshwater pearl mussel population of the River Vuokkijoki is valuable for the conservation of the whole species.  相似文献   

10.
An annotated list of cartilaginous fish (Chondrichthyes: Elasmobranchii, Holocephali) is given for the first time in the 200-year history of studying the ichthyofauna of Sakhalin Island and adjacent waters of the southern part of the Sea of Okhotsk (including the coast of Hokkaido Island) and the northern Sea of Japan. The list includes 43 species in two classes, eight orders, 16 families, and 25 genera. Information on nature conservation status, English and Latin names, depths of habitat, and distribution within the coastal waters of Sakhalin are presented. For a number of species caught off the coast of Sakhalin and in the adjacent waters, information is provided on collection specimens confirming their presence in the region under study. For a number of species of the Rajiformes order (Arctoraja parmifera, A. smirnovi, A. simoterus), the modern ranges and taxonomic status are being refined in the light of new data. The taxonomic status of the so-called “disputed” taxa is discussed as well as the validity of the species considered in the Bathyraja matsubarai complex. Based on the study of the collections, Arctoraja simoterus, previously unknown in the waters of Russia, as well as Myliobatis tobijei, caught in the Bering Sea, has been discovered, which significantly expands the range of this species to the north.  相似文献   

11.
Sound is an inherent component of the environment that provides conditions and information necessary for many animal activities. Soniferous species require specific acoustic and physical conditions suitable for their signals to be transmitted, received, and effectively interpreted to successfully identify and utilize resources in their environment and interact with conspecifics and other heterospecific organisms. We propose the Acoustic Habitat Hypothesis to explain how the acoustic environment influences habitat selection of sound-dependent species. We postulate that sound-dependent species select and occupy habitats with unique acoustic characteristics that are essential to their functional needs and conducive to the threshold of sound frequency they produce and detect. These acoustic habitats are based on the composition of biophony, geophony, and technophony in the soundscape and on the biosemiotics mechanisms described in the eco-field hypothesis. The Acoustic Habitat Hypothesis initiates questions of habitat selection that go beyond the physical attributes of the environment by applying ecoacoustics theory. We outline the theoretical basis of the Acoustic Habitat Hypothesis and provide examples from the literature to support its assumptions. The concept of acoustic habitats has been documented in the literature for many years but here, we accurately and extensively define acoustic habitat and we put this concept into a unified theory. We also include perspectives on how the Acoustic Habitat Hypothesis can stimulate a paradigm shift in conservation strategies for threatened and endangered species.  相似文献   

12.
New and rare liparid fishes (Liparidae, Scorpaeniformes) are found and described. Careproctus armatus Andriashev, 1991 sampled off the South Sandwich Islands (at a depth 2281–2369 m); it is the second record of the species. Four species are collected in the vicinity of the South Shetland Islands: Careproctus parini Andriashev et Prirodina, 1990 (off King George Island, 573–861 m), Paraliparis meganchus Andriashev, 1982 (off Elephant Island, 559 m), P. monoporus Andriashev et Neyelov, 1979 (off Elephant Island, 559 m) and Paraliparis specimens, most similar to P. tompkinsae Andriashev, 1992 (off King George Island, 766–861 m). Paraliparis charcoti Duhamel, 1992 recorded at the eastern part of the Weddell Sea (475–633 m). Paraliparis, most similar to P. tetrapteryx Andriashev et Neelov, 1979, found in the Southwestern Atlantic (1200 m). Four new species are described. Paraliparis porcus sp. nov. based on one male SL 85 mm from off the South Shetland Islands (Elephant Island, 332–374 m). Paraliparis acutidens sp. nov. described from the juvenile SL 115 mm, sampled in the western part of the Scotia Sea (3721–3723 m). Paraliparis kocki sp. nov. known from 3 adults caught in the depression of the Bransfield Strait (1914–1920 m), isolated from the Weddell Sea by shallower waters. The only specimen of the Paraliparis mexicanus sp. nov. collected in the tropical Pacific off Mexico at depth not more than 900 m.  相似文献   

13.
An analysis of the variation patterns in the three Pacific Coast maritime species ofAbronia (Nyctaginaceae) based on 95 population studies, is presented in the form of scatter diagrams. The relationship of this group of species to other members of the genus, such asA. gracilis Benth., is considered. Despite widespread evidence of hybridization and introgression, the three maritime species (A. latifolia Eschsch.,A. maritima Nutt. ex S. Wats., andA. umbellata Lam.) maintain their distinctness. Most of the taxonomic segregants in this group have been based on what appear to be hybrid or introgressed individuals, many of which closely resemble members of a series of artificial hybrids made in the greenhouse. The chromosome number of all three species is estimated as 2n = ca. 46. The species are shown to differ markedly in ecological preference:A. latifolia competing successfully on stable areas of dunes from Vancouver Island, British Columbia, to Santa Barbara Co., California;A. maritima being the major foredune former along the strand from San Luis Obispo Co., California, south to Nayarit, Mexico; andA. umbellata occurring on more stable dunes from San Luis Obispo to San Diego Co., California, and sporadically north and south of this area. The latter species is pollinated chiefly by nocturnal insects and is fragrant in the evening, whereas the other two have diurnal flowers. One widespread and two rarer, more northern subspecies ofA. umbellata are recognized in the taxonomic revision, while the other two species are not subdivided taxonomically.  相似文献   

14.
During the course of a taxonomic study of Chamaecrista sect. Absus subsect. Absus ser. Rigidulae, a new species of Chamaecrista was discovered growing in disturbed areas of Cerrado sensu stricto in the municipality of Alto Paraíso de Goiás. Chamaecrista elata is herein described and illustrated. Morphological comparison with related species and information on geographical distribution, environmental preferences, conservation status, and phenology are provided.  相似文献   

15.
The American burying beetle, Nicrophorus americanus, is a federally endangered insect that once occurred in 35 US states and 3 Canadian provinces. Today, it remains at the periphery of its former range with the largest populations concentrated in Nebraska and Oklahoma. We assessed beetle occurrence records throughout the western ranges in Nebraska and Oklahoma, but excluded a small eastern population on Block Island, Rhode Island. We compiled more than 2500 presence–absence records and used GIS-based random forest models to create distribution maps throughout the current western range of the American burying beetle based on habitat characteristics within 800 m of each trap. We also used generalized linear models to identify habitat characteristics associated with N. americanus occurrences and to document differences between northern and southern habitat associations. In its northern range, N. americanus was associated with wetter areas while avoiding agricultural and urban areas. In the southern range, N. americanus was associated with sandy soils, hayfields, and native forests and grasslands, while avoiding human population centers and agricultural areas. Our N. americanus distribution maps for the northern and southern regions highlight areas where N. americanus is likely to occur, providing a tool that may improve current management. This first attempt at a range-wide model of American burying beetle occurrences revealed important differences among regions and can improve region-specific management and conservation.  相似文献   

16.
Eutrema edwardsii R.Br. (Brassicaceae) is an arctic-alpine mustard with a circumpolar distribution. Its closest relative, Eutrema penlandii Rollins, is a federally listed, threatened species that is endemic to the Mosquito Range in the Southern Rocky Mountains of Colorado, USA. As part of a larger project addressing the systematics of this species complex in North America, we conducted chromosome counts, flow cytometry, and allozyme analysis to test the hypothesis that these taxa comprise an autopolyploid complex. Within that context, it should be noted that a chromosome count has not been reported previously for E. penlandii. Results obtained from mitotic counts obtained for two populations of E. penlandii reveal this taxon to be diploid. Diploidy was confirmed using flow cytometry for an additional 15 individuals representing four populations. Previously published chromosome counts for E. edwardsii reveal a polyploid complex of tetraploid, hexaploid, and octaploid populations for which an autopolyploid origin has been presumed. However, allozyme analysis revealed an allopolyploid origin for E. edwardsii, as evidenced from fixed heterozygosity at six loci. Although our data suggest that E. penlandii is a close relative of one of the progenitors of E. edwardsii, the taxonomic identity of the other progenitor(s) cannot be elucidated from these data. The data reported herein support the recognition of E. penlandii as taxonomically distinct, which has implications for conservation, and reveal cryptic variation within E. edwardsii.  相似文献   

17.
Understanding ecological requirements of endangered species is a primary precondition of successful conservation practice. Regrettably, we know surprisingly little about the life history of numerous threatened insects, and about their use of larval host plants in particular. The brown butterflies (Nymphalidae: Satyrinae) have traditionally been considered polyphagous on grasses and indiscriminatory in their oviposition behavior. However, detailed studies on several species have revealed local specialization in host plant use as well as the decisive role of microlimatic conditions as determinants of habitat quality. The present study addresses host plant relationships in the endangered brown butterfly Coenonympha hero (L.) at the northern limit of its European distribution. We combine laboratory-based host preference and performance tests with an analysis of microhabitat use by adult butterflies in the field. Both lines of evidence suggest that C. hero is polyphagous enough not to be associated with one particular host species. Oviposition choices of C. hero are not driven by host plant species but rather by structural characteristics of the substrate. The preferred rigid needle-like structures may serve as cues of ‘transparent’ vegetation which allows the larvae to benefit from sunlight reaching the lower strata of the tuft. Our results suggest that conservation efforts should prioritize microclimatic parameters, rather than the presence of any particular host plant species, as decisive determinants of habitat quality in C. hero.  相似文献   

18.
Many doubts still exist about which freshwater mussel Unio species inhabit Northwest Africa. While some authors refer to the presence of Unio delphinus in the Atlantic North African basins of Morocco, a recent International Union for Conservation of Nature (IUCN) assessment performed on Moroccan Unio species, recognised the existence of a distinct species, Unio foucauldianus, with a critically endangered conservation status. The present study delivered new genetic, morphological, and geographical distribution data on two Unio species (i.e. U. delphinus and U. foucauldianus) greatly increasing the almost non-existent data on these taxa. Bayesian phylogenetic analysis revealed two highly supported geographically concordant clades, which diverged by 3.2?±?0.6 % (uncorrected p distance): the first distributed across Iberia and corresponding to U. delphinus, and the second distributed across Morocco, corresponding to U. foucauldianus. These results were corroborated by the analysis of ten newly developed microsatellite loci as well as shell morphometry. We suggest that the IUCN critically endangered conservation status of U. foucauldianus should be revised and probably down-listed since its actual distribution is much wider than previously described. Phylogenetic relationships with the other Unio species were resolved, showing that U. delphinus and U. foucauldianus fall inside the pictorum lineage. The estimated molecular rate reported herein (0.265?±?0.06 % per million years) represents the first for the Unionida and could be used as a reference in future studies.  相似文献   

19.
The conservation of narrow endemic species relies on accurate information regarding their population structure. Juglans hopeiensis Hu (Ma walnut), found only in Hebei province, Beijing, and Tianjin, China, is a threatened tree species valued commercially for its nut and wood. Sequences of two maternally inherited mitochondrial markers and two maternally inherited chloroplast intergenic spacers, three nuclear DNA sequences, and allele sizes from 11 microsatellites were obtained from 108 individuals of J. hopeiensis, Juglans regia, and Juglans mandshurica. Haplotype networks were constructed using NETWORK. Genetic diversity, population differentiation, and analysis of molecular variance (AMOVA) were used to determine genetic structure. MEGA was used to construct phylogenetic trees. Genetic diversity of J. hopeiensis was moderate based on nuclear DNA, but low based on uniparentally inherited mitochondrial DNA and chloroplast DNA. Haplotype networks showed that J. hopeiensis haplotypes were different than haplotypes found in J. regia and J. mandshurica. Allelic variants in nuclear genes that were shared among J. hopeiensis populations were not found in J. regia or J. mandshurica. Sampled populations of J. hopeiensis showed clear genetic structure. The maximum parsimony (MP) tree showed J. hopeiensis to be distinct from J. mandshurica but threatened by hybridization with J. regia and J. mandshurica. J. hopeiensis populations are strongly differentiated from sympatric Juglans species, but they are threatened by small population sizes and hybridization.  相似文献   

20.
Currently, many species are facing the risk of extinction, as it one of the most serious conservation issues. Many conservation programs have evolved to prevent species extinction; however, developing these strategies may prove to be difficult for the species itself, which includes different cryptic species. In this paper, we document the invasion of non-native cryptic species of ancylin limpets, Ferrissia californica, with a molecular phylogenetic analysis. Three species (F. nipponica, F. japonica, Gundlachia japonica) have been described as native, whereas the present analysis shows that most of them are actually non-native F. californica, having been introduced from North America and spreading throughout Japan. In addition, we found a few subpopulations of the cryptic native species of the ancylin limpets, though the native limpet species is very rare, and has limited distribution. The conservation status assigned to ancylin limpets on the Japanese red list is problematic, because F. japonica is listed as an endangered species. All individuals identified as F. japonica are of F. californica, so the current red list treats invasive non-native species as endangered. Reassessment of the conservation status of native species and an estimation of the impact of non-native species is required to better delineate these limpet species by genetic markers.  相似文献   

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