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41.
Aim Ecologists seeking to describe patterns at ever larger scales require compilations of data on the global abundance and distribution of species. Comparable compilations of biological data are needed to elucidate the mechanisms behind these patterns, but have received far less attention. We assess the availability of biological data across an entire assemblage: the well‐documented demersal marine fauna of the United Kingdom. We also test whether data availability for a species depends on its taxonomic group, maximum body size, the number of times it has been recorded in a global biogeographic database, or its commercial and conservation importance. Location Seas of the United Kingdom. Methods We defined a demersal marine fauna of 973 species from 15 phyla and 40 classes using five extensive surveys around the British Isles. We then quantified the availability of data on eight key biological traits (termed biological knowledge) for each species from online databases. Relationships between biological knowledge and our predictors were tested with generalized linear models. Results Full data on eight fundamental biological traits exist for only 9% (n= 88) of the UK demersal marine fauna, and 20% of species completely lack data. Clear trends in our knowledge exist: fish (median biological knowledge score = six traits) are much better known than invertebrates (one trait). Biological knowledge increases with biogeographic knowledge and (to a lesser extent) with body size, and is greater in species that are commercially exploited or of conservation concern. Main conclusions Our analysis reveals deep ignorance of the basic biology of a well‐studied fauna, highlighting the need for far greater efforts to compile biological trait data. Clear biases in our knowledge, relating to how well sampled or ‘important’ species are suggests that caution is required in extrapolating small subsets of biologically well‐known species to ecosystem‐level studies.  相似文献   
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Abstract: Growth periodicity is a phenomenon occurring in fossil and modern corals. The most apparent feature is growth banding, and environmental changes are broadly accepted as controls on this phenomenon. If environment controls the growth, then all corallites within a colony should repeat the same growth pattern, as individuals are clones and must have shared the same environment. A study on several species of Alveolitidae (Anthozoa, Tabulata) from the Late Devonian (Early Frasnian) of the Holy Cross Mountains (Poland) shows that the growth pattern varies between neighbouring individuals within the same corallum. This contradicts observations of closely related Favositida as demonstrated on Pachyfavosites sp. from the Givetian of Avesnois, France, where neighbouring individuals repeat the same pattern. Therefore, environmental control on growth rhythm in Alveolitidae can be excluded; the causes of differences between individuals remain unknown.  相似文献   
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The European mink is a critically endangered mustelid species of conservation concern throughout Europe. Several conservation interventions have been implemented in recent years, supported by both national and European governments. However, knowledge about the natural history of the European mink is scarce and localized to a few specific areas. From 2007 to 2009, we studied mink activity patterns, home range sizes, and macrohabitats of mink home ranges based on 28 radio-tracked European mink (10 adult females, 11 adult males, 3 young females, and 4 young males) in the Foral Community of Navarre (northern Spain), in the Arga and Aragón rivers. We also provide insights on the spatial organization of the species. European mink presented a stable, mainly nocturnal and crepuscular activity pattern and required between 15 and 75 ha of fluvial habitats to establish their home ranges, which were also quite stable throughout the year. There were great differences between adult females and adult males, the latter having home ranges five times larger. In addition, whereas adult females mainly settled in lagoons and small tributaries, males also used to a large extent the main river sections. European mink presented a polygynous mating system, where males were territorial and encompassed several female home ranges within their home ranges. Lagoons and similar structures should be preserved and favored in management strategies, and tributaries maintained in good condition, as female requirements should be prioritized in plans to improve the general habitat quality for the species. Any conservation plan aimed at the improvement or recovery of European mink populations through habitat management should consider management blocks of at least 15 ha per each potential breeding female.  相似文献   
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Historical ecology of the Raja Ampat Archipelago, Papua Province, Indonesia   总被引:1,自引:0,他引:1  
This work presents a review of the status of marine resources of the Raja Ampat Archipelago, Papua Province, Indonesia, based on narratives of early European expeditions in various museums and libraries in Europe, Canada, and local archives in Papua. More than 500 pertinent documents on the study area were identified and located in various European museums and at the University of British Columbia library. About half of these were scanned (25,000 pages), which yielded the equivalent of 900 pages of text (or 4% of the total number of pages scanned) with observations on abundance and impact of the human population on the marine ecosystem within 2 degrees North and 2 degrees South between 127 degrees and 132 degrees East. In general, these observations, which spanned the period from 1810 to the present, suggest a decrease in the perceived occurrences of turtles, fish, and invertebrates; perceived abundance of turtles, fish, and algae; percieved subsistence exploitation of marine resources; and an increase in perceived commercial exploitation of marine resources. We conclude with a discussion of the problems and potential of contents analysis, and its use in the historical reconstruction of broad biodiversity trends.  相似文献   
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Abstract DNA fragments representatives of ndv A and ndv B have been used as probes against genomic DNAs from different Rhizobium and Bradyrhizobium species. ndv A and ndv B homologues were found in all species, indicating extensive conservation of these genes. All Rhizobium species show chromosomal localization of ndv A and ndv B homologues.  相似文献   
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The Rhizobium leguminosarum bv trifolii exoB gene has been isolated by heterologous complementation of an exoB mutant of R. meliloti. We have cloned a chromosomal DNA fragment from the R. leguminosarum bv trifolii genome that contains an open reading frame of 981 bp showing 80% identity at the amino acid level to the UDP-glucose 4-epimerase of R. meliloti. This enzyme produces UDP-galactose, the donor of galactosyl residues for the lipid-linked oligosaccharide repeat units of various heteropolysaccharides of rhizobia. An R. leguminosarum bv trifoliiexoB disruption mutant differed from the wild type in the structure of both the acidic exopolysaccharide and the lipopolysaccharide. The acidic exopolysaccharide made by our wild-type strain is similar to the Type 2 exopolysaccharide made by other R. leguminosarum bv trifolii wild types. The exopolysaccharide made by the exoB mutant lacked the galactose residue and the substitutions attached to it. The exoB mutant induced the development of abnormal root nodules and was almost completely unable to invade plant cells. Our results stress the importance of exoB in the Rhizobium-plant interaction.  相似文献   
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