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221.
222.
J. F. CRAIG 《Freshwater Biology》1975,5(2):183-187
The number of perch caught weekly in traps set in Slapton Ley, Devon has been considered. Five traps were laid in each of six regions during 1970 and 1971. The numbers caught in each region were averaged for eight lifts during 8 weeks and the logarithms of these numbers calculated. The figures obtained showed marked seasonal trends in the catch of the traps and these trends were consistent when both years were compared. If single traps were considered there was marked variability at one time which was attributed to differences in habitat. However, the combined data from each region did give a good comparison of the density of perch between regions. 相似文献
223.
EVI A. D. PAEMELAERE CRAIG GUYER F. STEPHEN DOBSON 《Biological journal of the Linnean Society. Linnean Society of London》2011,104(2):303-317
Female pattern polymorphisms (FPP) are striking, poorly understood, and a major challenge to evolutionary theory. We examined the evolution of FPP in anoline lizards in a phylogenetic context. Accordingly, we used comparative analyses that traced the evolution of female pattern polymorphism over historical time, and overlaid the historical pattern on the biogeographical distribution of current species. Comparative analyses used a maximum likelihood approach with variable rates of trait evolution. We found that, among almost 180 well‐described species, 52 exhibited FPP and most of these occurred on the Central American mainland. Pagel's λ = 0.644 indicated not only a moderately strong phylogenetic signal in FPP among 162 species with sound estimates of phylogeny, but also independent evolution. Their common ancestor was not polymorphic (0.003% likelihood of FPP), and there were at least 28 gains or losses of FPP during phylogenetic history. The geographical distribution of FPP indicates that, in the Caribbean islands, it has been present for almost 20 million years, and that parallel evolution of FPP has taken place during that time, including independent evolution on Cuba, Hispaniola, and Puerto Rico. Evidence of parallel evolution of FPP in anoles was fairly strong. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 303–317. 相似文献
224.
SILVIO ERLER HANS‐JÖRG FERENZ ROBIN F. A. MORITZ HANS‐HINRICH KAATZ 《Biological journal of the Linnean Society. Linnean Society of London》2010,99(2):296-305
In the present study, we present the full sequence of the mitochondrial genome of the African desert locust Schistocerca gregaria gregaria. The size of 15625 bp reported matches very well with mitochondrial genomes of other Orthopteriodea. The mitochondrial genome comprises 13 protein‐coding genes, two ribosomal RNAs and 22 t‐RNAs with two t‐RNA (trnD and trnK) rearrangements that are typical for the taxon Caelifera. We compared the sequence with 12 mitochondrial genes of Schistocerca gregaria flaviventris and Schistocerca americana and used some of these data to construct phylogenetic trees, which confirm the close relationship between the two subspecies S. g. flaviventris and S. g. gregaria. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 296–305. 相似文献
225.
SARGENT ROBERT CRAIG; RUSH VICTOR N.; WISENDEN BRIAN D.; YAN HONG Y. 《Integrative and comparative biology》1998,38(1):82-96
SYNOPSIS. Sexual selection theory predicts a coevolution betweenmale sexual ornamentation and female preference. The implicationof this prediction for sensory ecology is that there shouldbe a tight coupling between the physiology of male signal productionand the physiology of female signal reception. Indicator modelsof sexual selection predict that male ornamentation is correlatedwith male condition, and that female preference is correlatedwith male ornamentation. Indicator models of sexual selectionhave a conceptual overlap with resource acquisition and investmentmodels of behavioral ecology. Empirical studies with fishes,particularlywith guppies (Poecilia reticulata) and threespinesticklebacks (Gasterosteus aculeatus), suggest a strong connectionbetween acquired resources, male condition, male ornamentation,male courtship, and female preference. 相似文献
226.
We report the identification of intraspecific sequence variation in the Atlantic salmon (Salmo salar) growth hormone 1 gene. Rapid and inexpensive assays for polymorphism detection were developed for 10 sites. Five of the assays detected single nucleotide polymorphisms (SNPs) using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analyses, and five were indel polymorphisms, detected using fragment length analyses. The average within population frequency of the most common allele varied from 0.52 to 0.90, and the average within population heterozygosity varied from 0.02 to 0.37 in seven European salmon populations. 相似文献
227.
A reinvestigation by optical and electron microscopy of sevenplant species, native to New Zealand, howed no bacteria in anyof the plant cells or secretions claimed to contain them. Itis concluded that if these symbioses sometimes occur, they donot constitute a general feature. No previous work has described the presence of micro-organismsin the bud secretions of Vitex lucens, but a large populationof bacteria and fungi were observed here, during the courseof this study. 相似文献
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JOSEPH P. VALENTINE DAVID B. TARBATH STEWART D. FRUSHER CRAIG N. MUNDY COLIN D. BUXTON 《Austral ecology》2010,35(7):806-817
It is increasingly recognized that fisheries must take the broader ecosystem into account for sustainable management of marine systems, requiring an understanding of the interaction between fished species and other organisms. This study uses a correlative approach to investigate potential interactions between benthic organisms and Haliotis rubra, a dominant herbivore that is the subject of a large and valuable commercial fishery in south‐eastern Australia. Specific emphasis was placed on understanding associations between H. rubra and understorey organisms, because particular understorey algae (crustose coralline algae) provide critical habitat for H. rubra larval recruitment and juvenile ecology. Broad‐scale surveys along the 6–8 m depth contour (the depth range where H. rubra fishing activity is intense) were conducted across four regions (separated by 104?105 m), including at least 10 sites (separated by 102?103 m) within each region. Positive correlations between H. rubra and crustose coralline algae were found, while negative correlations were observed between H. rubra and sessile invertebrates and understorey algae. While significant, these associations were weak and H. rubra abundance generally only explained a small proportion of the variability in the abundance of understorey organisms (r2 0.02–0.30). H. rubra abundance also had a minor influence on community‐level understorey patterns in comparison with differences in community structure attributable to regional variation. Patterns of H. rubra abundance and benthic community structure were also examined in relation to depth at a restricted number of sites. At sites where differences in understorey groups were evident, H. rubra abundance also varied significantly, highlighting the issue of confounding when contrasting patterns of understorey abundance using a correlative approach. Further manipulative experiments are required to confirm causal relationships; however, the available correlative evidence suggests limited ecosystem effects of H. rubra depletion at the scale of individual reefs. 相似文献