216 research outputs found
First recording of the non-native species Beroe ovata Mayer 1912 in the Aegean Sea
A new alien species Beroe ovata Mayer 1912 was recorded in the Aegean Sea. It is most likely that this species spread on the currents from the Black Sea. Beroe ovata is also alien to the Black Sea, where it was introduced in ballast waters from the Atlantic coastal area of the northern America. The species is established in the Black Sea and has decreased the population of another invaderMnemiopsis leidyi, which has favoured the recovery of the Black Sea ecosystem.We compare a new 1 species with the native species fam. Beroidae from the Mediterranean and predict its role in the ecosystem of the Aegean Sea using the Black Sea experience
Annual assessment of the predation of Mnemiopsis leidyi in a new invaded environment, the Kiel Fjord (Western Baltic Sea): a matter of concern?
The sudden occurrence of the ctenophore Mnemiopsis leidyi has been reported recently from different regions of the Baltic Sea and it has been suggested that the species has invaded the whole basin. Here we provide the first set of quantitative data of seasonal diet composition and life history traits of M. leidyi and its predatory role in the pelagic ecosystem of the Western Baltic Sea. The size structure of the species appeared to be dominated by small size classes and only a few adults were as large as those reported in the native region of the species and in other invaded areas. We show that the species has a high preference for small-sized and slow swimming prey, mainly during the winter low temperature period. Barnacle nauplii appeared to be the main source of carbon for the over-wintering population of M. leidyi. A preference for copepods was only found during August when these prey contributed up to 20% of the gut composition. In summer, planula larvae of the jellyfish Aurelia aurita were the most abundant prey in the gut content (feeding rate of 621 ind. ctenophore−1day−1). We further found that at highest densities of the species, in summer, a significant predation on its larvae occurs, this being the major carbon source of adults. Overall, these results are discussed in the context of trade-offs M. leidyi faces in the new environment and adverse environmental conditions, which are likely forcing the species toward reduced sizes and also probably reducing its potential predatory impact in the Baltic Sea
First record of Mnemiopsis leidyi A. Agassiz 1865 in the Baltic Sea
The invasive ctenophore Mnemiopsis leidyi was first recorded in the Kiel Bight (western Baltic Sea) on 17 October 2006 during a regular weekly sampling program. The M. leidyi abundance gradually increased from 29.5±12.7 ind.m-3 in mid-October to 92.3±22.4 ind.m-3 in late November 2006. The occurrence of M. leidyi in the Baltic Sea is of great concern as this invader has caused negative impacts in the southern seas of Europe
Monitoring as the necessary condition of quality of training in Russian language in elementary school
В статье дается определение мониторинга, названы виды мониторинга, используемые в школе, описаны особенности мониторинга в ходе освоения русского языка. Мониторинг освоения русского языка рассматривается в качестве информационной, диагностической, прогностической системы. Отмечаются основные характеристики мониторинга: системность и систематичность. Описана совместная деятельность учителя и ученика в ходе освоения предмета, в частности русского языка. Рассмотрены основные процедуры системы мониторинга - мониторинг контрольный, промежуточный и итоговый. Названы эффективные виды мониторинга по русскому языку: диктант, изложение, сочинение, тестирование, тренинговые карточки с грамматическими заданиями.The article defines monitoring, identifies the types of monitoring used in school, describes the features of monitoring during the development of the Russian language. Monitoring the development of the Russian language is considered as an information, diagnostic, prognostic system. The main characteristics of monitoring are: systematic and systematic. The joint activity of the teacher and the student in the course of mastering the subject, in particular the Russian language, is described. The main procedures of the monitoring system are considered - control monitoring, intermediate and final monitoring. Named effective ways of monitoring the Russian language: dictation, presentation, composition, testing, training cards with grammatical tasks
Astana the capital of Kazakhstan and Astanas in Siberia as a linguistic-cultural aspect of the national Islam of Eurasia
By the time Islam penetrated into the Siberia and Kazakhstan, these territories were inhabited by various Turkic nomadic tribes whose spiritual and religious life was very varied. From the earliest age, a variety of cultural and ideological systems coexisted, including huge range of autochthonous ancient beliefs based on nature worship and ancestor worship, involving magic and the deification of the sky (Tengrism). After unification with Islam, these beliefs could later be found in the culturally-based traditional lifestyles of Siberian Tatars and Kazakhs. This is particularly true in the peripheries of the spread of Islam - in Siberia and Northern Kazakhstan, with their largely nomadic ways of life. The authors speculate on the name, astana, given to a succession of topographical objects, suggesting it represents a method for concealing the sacred in the profane. In modern socio-cultural reality, considering the mythological potential of a name involves examining fundamental characteristics of the culture such as 1. the interactive nature of culture itself, 2. its mythology, 3. its appeal to the potential of the past in search of the lost eternal values, and 4. the primacy of cultural interactions with respect to social processes. Whether the reader agrees or disagrees with this, one thing is clear: everything, even the tiniest shades of meaning that may arise in the human mind, must be considered. The vivid, powerful, multifaceted image that arises from the valuation of toponymical objects is valuable for the modern man; it rebuilds the ruined individualism and immensity of the world, thus broadening our own cultural space. The sacral complex of an astana can be understood as a kind of socio-cultural communication which provides a record of a collective tradition
Invasion Pathway of the Ctenophore Mnemiopsis leidyi in the Mediterranean Sea
Gelatinous zooplankton outbreaks have increased globally owing to a number of human-mediated factors, including food web alterations and species introductions. The invasive ctenophore Mnemiopsis leidyi entered the Black Sea in the early 1980s. The invasion was followed by the Azov, Caspian, Baltic and North Seas, and, most recently, the Mediterranean Sea. Previous studies identified two distinct invasion pathways of M. leidyi from its native range in the western Atlantic Ocean to Eurasia. However, the source of newly established populations in the Mediterranean Sea remains unclear. Here we build upon our previous study and investigate sequence variation in both mitochondrial (Cytochrome c Oxidase subunit I) and nuclear (Internal Transcribed Spacer) markers in M. leidyi, encompassing five native and 11 introduced populations, including four from the Mediterranean Sea. Extant genetic diversity in Mediterranean populations (n = 8, Na = 10) preclude the occurrence of a severe genetic bottleneck or founder effects in the initial colonizing population. Our mitochondrial and nuclear marker surveys revealed two possible pathways of introduction into Mediterranean Sea. In total, 17 haplotypes and 18 alleles were recovered from all surveyed populations. Haplotype and allelic diversity of Mediterranean populations were comparable to populations from which they were likely drawn. The distribution of genetic diversity and pattern of genetic differentiation suggest initial colonization of the Mediterranean from the Black-Azov Seas (pairwise FST = 0.001–0.028). However, some haplotypes and alleles from the Mediterranean Sea were not detected from the well-sampled Black Sea, although they were found in Gulf of Mexico populations that were also genetically similar to those in the Mediterranean Sea (pairwise FST = 0.010–0.032), raising the possibility of multiple invasion sources. Multiple introductions from a combination of Black Sea and native region sources could be facilitated by intense local and transcontinental shipping activity, respectively
Reproduction of the ctenophore, Beroe ovata, in the Caspian Sea water
The experiments with Beroe ovata showed that this ctenophore can survive and reproduce in the Caspian Sea water, though at far lower rate than in the Black Sea; larval growth in the Caspian Sea water was also slower and mortality higher. Maximum fecundity of 2210 and 240 eggs recorded in laboratories of Turkey and Iran, respectively. About 34 to 100% of eggs in the Caspian Sea water could not develop and hatch. Larvae were at different stages of development, usually with size between 1.2 to 2mm. The highest number of eggs and larvae were obtained in tanks where Beroe individuals were together with Mnemiopsis leidyi. The poor reproduction of B. ovata in the Caspian Sea water could be due to both the acclimation stress to low salinity and possible damage of individuals during the transportation
First records of Mnemiopsis leidyi (Ctenophora) from the Ligurian, Thyrrhenian and Ionian Seas (Western Mediterranean) and first record of Phyllorhiza punctata (Cnidaria) from the Western Mediterranean.
* Corresponding author Abstract The gelatinous macroplankters Mnemiopsis leidyi and Phyllorhiza punctata are recorded for the first time from the Italian coasts of the Western Mediterranean. In the framework of the CIESM Jellywatch campaign in the summer of 2009, M. leidyi was recorded from the Ligurian, Tyrrhenian, and Ionian Seas, including swarming episodes that, together with those reported from Spain in the same period, suggest a great success of the species in the Western Mediterranean. A single specimen of P. punctata has been recorded from Sardinia. These species do not sting or harm humans and no impact on tourism is expected, but they might harm fisheries by predating on fish eggs and larvae and their prey, zooplankton. The large distribution area of M. leidyi suggests that the species invaded the Western Mediterranean during the summer of 2009, but its establishment is still uncertain, since the populations might not withstand winter conditions. The isolated record of P. punctata just indicates that it can reach this part of the Mediterranean
First report on Beroe ovata in an unusual mixture of ctenophores in the Great Belt (Denmark)
Non-native species spread in a complex network: the interaction of global transport and local population dynamics determines invasion success
The number of released individuals, which is a component of propagule pressure, is considered to be a major driver for the establishment success of non-native species. However, propagule pressure is often assumed to result from single or few release events, which does not necessarily apply to the frequent releases of invertebrates or other taxa through global transport. For instance, the high intensity of global shipping may result in frequent releases of large numbers of individuals, and the complexity of shipping dynamics impedes predictions of invasion dynamics. Here, we present a mathematical model for the spread of planktonic organisms by global shipping, using the history of movements by 33 566 ships among 1477 ports to simulate population dynamics for the comb jelly Mnemiopsis leidyi as a case study. The degree of propagule pressure at one site resulted from the coincident arrival of individuals from other sites with native or non-native populations. Key to sequential spread in European waters was a readily available source of propagules and a suitable recipient environment. These propagules were derived from previously introduced ‘bridgehead’ populations supplemented with those from native sources. Invasion success is therefore determined by the complex interaction of global shipping and local population dynamics. The general findings probably hold true for the spread of species in other complex systems, such as insects or plant seeds exchanged via commercial trade or transport
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