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Number of results: 7
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Abstract

Deep−sea benthic Ostracoda (Crustacea) in Icelandic waters are poorly known. Here we report deep−sea ostracode assemblages from the multiple core (MUC) and the epibenthic sledge (EBS) samples collected from Icelandic waters by the first cruise of the IceAGE (Icelandic Marine Animals: Genetics and Ecology) project. Samples from shelf − −edge and lower−bathyal working areas are examined. The results show (1) distinct MUC and EBS faunas due to the large difference in mesh size of MUC and EBS; and (2) distinct shelf−edge and lower−bathyal ostracode faunas. Such remarkable faunal turnover from shelf to bathyal depths is similar to the faunal turnovers reported from depth transects in the adjacent regions of the western North Atlantic Ocean, the Greenland Sea, and the North Sea, but, at the same time, there are certain differences in the faunal composition between the Icelandic waters and these adjacent regions. In addition, we illustrate many Icelandic deep−sea ostracode species with high−resolution scanning electron microscopy and composite all−in−focus stereomicroscopic images for the first time. These results provide important basic information on deep−sea ostracode research and biogeography of this important region connecting North Atlantic proper and Nordic Seas.
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Authors and Affiliations

Moriaki Yasuhara
Maria Grimm
Simone N. Brandão
Anna Jöst
Hisayo Okahashi
Hokuto Iwatani
Alexandra Ostmann
Pedro Martínez Arbizu
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Abstract

Collections of munnopsid isopods of the BIOICE (Benthic Invertebrates of Icelandic Waters; 1991–2004) and the IceAGE1 (Icelandic Marine Animals: Genetics and Ecology; since 2011) expeditions included ten species of the genus Eurycope G.O. Sars, 1864, thereof are two species new to science. Thus, the descriptions of the two new species are presented herein. Eurycope elianae sp. n. is distinguished from the other species of the genus mainly by two long, slightly robust, simple setae on the tip of the rostrum in combination with the size and shape of the rostrum itself. E elianae sp. n. shares the presence of two long, slightly robust, simple seta on the tip of the rostrum with E. tumidicarpus . The shape of the rostrum itself is more similar to E. inermis and species of the E. complanata complex. E. aculeata sp. n. is characterized by possessing dorsomedial acute projections on pereonites 5–7, which is unusual for the genus. E. aculeata sp. n. is most similar to E. cornuta . Both new species are, so far, known only from localities south of the Greenland−Scotland Ridge.
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Authors and Affiliations

Sarah Schnurr
Marina V. Malyutina
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Abstract

In Tanaidacea morphological identification of male individuals to the species level is complicated by two factors: the presence of multiple male stages/instars confuse the assessment of sexual stage while strong sexual dimorphism within several families obscures the morphological affinities of undescribed males to described females. Males of Paratanaoidea are often morphologically quite different from females and have not been discovered for most genera so far, which has led to the assumption that some tanaidaceans might have parthenogenetic reproduction or simply have undeveloped secondary sex traits. As a part of the IceAGE project (Icelandic marine Animals: Genetics and Ecology), with the support of molecular methods, the first evidence for the existence of highly dimorphic (swimming) males in four families of the superfamily Paratanaoidea (Agathotanaidae, Cryptocopidae, Akanthophoreidae, and Typhlotanaidae) is presented. This study suggests that these males might be the next instars after juvenile or preparatory males, which are morphologically similar to females. It has been assumed that “juvenile” males with a restricted ability for swimming ( e.g. , undeveloped pleopods) have matured testes, are capable of reproduction, and mate with females nearby, while swimming males can mate with distant females. Our explanation of the dimorphism in Tanaidomorpha lies in the fact that males of some species ( e.g. , Nototanais ) retain the same lifestyle or niche as the females, so secondary traits improve their ability to guard females and successfully mate. Males of other species that have moved into a regime (niche) different than that of the female have acquired complex morphological changes ( e.g. , Typhlotanais ).
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Authors and Affiliations

Magdalena Błażewicz-Paszkowycz
Robert M. Jennings
Karen Jeskulke
Saskia Brix
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Abstract

Sediment samples and hydrographic conditions were studied at 28 stations around Iceland. At these sites, Conductivity−Temperature−Depth (CTD) casts were conducted to collect hydrographic data and multicorer casts were conducted to collect data on sediment characteristics including grain size distribution, carbon and nitrogen concentration, and chloroplastic pigment concentration. A total of 14 environmental predictors were used to model sediment characteristics around Iceland on regional scale. Two approaches were used: Multivariate Adaptation Regression Splines (MARS) and randomForest regression models. RandomForest outperformed MARS in predicting grain size distribution. MARS models had a greater tendency to over− and underpredict sediment values in areas outside the environmental envelope defined by the training dataset. We provide first GIS layers on sediment characteristics around Iceland, that can be used as predictors in future models. Although models performed well, more samples, especially from the shelf areas, will be needed to improve the models in future.
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Authors and Affiliations

Alexandra Ostmann
Sarah Schnurr
Pedro Martínez Arbizu
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Abstract

Twelve glaciers, representing various types, were investigated between 2000 and 2005, in a region adjacent to the northern reaches of Billefjorden, central Spitsbergen ( Svalbard ). On the basis of measurements taken using reference points, DGPS and GPS systems, analyses of aerial photographs and satellite images, geomorphological indicators and archival data their rates of deglaciation following the “Little Ice Age” (LIA) maximum were calculated variously on centennial, decadal and annual time scales. As most Svalbard glaciers have debris-covered snouts, a clean ice margin was measured in the absence of debris-free ice front. The retreat rates for both types of ice fronts were very similar. All studied glaciers have been retreating since the termination of the Little Ice Age at the end of 19th century. The fastest retreat rate was observed in the case of the Nordenskiöldbreen tidewater glacier (mean average linear retreat rate 35 m a-1). For land-terminating glaciers the rates were in range of 5 to 15 m a-1. Presumably owing to climate warming, most of the glacier retreat rates have increased several fold in recent decades. The secondary factors influencing the retreat rates have been identified as: water depth at the grounding line in the case of tidewater glaciers, surging history, altitude, shape and aspect of glacier margin, and bedrock relief. The retreat rates are similar to glaciers from other parts of Spitsbergen . Analyses of available data on glacier retreat rates in Svalbard have allowed us to distinguish four major types: very dynamic, surging tidewater glaciers with post-LIA retreat rates of between 100 and 220 m a-1, other tidewater glaciers receding of a rate of 15 to 70 m a-1, land terminating valley polythermal glaciers with an average retreat of 10 to 20 m a-1 and small, usually cold, glaciers with the retreat rates below 10 m a-1.

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Authors and Affiliations

Grzegorz Rachlewicz
Witold Szczuciński
Marek Ewertowski
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Abstract

Among the several crises that occurred in the 16th century, the famine crisis and high prices in the years 1569–1574 had exceptional significance, as its intensity, scope and duration far out-weighed other economic collapses of the century. Despite this, the course of events and the consequences have been of virtually no interest to historians over the years, which begs the question: why? As it seems, the events connected with the crises in question were overshadowed in Western historiography by other numerous and significant political events at the time, such as the Battle of Lepanto (1571) and the Night of St. Bartholomew in France (1572). In the Polish-‑Lithuanian state, in contrast, between 1569 and 1574, the famine and high prices coincided with a crisis of royal power and the state. This, indeed, drew the attention of historians, but only to political issues, among them the Polish‑Lithuanian union of 1569, the succession to the throne after the heirless Sigismund Augustus died, the first free election, religious disputes, the flight of King Henryk Walezy (Henry III), and the neighbouring wars, rather than to the social problems connected with the mass death of the poorest in the state, and the resulting economic problems. Therefore, in this article, the author synthesises the course of the famine crisis of 1569–1574 in the Polish‑Lithuanian state and hypothesises that the events and implications of this crisis largely preserved the mentality of the nobility in the following centuries and their dominance in the economic and political life of the Commonwealth. This crisis also influenced a choice of different path for development of the Commonwealth compared to other European countries. To clarify, the author does not claim to have exhausted the subject, and the article is intended to spur a discussion and further detailed research.
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Authors and Affiliations

Jacek Wijaczka
1
ORCID: ORCID

  1. Wydział Nauk Historycznych UMK w Toruniu

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