关键词： LAS   SEDIMENT   TOXICITY   MUSSELS  

摘要： The toxicity of LAS on aquatic animals has been evaluated in particular relation to its concentration in water, although it is well known that sediments play an important role as repositories and sources of many contaminants, including surfactants. The aim of this study was to evaluate the effects of sediment-sorbed LAS on the marine mussel Mytilus galloprovincialis exposed to sediments drugged with 132 mg/kg dry weight of LAS mixtures. Four experiments were performed and some physiological parameters (filtration, oxygen uptake, nitrogen excretion) were measured on control and treated animals. In order to study uptake and release of sediment-sorbed LAS by mussels, quantification of weight, percentage of organic matter, LAS concentration and LAS homologue distribution on faeces were determined. Results showed no significant differences in physiological responses of treated mussels compared to controls, and the absence of a toxic action of LAS contaminated sediments. Moreover one notable aspect was that higher LAS concentrations were found in faeces than in uningested sediments recovered from water. This fact is tentatively explained either as the result of decreased desorption in the mussel intestinal tract with respect to circulating water, or as enrichment in fine particles by mussel filter feeding activity.

关键词： BARK FAUNA   COLPODEA   COLPODIDAE   HAWAIIAN ARCHIPELAGO   INFRACILIATURE   METROSIDEROS POLYMORPHA  

摘要： Corticocolpoda kaneshiroae n. g., n. sp. was discovered in the bark of Ohia trees (Metrosideros polymorpha) from the Hawaiian Archipelago. Its morphology and infraciliature were studied in live cells, with the scanning electron microscope, as well as in specimens impregnated with protargol, silver nitrate, and silver carbonate. The new genus, Corticocolpoda, belongs to the family Colpodidae and is unique in having a left oral ciliary field (polykinetid) composed of 13-20 equidistantly spaced, paired rows of monokinetids. The new species, C. kaneshiroae, measures 100-300 x 60-250 mu m and has a huge vestibulum used to capture large food items, mainly other ciliates. The oral ciliary fields are within the vestibulum and of equal length;the right field is a paroral membrane composed of a single row of dikinetids. Several micronuclei are attached to the ellipsoid macronucleus. The mucocysts are inconspicuous and arranged around the somatic dikinetids. The resting cyst is globular and has a 1-2 mu m thin, firm, yellowish inner wall and a 20-mu m-thick, fragile, hyaline outer wall. Convergent evolutionary paths and a possible polyphyly of the Colpodidae are discussed. An improved key to the genera of the family Colpodidae is provided. Twenty-three species of ciliates and one flagellate (Hemimastix amphikineta), which occurred together with C. kaneshiroae, are new for the fauna of Hawaii and listed in the ecology section.

关键词： DWARF BAMBOO   REGENERATION   SASA   SHADE-TOLERANCE   ZOOCHORE  

摘要： The effects of dwarf bamboos (Sasa spp.) on the regeneration of trees in a natural hardwood forest were studied by analysing the spatial dispersion of seedlings and saplings of anemochores (Acer palmatum var. matsumurae, Fraxinus lanuginosa, and Carpinus laxiflora) and zoochores (Quercus mongolica var. grosseserrata and Q. serrata). Relative photosynthetic photon flux density at 10 cm above ground was significantly correlated with the coverage of dwarf bamboos (r=0.661, P<0.001). Seedlings were abundant and were randomly distributed in the anemochores, other than the shade-intolerant species C. laxiflora which was significantly more sparse in sites with dense Sasa than in sites where Sasa was rare. Distribution of saplings was also random in the shade-tolerant anemochores A. palmatum var. matsumurae and F. lanuginosa but aggregated in sites with sparse Sasa in the shade-intolerant anemochore C. laxiflora. In contrast to the anemochores, seedlings of zoochores were very few and were distributed in sites with sparse Sasa. Saplings were also aggregated and negatively correlated with Sasa cover in the shade-intolerant species Q. serrata and the tolerant species Q. mongolica var. grosseserrata. The acorns put on the forest floor in a site with dense Sasa were quickly removed by small rodents such as Apodemus speciosus and A. argenteus. Trap census of rodents revealed that those mammals prefer the dense Sasa habitat to the sparse Sasa habitat. This suggests that the dwarf bamboos strongly affect the regeneration of zoochorous trees not only by shading the seedlings but also by providing habitats to acorn-feeding small mammals.

关键词： RHIZOPHAGUS-GRANDIS   DENDROCTONUS-MICANS   COLEOPTERA   KAIROMONE   FLIGHT   PREDATOR   SCOLYTIDAE   RHIZOPHAGIDAE   VISUAL ORIENTATION   PICEA-ABIES   OLFACTORY   BARK BEETLE  

摘要： Insects apparently responding to the visual stimulus offered by a tree or other object may also be responding to the variety of physical effects caused by the obstruction, including turbulence, a reduction in wind velocity and eddies. The relative importance of prey odour associated with the bark beetle Dendroctonus micans (Kugelann) (Scolytidae), prey-host-tree odour, silhouette, and physical barrier to the wind, in the orientation and landing behaviour of a predatory beetle, Rhizophagus grandis Gyllenhall (Rhizophagidae), were investigated. *** responded very positively to the frass of its prey when presented on a 'tree' but not to the same quantity of frass presented alone. Frass on black plastic uPVC pipes was significantly more attractive than frass on real host tree logs, suggesting that host-tree volatiles do not enhance the attractiveness of prey frass. The beetles responded to 'transparent' Mylar three-dimensional cylinders in the same way as they did to the black plastic pipes. Beetles were also tested with frass and two-dimensional stimuli offering a visual stimulus or physical barrier alone or in combination. Frass with a two-dimensional visual stimulus was no better than frass alone: few insects landed. Significantly more insects were attracted to the same two-dimensional visual stimulus with a hidden upwind barrier producing turbulence, but a similar number were attracted to the frass in front of a hidden barrier alone. As many plants are similar in size to the logs used in these experiments, comparable effects might influence the behaviour of other phytophagous insects, their predators and parasitoids.

关键词： MYOGLOBIN   AMINO ACID SEQUENCE   LIOLOPHURA (MOLLUSK)   PHYLOGENETIC TREE  

摘要： Myoglobin was isolated from the radular muscle of the chiton Liolophura japonica, a primitive archigastropodic mollusc. Liolophura contains three monomeric myoglobins (I, II, and III), and the complete amino acid sequence of myoglobin I has been determined. It is composed of 145 amino acid residues, and the molecular mass was calculated to be 16,070 D. The E7 distal histidine, which is replaced by valine or glutamine in several molluscan globins, is conserved in Liolophura myoglobin. The autoxidation rate at physiological conditions indicated that Liolophura oxymyoglobin is fairly stable when compared with other molluscan myoglobins. The amino acid sequence of Liolophura myoglobin shows low homology (11-21%) with molluscan dimeric myoglobins and hemoglobins, but shows higher homology (26-29%) with monomeric myoglobins from the gastropodic molluscs Aplysia, Dolabella, and Bursatella. A phylogenetic tree was constructed from 19 molluscan globin sequences. The tree separated them into two distinct clusters, a cluster for muscle myoglobins and a cluster for erythrocyte or gill hemoglobins. The myoglobin cluster is divided further into two subclusters, corresponding to monomeric and dimeric myoglobins, respectively. Liolophura myoglobin was placed on the branch of monomeric myoglobin lineage, showing that it diverged earlier from other monomeric myoglobins. The hemoglobin cluster is also divided into two subclusters. One cluster contains homodimeric, heterodimeric, tetrameric, and didomain chains of erythrocyte hemoglobins of the blood clams Anadara, Scapharca, and Barbatia. Of special interest is the other subcluster. It consists of three hemoglobin chains derived from the bacterial symbiont-harboring clams Calyptogena and Lucina, in which hemoglobins are supposed to play an important role in maintaining the symbiosis with sulfide bacteria.

关键词： AUSTRALIA   SMALL VERTEBRATES   MALLEE WOODLANDS   FIRE   SERAL RESPONSES  

摘要： The short- and long-term post-fire response patterns of small mammals, reptiles and amphibians inhabiting mallee woodlands and heathlands in temperate Australia are reviewed with respect to species' life history parameters in a search for unifying trends. Pyric response patterns of small mammal species are closely lied to their shelter, food and breeding requirements. There is a trend of increased specificity and reduced flexibility in life history traits concomitant with increased impact of fire and later post-fire recolonization. For reptiles there appears to be a strong relationship between the shelter and foraging requirements of species and their abundance in various successional states. The high incidence of burrowing in the mallee/heath amphibian fauna imparts considerable resilience to fire, and most species' abundance and distribution patterns seem more closely linked to moisture regimes than to fire per se. The high degree of consistency between species' post-fire response patterns and their life history parameters points to the feasibility of developing a model to predict the impact of fire on small vertebrates. Such a model is currently being developed

关键词： BANDICOOT   BETAINE   ECHIDNA   ERYTHROCYTES   H-1 NMR   KOALA   LITTLE PENGUIN   P-31 NMP   PLASMA   TAMMAR WALLABY   TASMANIAN DEVIL   TAURINE   TREE KANGAROO   WOMBAT  

摘要： H-1 and P-32 NMR spectra were acquired from the whole plasma and ultrafiltrates of erythrocytes (RBC) from eight Australian native animals. Various metabolites contained in the samples were identified from their NMR spectra and their concentrations were determined where possible. The key observations were as follows. (1) High lysine concentrations in the RBC from Tammar wallaby (approximately 8 mmol/(L RBC)) were confirmed. (2) A resonance at delta 3.17 in the H-1 spin-echo NMR spectrum of koala RBC was reassigned to the N+-(CH3)3 of betaine and not to ergothioneine as previously claimed. (3) A high concentration (approximately 10 mmol/(L RBC)) of taurine was observed in the RBC from 'little' penguin. (4) The lack of ATP in the RBC of echidna, reported previously on the basis of standard biochemical assays, was confirmed directly by NMR spectroscopy. (5) The highest ergothioneine concentrations in the RBC of the eight species of animal were in the wombat (1.76 mmol/(L RBC)).

关键词： 实验动物   动物模型  

摘要： 自从1981年吴小闲等人将我国的野生树(鼠包)(Tupaia belangeri chinensis)引进实验室饲养繁殖以来,许多研究者把这种新的实验动物用于医学科研,并取得进展。树(鼠包)为小型灵长类动物,其形态、生理机能和生化代谢方面与人相似,作为动物模型可能更接近于人类情况,实验结果容易推广到人。目前,树(鼠包)在甲、乙型肝炎和睡眠生理研究上有重要用途,树(鼠包)还被用作化学致癌、黄曲霉素致肝癌以及人疱疹病毒感染的实验研究,树(鼠包)还被广泛地应用于生态学、形态学、神经生理学、寄生虫学、

摘要： Comparative intestine lengths of 15 Southern African savanna rodents and insectivores are presented. Differences in relative intestine length (ratio between hind gut length to head/body length) between seasons were significant in Aethomys chrysophilus. In various species, breeding females, with their increased energy requirement, had hind gut lengths that were well above average. These females also accounted for the differences between sexes which were significant in two species (Aethomys chrysophilus and A. namaquensis). Within species no correlation was found between relative intestine length and body size (length and weight) of the animals. Between species the correlation was significant and the larger species had relatively longer intestines. Three groups can be distinguished according to the different feeding types of the species. The omnivorous Praomys natalensis has by far the longest intestine. It is followed by a group of species that can be considered as granivore/herbivore. The species that are partly or predominantly insectivorous have the shortest intestine. The results of the field study are found to be in agreement with reports from laboratory experiments concerning adaptations of intestine length to different environmental situations.