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71.
Sigal Lahav Victoria Soroker Robert K. Vander Meer Abraham Hefetz 《Behavioral ecology and sociobiology》1998,43(3):203-212
This study compares two basic models for the origin and maintenance of colony gestalt odor in the polygynous ant species
Cataglyphis niger. In the first model, queens are centers of de novo biosynthesis and distribution of recognition odors (“queen-centered” model);
in the second, colony odors are primarily synthesized and distributed by workers (“worker-centered” model). We tested the
behavioral patterns that are predicted from each model, and verified by biochemical means the distributional directionality
of these signals. Encounters between nestmates originating from split colonies were as amicable as between nestmates from
non-split colonies; queenless ants were as aggressive as their queenright nestmates, and both were equally aggressed by alien
ants. These results indicate that queens have little impact on the recognition system of this species, and lend credence to
the worker-centered model. The queen-centered model predicts that unique queen substances should be produced in appreciable
quantities and that, in this respect, queens should be more metabolically active than workers. Analysis of the chemical composition
of postpharyngeal glands (PPGs) or cuticular extracts of queens and workers revealed high similarity. Quantitatively, queens
possessed significantly greater amounts of hydrocarbons in the PPG than workers, but the amount on the thoracic epicuticle
was the same. Queens, however, possess a lower hydrocarbon biosynthesis capability than workers. The biochemical evidence
thus refutes the queen-centered model and supports a worker-centered model. To elucidate the directionality of cue distribution,
we investigated exchange of hydrocarbons between the castes in dyadic or group encounters in which selective participants
were prelabeled. Queens tended to receive more and give less PPG content, whereas transfer to the epicuticle was low and similar
in all encounters, as predicted from the worker-centered hypothesis. In the group encounters, workers transferred, in most
cases, more hydrocarbons to the queen than to a worker. This slight preference for the queen is presumably amplified in a
whole colony and can explain their copious PPG content. We hypothesize that preferential transfer to the queen may reflect
selection to maintain her individual odor as close to the average colony odor as possible.
Received: 4 November 1997 / Accepted after revision: 5 February 1998 相似文献
72.
Hydrocarbon contamination of a terrestrial ecosystem:
the case of Oshire-2 oil spill in Niger Delta,Nigeria 总被引:1,自引:0,他引:1
An oil-impacted site at Oshire-2 in Niger Delta (Nigeria) was delimited by reconnaissance. Surface and subsurface soils were
analyzed for total extractable hydrocarbon content and some physicochemical characteristics. The oil-impacted soils had a
mean hydrocarbon content of 1.99 × 103 mg/kg (no overlap in Standard Error at 95% Confidence Limit) and were characterized by an isohyperthermic temperature regime
>22°C, high moisture content, high acidity (low soil-pH) and low electrical conductivity. The intense infusion of degradable
hydrocarbons at the site must have stimulated aerobic and anaerobic microbial metabolism and so, as oxygen became limiting,
utilization of alternate electron acceptors produced an increasingly reducing environment. 相似文献
73.
Pollution in the marine protected area of North Sporades Islands was investigated in July 1997. Salinity, temperature, dissolved oxygen, dissolved inorganic nutrients, organic carbon, hydrocarbons as well as dissolved and particulate trace metals were determined at 15 offshore and coastal stations. Dissolved organic carbon and inorganic nutrient concentrations indicate the mesotrophic character of the investigated waters. The dissolved forms of nitrogen were slightly higher at coastal stations. Dissolved and particulate Cu, Zn and Ni, were higher in coastal stations, whereas concentrations of Pb were generally low and likely of atmospheric origin. Dissolved/Dispersed petroleum hydrocarbons (DDPH) were close to detection limits at all stations. Temperature and salinity vertical profiles, nutrient and trace metal concentrations revealed the presence of a slight influence of the Black Sea water coming from Dardanelles straits. 相似文献
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