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1.
Blue tangs in Barbados exhibit three distinct social modes: territorial, schooling and wandering. We compared the mobility, foraging, aggression performed and received and the use of cleaning stations of adult blue tangs among modes and among habitats within a single fringing reef in Barbados. Evidence from observed switches during focal observations and multiple observations of tagged individuals indicate that fish are either territorial or non-territorial. Non-territorial fish formed schools and wandered. However, wandering can be used during solitary movements by fish in either type. Fish in the territorial mode, not previously described in adults of this species, restricted activity to a small area overlapping the territories of other tangs. They actively chased conspecifics and were chased mostly by damselfishes. They swam more slowly and fed at higher rates than other modes. Fish in the schooling mode ranged widely in compact, polarized groups of conspecifics, congeners and other species. They were not aggressive and were attacked mostly by damselfishes. They swam rapidly and fed at intermediate rates. Fish in the wanderer mode showed neither aggression nor association with other individuals. They swam rapidly, well above the substrate, fed little, were chased by conspecifics, ocean surgeonfish, A. bahianus, and damselfish and visited cleaning stations more often then other modes. All three modes were observed in all four main zones of the reef, and their behaviour changed quantitatively with habitat type. We suggest that territoriality reduces competition for algal food, schooling allows fish to overcome the food defence by damselfish, tangs and ocean surgeonfish, and wandering permits solitary movement over the reef to cleaning stations, feeding sites and other resources.  相似文献   

2.
Synopsis We hypothesized that blue tang, Acanthurus coeruleus, territories on sites with low biogenic structure would be larger than territories on sites with relatively high biogenic structure due to differences in the amount and distribution of resources. We tested this hypothesis by tracking blue tang over uncolonized pavement and reef crest, two habitat types at opposite ends of the habitat structure spectrum. We recorded density, feeding rates and aggression events in order to evaluate our findings in the context of a territory model and the ideal free distribution model. Territories of A. coeruleus averaged nearly four times larger on pavement sites than on reef crest sites. Conversely, densities of A. coeruleus were significantly lower on pavement sites. While there was no significant difference in the average rates of movement between habitats, average turning angles were significantly higher on reef crest. There were no significant differences in feeding rates between habitats, suggesting that higher territory sizes and lower densities may allow fish on uncolonized pavement to match resource acquisition of fish on reef crest. The insignificant difference of aggression encounters between habitats suggests that movement and density differences among habitats are not solely legacies of differential settlement.  相似文献   

3.
In order to test the effect of temperature variation on the growth of a common coral-reef fish, Acanthochromis polyacanthus, juveniles, sub-adults and adults were reared on either high or low food rations at temperatures corresponding to the long-term (14 year) minimum, average and maximum summer sea-surface temperatures (26, 28 and 31°C respectively) at Orpheus Island, Great Barrier Reef, Australia. Both temperature and food supply affected the growth of juvenile and adult A. polyacanthus. Individuals grew more on high food rations, but growth declined with increasing temperature. Importantly, at 31°C, the growth of juveniles and adults on the high food ration was nearly identical to growth on the low food ration. This indicates that the capacity for growth is severely limited at higher ocean temperatures that are predicted to become the average for Orpheus Island within the next 100 years as a result of rapid climate change. Communicated by Biology Editor Dr Mark McCormick  相似文献   

4.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.  相似文献   

5.
As the first step in understanding the molecular oscillation of the circa rhythms in the golden rabbitfish Siganus guttatus—a reef fish with a definite lunar-related rhythmicity—we cloned and sequenced a Period gene (rfPer). The rfPer gene contained an open reading frame that encodes a protein consisting of 1,452 amino acids; this protein is highly homologous to PER proteins of vertebrates including zebrafish. Phylogenetic analyses indicated that the rfPER protein is related to the zebrafish PER1 and PER4. The expression of rfPer mRNA in the whole brain, retina, and liver under light/dark (LD) conditions increased at 06:00 h and decreased at 18:00 h, suggesting that its robust circadian rhythm occurs in neural and peripheral tissues. When daily variation in the expression in rfPer mRNA in the whole brain and cultured pineal gland were examined under LD conditions, similar expression patterns of the gene were observed with an increase around dawn. Under constant light condition, the increased expression of rfPer mRNA in the whole brain disappeared around dawn. The present results demonstrate that rfPer is related to zPer4 and possibly zPer1. The present study is the first report on the Period gene from a marine fish.  相似文献   

6.
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.  相似文献   

7.
A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.  相似文献   

8.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.  相似文献   

9.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.  相似文献   

10.
Tropilaelaps mercedesae is a serious ectoparasite of Apis mellifera in China. The aim of this study was to investigate the infestation rates and intensity of T. mercedesae in A. mellifera in China, and to explore the relative importance of climate, district, management practices and beekeeper characteristics that are assumed to be associated with the intensity of T. mercedesae. Of the 410 participating apiaries, 379 apiaries were included in analyses of seasonal infestation rates and 352 apiaries were included in multivariable regression analysis. The highest infestation rate (86.3%) of T. mercedesae was encountered in autumn, followed by summer (66.5%), spring (17.2%) and winter (14.8%). In autumn, 28.9% (93) of the infested apiaries were in the north (including the northeast and northwest of China), 71.1% (229) were in the central and south (including east, southeast and southwest China), and 306 apiaries (82.9%) were co-infested by both T. mercedesae and Varroa. Multivariable regression analysis showed that geographical location, season, royal jelly collection and Varroa infestation were the factors that influence the intensity of T. mercedesae. The influence of beekeeper’s education, time of beekeeping, operation size, and hive migration on the intensity of T. mercedesa was not statistically significant. This study provided information about the establishment of the linkage of the environment and the parasite and could lead to better timing and methods of control.  相似文献   

11.
Ogataea parapolymorpha sp. n. (NRRL YB-1982, CBS 12304, type strain), the ascosporic state of Candida parapolymorpha, is described. The species appears homothallic, assimilates methanol as is typical of most Ogataea species and forms hat-shaped ascospores in asci that become deliquescent. O. parapolymorpha is closely related to Ogataea angusta and Ogataea polymorpha. The three species can be resolved from gene sequence analyses but are unresolved from fermentation and growth reactions that are typically used for yeast identification. On the basis of multiple isolates, O. angusta is known only from California, USA, in association with Drosophila and Aulacigaster flies, O. parapolymorpha is predominantly associated with insect frass from trees in the eastern USA but O. polymorpha has been isolated from various substrates in the USA, Brazil, Spain and Costa Rica.  相似文献   

12.
Capuchins rub particular plant materials into their pelage, a behavior for which most authors have proposed a medicinal function (Baker in American Journal of Primatology 38:263–270, 1996, Baker, M. (1998). Fur Rubbing as Evidence for Medicinal Plant Use by Capuchin Monkeys (Cebus capucinus): Ecological, Social, and Cognitive Aspects of the Behavior. Dissertation thesis. University of California Riverside; DeJoseph et al. in Journal of the American Academy of Dermatology 46:924–925, 2002). Individuals fur-rub solitarily or in groups, but researchers have not conducted studies to understand the differences. We investigated the link between the form of fur-rubbing and other social variables in 2 capuchin species. We supplied 2 captive groups —white-faced capuchins and tufted capuchins— with citrus fruit and onions and explored the behavioral processes and social aspects underlying the activity. We documented the occurrence, number of participants, and effect of recruitment behaviors in fur-rubbing subgroups. We investigated the role of kinship, affiliation, and dominance relationships in accounting for fur-rubbing groups. There is a significant difference in the form of fur-rubbing between white-faced and tufted capuchins. White-faced capuchins fur-rubbed mainly in subgroups and performed a particular behavior to recruit prospective participants, whereas tufted capuchins fur-rubbed mainly alone, and showed no particular motivation to be joined by other group members. White-faced capuchins could fur-rub together frequently, whatever their degree of kinship, affiliation, or dominance interval. In tufted capuchins, fur-rubbing appeared to be significantly affected by kinship and dominance.  相似文献   

13.
Understanding environmental drivers of black band disease (BBD), a virulent disease affecting corals worldwide, is critical to managing coral populations. Field monitoring studies have implicated seasonally elevated temperature and light as drivers of annual BBD outbreaks on the Great Barrier Reef, but do not distinguish their relative impacts. Here, we compare progression of BBD lesions on Montipora hispida among three controlled temperature (28.0, 29.0, 30.5°C) and two controlled light treatments (170, 440 μmol m−2 s−1) within normal seasonal ranges at the site. BBD progression rates were greatest (5.2 mm d−1) in the 30.5°C/high-light treatment and least (3.2 mm d−1) in the 28°C/low-light treatment. High light significantly enhanced BBD progression, whereas increases in disease progression under high temperatures were not statistically significant, identifying the greater role of light in driving BBD dynamics within the temperature range examined. Greater BBD progression during daytime compared with nighttime (by 2.2–3.6-fold across temperature and light treatments) corroborates our conclusion that light is the pre-eminent factor driving BBD progression at typical summer temperatures. Decreased photochemical efficiency of algal endosymbionts in the high-temperature/high-light treatments suggests that compromised health of the coral holobiont contributes to enhanced disease progression, highlighting the complexity of disease dynamics in host–pathogen systems responding to environmental changes.  相似文献   

14.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.  相似文献   

15.
Summary Interspecific facultative social parasitism is well known in ants and in bumble-bees, but it is rarer in wasps. This form of parasitism is traditionally considered to be an intermediate stage in the evolution of obligate interspecific parasitism, where the parasites are no longer able to nest alone. We report field and experimental observations of a newly discovered facultative parasitic relationship between two closely related free-living Polistes species: P. nimphus and P. dominulus. P. nimphus foundresses sometimes usurp the nests of the larger P. dominulus before worker emergence. The invading queen takes over the nest with abundant abdomen stroking on the nest surface and is accepted by workers if they emerge 6 or more days after usurpation. Morphometric comparisons show that the usurper species, though smaller than its victims, has morphological adaptations consisting of larger heads, mandibles and front femora relative to their body size that may give it an advantage during nest invasion. This strategy is likely to be taken only after the foundress loses her original nest because invading P. nimphus queens have lower reproductive success than they would have had on their own nest. Overall, we found that P. nimphus usurpers use strategies of invasion similar to those of two obligate parasites, suggesting that this may be an example of one of the pathways by which social parasitism evolved.Received 4 April 2003; revised 8 August 2003; accepted 14 September 2003.  相似文献   

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19.
Seol E  Jung Y  Lee J  Cho C  Kim T  Rhee Y  Lee S 《Plant cell reports》2008,27(7):1197-1206
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species.  相似文献   

20.
P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

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