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Chalcalburnus tarichi is an anadromous cyprinid fish that has adapted to extreme conditions (salinity 22 ‰, pH 9.8 and alkalinity 153 mEq × l?1) in Lake Van in eastern Turkey. Changes in immunoreactivity of Na+/K+-ATPase in gill tissue and osmolarity and ion levels in plasma were investigated in C. tarichi during reproductive migration. Physicochemical characteristics and ion levels in Lake Van were high compared freshwater. Plasma osmolality and plasma ion concentrations ([Na+], [K+] and [Cl?]) increased after transfer from freshwater to Lake Van. The mitochondria-rich (MR) cells of the gill were stained in both filament and lamellar epithelia of C. tarichi by immunocytochemistry with a specific antiserum for Na+/K+-ATPase in river fish samples. Density and area of MR cells were decreased in lake-adapted fishes. These results indicated that freshwater acclimation capacity is correlated with the size and distribution of MR cells in C. tarichi, in contrast to many teleost fishes.  相似文献   

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In this study, acetylcholinesterase (AChE; EC 3.1.1.7) was purified from plasma and erythrocytes in the Lake Van fish (Chalcalburnus tarichii P.1811) by affinity chromatography. Enzymatic activity was spectrophotometrically measured according to Ellman's method, at 412 nm. Then, the optimal pH and temperature of the enzyme was determined. According to the results, the optimal pH and the optimum temperature were 8.0 and 25 degrees C, respectively. In order to control the purification of the enzyme, sodium dodecyl-sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was done. SDS-PAGE showed a single band for enzyme. The purification rates for plasma AChE and erythrocyte AChE are 3251.6 and 8500, respectively.  相似文献   

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Russian Journal of Bioorganic Chemistry - A proteomic analysis of the venom of males and females of the Naja kaouthia monocled cobra specimens kept in captivity was carried out. Using the amino...  相似文献   

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Concentrations of chlorinated hydrocarbons and their derivatives in the organs of spotted seals captured in the Sea of Japan are determined. Isomers of hexachlorocyclohexane (HCCH) and metabolites of dichlorodiphenyltrihlormetilmetan (DDT) are detected in all the studied animals in all the samples, but the highest concentrations are found in adipose tissue, which is a peculiar depot in which toxins are accumulated. Substantial differences in the extent of damage by toxins are discovered in seals of different populations, which is due to different intensities in the action of technogenic load on separate water areas. The level of accumulation of lipophilic xenobiotics in the tissues and organs of spotted seals of the Sea of Japan, particularly from the Peter the Great Bay (PGB), turn out to be very high (several orders of magnitude higher than that in spotted seals from the Tatar Strait and the coastal region of Hokkaido). Such a high level of chlorinated organic pesticides (COPs) has not yet been detected in any Pinnipeds inhabiting the northern part of the Pacific Ocean. The results of our studies allow us to state that COPs have been present in the ecosystem are the Sea of Japan for a long time and have undergone substantial transformation.  相似文献   

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Abstract Various horseradish peroxidase-conjugated lectins have been used for the ultrastructural localization of carbohydrate moieties of glycoconjugates on plasma membranes of the surface cells of Blennius sanguinolentus epidermis. Concanavalia ensiformis (Con A), Arachis hypogaea (PNA), Pisum sativum (PSA) and Ulex europaeus (UEA I) lectins bind only to the outermost plasma membranes, the glycocalyx and the intercellular spaces of the surface cells. Other lectins applied, such as Triticum vulgare (WGA), Glycine max (SBA) and Griffonia simplicifolia (GS I), presenting GlcNAc and GaINAc specificity, reacted with the plasma membranes of basolateral domains and gave an attenuated reaction with the outermost plasma membranes. The results suggest that regional differences exist in the distribution patterns of GlcNAc and GalNAc-terminating glycoconjugates. The possible implication of the polarized expression of these glycoconjugates in ion transport is discussed.  相似文献   

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Juvenile animals often suffer from high levels of predation. Development of an effective and efficient locomotor system is therefore likely to be crucial towards ensuring their survival. However, our understanding of locomotor efficiency, at least in terms of energetic cost in young animals is poor. We performed this study as Svalbard rock ptarmigan, Lagopus muta hyperborea must rapidly develop the ability to locomote prior to the onset of their first winter, during which conditions are extreme. To aid survival, adult ptarmigan deposit large winter fat stores, whilst at the same time males exhibit a reduced metabolic cost of locomotion. Sub-adult males, however, are unable to fully acquire fat stores during their first winter and the maturity of their locomotor systems is unknown. Here, we investigate the energetics and kinematics of terrestrial locomotion in sub-adult male birds using flow-through respirometry and high-speed video recordings, respectively. We demonstrate that in terms of running speed and metabolic cost, sub-adult ptarmigan develop a mature functioning locomotor system prior to the onset of winter. This research indicates that achieving a mature locomotor system allows young males to emerge from the winter with the ability to compete for territories and mates during the breeding season.  相似文献   

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This study tested the hypothesis that differences in parenting styles between two captive populations of rhesus macaques, one living in the UK (Madingley) and the other in the USA (Yerkes), are associated with differences in the degree to which social interactions with other group members pose a risk to infants. Twenty-eight mother–infant dyads, 17 living at Madingley and 11 at Yerkes, were observed for 24 h during the first 12 wks of infant life. Mother–infant dyads living at Madingley spent a higher percentage of time in contact than those living at Yerkes. The Madingley mothers also restrained and retrieved their infants more often, and rejected them less often than the Yerkes mothers. Consistent with the prediction, the protective parenting style of the Madingley mothers was associated with higher frequency of infant kidnapping and higher risk of infant harassment from other group members. Interpopulation differences in risks to infants and parenting styles are likely to be the result of differences in social density in the two environments rather than differences in the matrilineal structure of the two populations.  相似文献   

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This paper presents data on the numbers of nesting common and Kamchatka tern populations on the northeastern coast of Sakhalin Island over a more than 20-year period. Distribution maps of the main tern colonies (Chaika, Lyarvo, and Wrangel islands, and an unnamed island situated in Chaivo Bay) are given. Taking into account the current data concerning southern Sakhalin colonies, the total number of terns in Sakhalin Island is about 9000 pairs for the Kamchatka tern and up to 16000 pairs for the common tern. The main biotic and abiotic factors that determine the population dynamics and distribution of nesting terns in northern Sakhalin Island are enumerated.  相似文献   

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The chromosome set of G. melanostomus (Pallas) consists of 46 acrocentric chromosomes (2n-46). There are 30 chromosomes in the caryotype of G. batrachocephalus (Pallas): 16 metacentric and 14 acrocentric. The equal number of arms in the chromosome sets of the studied fish (FN-46) evidences for phylogenetic relationships of these species.  相似文献   

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Functional diversity indices are used to facilitate a mechanistic understanding of many theoretical and applied questions in current ecological research. The use of mean trait values in functional indices assumes that traits are robust, in that greater variability exists between than within species. While the assertion of robust traits has been explored in plants, there exists little information on the source and extent of variability in the functional traits of higher trophic level organisms. Here we investigated variability in two functionally relevant dung beetle traits, measured from individuals collected from three primary forest sites containing distinct beetle communities: body mass and back leg length. In doing so we too addressed the following questions: (i) what is the contribution of intra vs. interspecific differences in trait values; (ii) what sample size is needed to provide representative species mean trait values; and (iii) what impact does omission of intraspecific trait information have on the calculation of functional diversity (FD) indices from naturally assembled communities? At the population level, interspecific differences explained the majority of variability in measured traits (between 94% and 96%). In accordance with this, the error associated with calculating FD without inclusion of intraspecific variability was low, less than 20% in all cases. This suggests that complete sampling to capture intraspecific variance in traits is not necessary even when investigating the FD of small and/or naturally formed communities. To gain an accurate estimation of species mean trait values we encourage the measurement of 30–60 individuals and, where possible, these should be taken from specimens collected from the site of study.  相似文献   

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The annual range of body temperatures (14–35°C) of emergent mudskippers are substantially less than that of air temperatures (10–42°C) as a result of behavioural thermoregulation. In winter, low surface temperatures are avoided by remaining in burrows. Newly emerged mudskippers then bask until body temperatures rise above 14°C before they move onto the mud. In summer, body temperatures are kept lower than ambient by selecting areas where evaporative cooling is high. Body temperatures generally match those of wet mud, which can be 7°C lower than air shade temperatures. The smaller, more terrestrial, Periophthalmus koelreuteri have body temperatures which are mainly lower in summer and higher in winter than Boleophthalmus boddarti .  相似文献   

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Aphodius dung beetles produce substrate vibrations by means of an abdomino-alary stridulatory organ. Applying a method that allows the recording of Aphodius vibrations under natural conditions in a small amount of dung, the stridulatory behavior of Aphodius ater was investigated. Male A. ater are acoustically active, while females rarely stridulate. Males have a complex song, which consists of a series of different patterns that are displayed in a specific order over a considerable time when a female is encountered in the dung. Different populations show the same stridulatory patterns but individual variability is high and males display songs with differing complexity. It is hypothesized that females use the information within the song in the context of mate choice.  相似文献   

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