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581.
Linas BALIAUSKAS Albina AMSHOKOVA Laima BALIAUSKIEN Ana Maria BENEDEK Jan CICHOCKI Alexander CSANDY Philippe Gil DE MENDONA Victoria NISTREANU 《Integrative zoology》2020,15(1):55-68
Patterns of body size variation along geographical gradients have long been searched for and generalized into eco‐geographical rules. However, no rodent species has yet been analyzed in relation to the 3 dimensions of latitude, longitude and altitude. We analyzed geographical clines and dimorphism of body and skull size in the herb field mouse (Apodemus uralensis) across the species range, based on field data and on data from the literature. Sexual dimorphism in adult A. uralensis was not expressed at a large scale, while local patterns were inconsistent. Age‐dependent size changes were most expressed in adult individuals: most characters of adults exceeded in size those of subadults, while subadult–juvenile size differences were only significant in body weight and length, zygomatic skull width, length of cranial diastema and breadth of braincase. Despite central morphological niches along the clines being separated, A. uralensis populations showed a high degree of size overlap in morphological space. We found the species to be characterized by high size variability, with the largest individuals inhabiting the eastern and southern edges of the distribution range. Tail, hind foot and ear lengths were largest in the southern part of the range, in agreement with Allen's rule. The main measurements that we analyzed, namely body mass, zygomatic skull width and condylobasal skull length, show the presence of 3 clines in the size of adult A. uralensis: (i) a decreasing south–north cline, opposing Bergmann's rule; (ii) an increasing west–east cline, in accordance with Murphy's rule; and (iii) an increasing altitudinal cline. 相似文献
582.
Antonio C. GALLO Cinthia A. BRASILEIRO Fbio Cury DE BARROS Jos Eduardo DE CARVALHO 《Integrative zoology》2020,15(1):40-54
It is well known that environmental temperature influences several biological functions of ectotherms, notably in amphibians. The high permeability of anuran skin, associated with the effect of elevated environmental temperature, potentiates the dehydration process and this combination may restrict locomotor performance. Thoropa taophora is an endemic species from the Atlantic Rainforest whose tadpoles are semiterrestrial and predominantly diurnal, and are found in rocky seashores where they are exposed to sea spray and high temperatures. In this study we investigated how temperature and salinity conditions affect the locomotor performance in Thoropa taophora tadpoles. We also assessed how different osmotic concentrations affect the activity of the metabolic pathways that support muscle function. We measured the sprint speed of tadpoles of various sizes at different temperatures and salinities in the field. We also measured the activity of the enzymes pyruvate kinase (PK), lactate dehydrogenase (LDH) and citrate synthase (CS) in different temperatures and osmotic concentrations, and calculated the thermal sensitivity and the activity constants for each osmolality. Our results showed that, in general, sprint speed decreased with increasing temperature and salinity. However, whereas the effect of increased salinity was similar in smaller and larger tadpoles, increased temperature had a higher negative impact on sprint speed of larger tadpoles, thus indicating low thermal sensitivity of small tadpoles. PK and LDH thermal sensitivities and LDH constant of activity decreased as the osmolality increased. In conclusion, the locomotor capacity of tadpoles was decreased by temperature and salinity, which may be related to a decrease in anaerobic metabolism both in terms of sensitivity and total energy turnover through enzymatic activity. We discuss the ecological consequences, including the potential impacts on predator escape behavior promoted by changes in metabolism and locomotor performance in an early stage of development of this species. 相似文献
583.
Xin ZHANG Yanyu WANG Lena SCHULTE-UEBBING Wim DE VRIES Tan ZOU Eric A. DAVIDSON 《农业科学与工程前沿(英文版)》2022,9(3):356
584.
为研究氮素添加对植物多样性与土壤养分含量的影响,本研究以青海省称多县高寒草甸为对象,在添加不同水平氮素(N0(0 gN·m-2)、N1(15 gN·m-2)、N2(30 gN·m-2)、N3(45 gN·m-2)、N4(60 gN·m-2))后测定植物表型性状(盖度、高度及生物量)和土壤养分(全氮、硝态氮、铵态氮、有机碳、全磷)含量等相关指标。结果表明:当添加量为60 gN·m-2时,植物群落多样性指数显著下降(P<0.05);随着氮素添加水平升高,土壤养分含量变化不同。其中氮素添加下植物群落多样性与土壤因子间存在相关性。土壤有机碳和铵态氮含量是影响植物多样性最大的土壤因子。综上所述,短期氮素添加通过影响高寒草甸土壤碳、氮、磷含量及其计量比,进而影响植物群落多样性。 相似文献
585.
Diego Leandro REIS DA SILVA FERNANDES Matheus FILGUEIRA BEZERRA Marise SOBREIRA BEZERRA DA SILVA Nilma Cintra LEAL Christian Robson DE SOUZA REIS Alzira Maria Paiva DE ALMEIDA 《Integrative zoology》2021,16(6):810-819
Plague, caused by the Yersinia pestis bacterium, has several foci scattered throughout a large area from the Brazilian territory that ranges from the Northeastern State of Ceará to the Southeastern State of Minas Gerais and another separated area at the State of Rio de Janeiro. This review gathers data from plague control and surveillance programs on the occurrence and geographic distribution of rodent hosts and flea vectors in the Brazilian plague areas during the period of from 1952 to 2019. Furthermore, we discuss how the interaction between Y. pestis and some rodent host species may play a role in the disease dynamics. The absence of human cases nowadays in Brazil does not mean that it was eradicated. The dynamics of plague in Brazil and in other countries where it was introduced during the 3rd pandemic are quite alike, alternating epidemics with decades of quiescence. Hence, it remains an important epidemic disease of global concern. The existence of a large animal reservoir and competent vectors demonstrate a need for continuous surveillance to prevent new outbreaks of this disease in humans. 相似文献
586.
Ahmad MAHMOUDI Boris KRYŠTUFEK Alexander SLUDSKY Boris V. SCHMID Alzira M. P. DE ALMEIDA Xu LEI Beza RAMASINDRAZANA Eric BERTHERAT Aidyn YESZHANOV Nils Chr. STENSETH Ehsan MOSTAFAVI 《Integrative zoology》2021,16(6):820-833
Plague has been known since ancient times as a re-emerging infectious disease, causing considerable socioeconomic burden in regional hotspots. To better understand the epidemiological cycle of the causative agent of the plague, its potential occurrence, and possible future dispersion, one must carefully consider the taxonomy, distribution, and ecological requirements of reservoir-species in relation either to natural or human-driven changes (e.g. climate change or urbanization). In recent years, the depth of knowledge on species taxonomy and species composition in different landscapes has undergone a dramatic expansion, driven by modern taxonomic methods such as synthetic surveys that take into consideration morphology, genetics, and the ecological setting of captured animals to establish their species identities. Here, we consider the recent taxonomic changes of the rodent species in known plague reservoirs and detail their distribution across the world, with a particular focus on those rodents considered to be keystone host species. A complete checklist of all known plague-infectable vertebrates living in plague foci is provided as a Supporting Information table. 相似文献
587.
R. L. Plaisted DE. Halseth B. B. Brodie H. D Thurston S. A. Slack R. Loria E. D Jones J. B. Sieczka 《American Journal of Potato Research》1990,67(4):239-243
Steuben is a golden nematode resistant variety with wide adaptation and high yield potential. It has a mid to late season vine maturity but starts to size its crop of tubers as early as Superior. It has potential for tablestock as well as for chipping from the field and from 10°C storage. It is resistant to pitted scab but susceptible to superficial scab which can be severe enough to reduce its value for tablestock under some conditions. The maturity of the crop entering storage appears to be an important determinant for chip color out of storage. 相似文献
588.
Abstract Exotic cichlids, introduced to Asia during the second half of the twentieth century, contribute significantly to the reservoir fisheries in the region. The two major cichlid species, Oreochromis mossambicus (Peters) and O. niloticus (L.), tend to interbreed easily. In Sri Lankan reservoirs, introgressive hybridization of these two cichlids takes place. The reproductive biology of O. mossambicus, O. niloticus and their hybrids in three reservoirs in Sri Lanka was evaluated. An imbalance in sex ratio with male dominance was evident. The estimated fecundity for 20-cm fish, using fecundity-total length relationships for various populations, indicated that there was a decline in fecundity in hybrid forms. It is hypothesized that the long-term effect of crosshybridization between the two cichlids might lead to a decline in fish yields in perennial reservoirs of Sri Lanka. The importance of the findings of the present study for the management of the reservoir fisheries in Asia is highlighted. 相似文献
589.
Abstract. Oreochromis niloticus (L.) young of two size groups, 170-213 mg (±7) and 1-017-1-072 g (±0-04), were reared under seven different dietary schedules for 70 days. The two control diets had 18% and 30% protein content; the other five schedules were randomly determined, where the feeding of the low-protein diet alternated with the high-protein diet, for differing periods. On the basis of the observed rate of growth, food conversion ratio, protein efficiency ratio and percentage protein retained in both size groups of young O. nitoticus, those reared on a dietary schedule of 2A/3B performed best followed by those reared on schedule 1A/3B; where the numerical value refers to the number of days a particular diet was offered continuously. The feed cost-saving factor, by adopting alternate feeding schedules as compared to presenting a high-protein diet continuously, is shown to be significant. 相似文献
590.
Abstract. Two species of tilapia, Oreochromis mossambicus (Peters) and O. niloticus (L.), from five reservoirs in southern Sri Lanka as well as fish from a fish hatchery and laboratory stock were studied by starch gel electrophoresis at 18 enzyme loci, to determine the degree of mixing of the two species. Two reservoirs showed little or no mixing between O. mossambicus and O. niloticus , while two other reservoirs as well as the hatchery stock showed a high degree of mixing of the two species. The laboratory stock of O. niloticus also showed introgression of O. mossambicus alleles. The similarities of the local stocks to the original African as well as other Asian stocks is discussed. 相似文献