European checkerspots (Melitaeini: Lepidoptera,Nymphalidae) are not aposematic – the point of view of great tits (Parus major)

相似文献   

Degradation of hydrocarbons and their derivatives by a microbial association based on Canadian pondweed

The degrading action of an aquatic plant-microbial association on the base of Canadian pondweed (Elodea canadensis) and its components (sterilized plant and two periphytonic strains, Pseudomonas fluorescens E1-2.1 and Brevundimonas diminuta E1-3.1) on crude oil, the water-soluble crude oil fraction, and individual test compounds (phenol, toluene, benzene, decalin, and naphthalene) was studied. It was found that the native association had a wider range and higher degree of degrading activity than individual species. Bacterial strains were significantly more active only towards naphthalene. The ability of the sterilized plant to degrade crude oil and phenol was no less than that of microorganisms and much more for toluene. Enzymatic activity towards the pollutants studied was found in E. canadensis exudates and buffer extracts of its cells.     

ONTOGENETIC NICHE SHIFT IN THE BRACHIOPOD TEREBRATALIA TRANSVERSA: RELATIONSHIP BETWEEN THE LOSS OF ROTATION ABILITY AND ALLOMETRIC GROWTH

Abstract: Many articulated brachiopods experience marked life habit variations during ontogeny because they experience their fluid environment at successively higher Reynolds numbers, and they can change the configuration of their inhalant and exhalant flows as body size increases. We show that the extant brachiopod Terebratalia transversa undergoes a substantial ontogenetic change in reorientation governed by rotation around the pedicle. T. transversa′s reorientation angle (maximum ability to rotate on the pedicle) decreases during ontogeny, from 180 degrees in juveniles to 10–20 degrees in individuals exceeding 5 mm, to complete cessation of rotation in individuals larger than 10 mm. Rotation ability is substantially reduced after T. transversa achieves the adult lophophore configuration and preferred orientation with respect to ambient water currents at a length of 2.5–5 mm. We hypothesize that the rotation angle of T. transversa is determined mainly by the position of ventral and dorsal points of attachment of dorsal pedicle muscles relative to the pedicle. T. transversa shows a close correlation between the ontogenetic change in reorientation angle and ontogeny of morphological traits that are related to points of attachment of dorsal pedicle muscles, although other morphological features can also limit rotation in the adult stage. The major morphological change in cardinalia shape and the observed reduction of rotation affect individuals 2.5–10 mm in length. The position of ventral insertions of dorsal pedicle muscles remains constant, but contraction of dorsal pedicle muscles is functionally handicapped because dorsal insertions shift away from the valve midline, rise above the dorsal valve floor, and become limited by a wide cardinal process early in ontogeny (<5 mm). The rate of increase of cardinal process width and of distance between dorsal pedicle muscle scars substantially decreases in the subadult stage (5–10 mm), and most of the cardinalia shell traits grow nearly isometrically in the adult stage (>10 mm). T. transversa attains smaller shell length in crevices than on exposed substrates. The proportion of small‐sized individuals and population density is lower on exposed substrates than in crevices, indicating higher juvenile mortality on substrates prone to grazing and physical disturbance. The loss of reorientation ability can be a consequence of morphological changes that strengthen substrate attachment and maximize protection against biotic or physical disturbance (1) by minimizing torques around the pedicle axis and/or (2) by shifting energy investments into attachment strength at the expense of the cost involved in reorientation.     

Efficiency of alfalfa and reed in the phytoremediation of hydrocarbon polluted soil

The efficacy of plants as means of decontaminating hydrocarbon-polluted soil has been studied. Ditch reed (Phragmites australis) and alfalfa (Medicago sativa) markedly intensified processes of pollutant destruction, the effect being particularly pronounced in the case of polycyclic aromatic hydrocarbons (PAHs). Comparative analysis of microflora in soils (including those devoid of plants and rhizosphere) demonstrated that, in addition to preventing the pollutant-induced decrease in the amount of heterotrophic microorganisms, the plants stimulated their development, significantly increasing the population of destructors. Effects of plants on major physiological groups of soil microorganisms under conditions of pollution were ambiguous. The rhizosphere consortium of alfalfa was less susceptible to effects of pollutants than that of reed.     

Degradation of mineral oil by Acinetobacter calcoaceticus strain

The Acinetobacter calcoaceticus strain TM-31 has been isolated from a microbial assemblage of a pilot plant purifying waste water polluted with mineral oil. This strain is capable of efficient degradation of components of mineral oil (alkanes, isoalkanes, and alkyl residues of the naphthene and arene fraction. The strain bears stably inherited plasmids of sizes 120, 9, and 8 kb, which can be transferred into plasmid-free cells of the parental strain and into bacteria of the genus Pseudomonas and ensure the degradation of hexadecane and mineral oil.     

Diversity and ecology of algae from the Nahal Qishon river,northern Israel

In 59 samples of periphyton and phytoplankton collected in 2002 - 2003 from the Nahal Qishon (Qishon River), northern Israel, we found 178 species from seven divisions of algae and cyanoprocaryotes. Diatoms, clorophytes, and cyanoprocaryotes prevail. Nitzschia and Navicula (Bacillariophyta) are the most abundant. Most of the species are cosmopolitan or widespread, except Lagynion janei (Chrysophyta), which is endemic for the Mediterranean Realm. About 17% of species (26) are new for Israel and five of them represent the first recorded genera: Crinalium endophyticum Crow, Actinocyclus normanii (Gregory) Hustedt, Rhizoclonium hieroglyphicum (Agardh) Kütz (Chlorophyta), Lagynion janei Bourelly, and Stylococcus aureus Chodat. Most of them come from a rare riverine assemblage with red alga Audouinella pygmea, as well as from the estuarine assemblage. Alkaliphiles predominate among the indicators of acidity, with few acidophiles confined to the communities under the impact of industrial wastes. Among the indicators of salinity, most numerous are the oligohalobien-indifferents and species adapted to a moderate salinity level. The relative species richness of ecological groups and the indices of saprobity are correlated with changes in conductivity, pH, and N-nitrate concentration. Indicators of organic pollution fall in the range of betameso- to alfamesosaprobic self-purification grades. Our studies show ecological significance of the Nahal Qishon as a model for a strongly disturbed aquatic ecosystem in the coastal zone of eastern Mediterranean.     

Respiratory activity of bacteria Acinetobacter calcoaceticus TM-31 during assimilation of alkane hydrocarbons

The respiratory activity of Acinetobacter calcoaceticus TM-31 with resect to alkane hydrocarbons was studied. The dynamics of oxygen consumption by the cells while assimilating n-hexadecane was assayed by a modified technique using an oxygen electrode. The dependence of cell respiratory activity on the amount of n-hexadecane within the concentration range of 0.03-0.66% was determined. It was demonstrated that the cells also displayed respiratory activity towards other medium-chain n-alkanes: hexane, octane, decane, tridecane, and heptadecane. Thus, we demonstrated the possibility of determining alkanes by measuring the respiratory activities of microorganisms.     

Study of microbial degradation of nonionic surface-active agents in designing technologies for purifying waste water

Studies of degradation of non-ionic surfactants (NISA) in a model purification plant of an original design demonstrated an high rate and depth of degradation processes compared with periodic cultivation of free or immobilized degrading strains. A virtually complete primary degradation (99-99.5%), with destruction of the oxyethyl moiety of the molecule, was observed. In addition, NISA molecules were degraded to a greater extent, including considerable degradation of the hydrocarbon radical, partial degradation of aromatic structures in Neonol, and utilization of biologically "unyielding" fractions of commercial NISA preparations: polyethylene glycol (PEG) and long-chain fractions of polymer homologues.     

Oil-oxidizing potential of associative rhizobacteria of the genus Azospirillum

The oil-oxidizing potential of associative rhizobacteria of the genus Azospirillum was studied under laboratory conditions. After screening, A. brasilense strain SR80 was chosen for further investigation. The strain was capable of degrading 56.5% of crude oil (added in a concentration of 1%) over 14 days in a medium containing malate as an additional source of carbon and energy. Studies of associative properties showed that the strain had positive chemotaxis to wheat root exudates, colonized wheat roots, and produced indolyl-3-acetic acid. The synthesis of indolyl-3-acetic acid was not inhibited by oil. Under hydroponic conditions, crude oil stimulated growth of A. brasilense SR80, which promoted development of the wheat root system in the presence of oil and enhanced the level of oil degradation by the plant-microbial association.     

Changes in fatty acids contents and growth characteristics in transformed oilseed rape (Brassica napus)

Spring oilseed rapeBrassica napus L. ssp.oleifera cv. HM-81 was transformed with T_L-DNA of the Ri plasmid of the agropine strainAgrobacterium rhizogenes 15834. Selfed progenies (R₂ and R₃ generations) were studied for changes in values of growth characteristics and fatty acids contents. Transformants are ‘homozygous’ for T_L-DNA. Both generations of transformants differed significantly from the nontransformed control plants in reduced length, lower number of pods per plant, lower total mass of seeds and the higher number of branches. The contents of palmitic, linoleic and linolenic acids were significantly higher in transformants when compared with the control. On the contrary, the contents of both stearic and oleic acids were in most of transformants significantly lower. Only traces of erucic acid (less than 0.05 % ) were found, both in transformed and nontransformed plants.