Eisfische – die etwas anderen Fische. Wirbeltiere ohne Blut?

Ice fish – the special fishes Ice fish lacks the oxygen‐binding haemoglobin. They do not transport oxygen in their blood by binding oxygen chemically but transport oxygen in physical solution. Their oxygen carrying capacity is less than 10% of ‘normal’ fish. They developed a number of adaptations in the evolution in order to survive successfully such as a much bigger heart, a larger blood volume and blood vessels exhibiting diameters substantially larger than in other fish. These adaptation partly compensate for the disadvantages arising out f the fact that oxygen is not bound chemically and thus be able to transport much less oxygen per unit of time than ‘normal’ fish. This article describes how ice fish have managed to compete with red‐blooded Antarctic fish and live in large numbers in the Southern Ocean.     

Der Kaiserpinguin – ein Vogel der Superlative

Emperor Pinguin – a bird of superlative The antarctic ecosystem is home of 200 million seabirds. 26 million of them belong to the penguins and only 600.000 are Emperor Penguins. They breed along the remote coasts of Antarctica. Their first colony was discovered in 1902. In the course of the 1950ies more colonies were detected and today with the help of satellite technique we know more than 54 in total. The breeding cycle starts during winter, when a 1.000 kilometer sea ice belt surrounds the continent. Emperor Penguins use Polynjas during this time to get access to the food sources in the sea. During incubation and breeding they are very hard to study due to stormy weather and temperatures of sometimes below minus 30° Celsius. From October onwards the first big icebreakers are capable to reach some of these places and biologists can start to study breeding success by counting chicks and adults. The few best monitored colonies are in the reach of Antarctic winter stations. Remote sensing of faeces stain on the ice give an introspection of the spacing of colonies all over the coasts. Counts in the colonies give figures of population sizes in relation to faeces covered areas. So we got a rough idea about the number of individuals. Satellite imaging over the last 40 years has provided data on the sea and glacier ice loss: Most loss is to be found in western Antarctica, but also in eastern Antarctica we can find more and more melting due to raising temperatures.     

中国驼鹿种群数量及分布现状的研究

1985一1987年间,作者在中国东北大、小兴安岭林区,根据三阶抽样的原理,选择1 6块样地,设置并调查202条样带,长2476．6km,遇见309条驼鹿足迹链。由此,明确了驼鹿在中国的分布区域并确定总栖息面积为1 9万多km² ．平均分布密度为0.0519头／km²,种群数量为9955士397头(a=0．2 ）,其种群下降率年平均逃6.3 %,且呈继续下降趋势, 亟待保护。     

Patterns of hunting mortality in Norwegian moose (Alces alces) populations

We used a simple life table approach to examine the age-specific patterns of harvest mortality in eight Norwegian moose populations during the last 15 years and tried to determine if the observed patterns were caused by hunter selectivity. The general opinion among local managers is that hunters prefer to shoot female moose not in company with calves to keep a high number of reproductive females in the population (and because of the emotional stress involved in leaving the calf/calves without a mother), and relatively large males because of the higher return with respect to meat and trophy. In support of the former view, we found the harvest mortality of adult females to be higher among pre-prime (1–3 years old) than prime-aged age classes (4–7 years old). This is probably because prime-aged females are more fecund and, therefore, more likely to be in company with one or two calves during the hunting season. As the season progressed, however, the selection pressure on barren females decreased, probably due to more productive females becoming ‘legal’ prey as their calf/calves were harvested. In males, we did not find any evidence of strong age-specific hunter selectivity, despite strong age-dependent variation in body mass and antler size. We suggest that this was due to the current strongly female-biased sex ratio in most Norwegian moose populations, which leaves the hunters with few opportunities to be selective within a relatively short and intensive hunting season. The management implications of these findings and to what extent the results are likely to affect the future evolution of life histories in Norwegian moose populations are discussed.Electronic Supplementary Material Supplementary material is available for this article at and accessible for authorised users.     

Associational resistance mediates interacting effects of herbivores and competitors on fireweed performance

Neighboring plants may have dual roles in relation to focal plants, being both competitors, and mediators of associational resistance (AR), or associational susceptibility (AS) to herbivores. Even though these two roles are played out simultaneously in nature, they have traditionally been studied separately. We conducted a two-by-two factorial experiment by manipulating the occurrence of neighbors (meadowsweet, Filipendula ulmaria) and shared mammal herbivores (moose, Alces alces) to investigate how the two simultaneously affect the performance of focal fireweed (Chamerion angustifolium) plants.We found that interactions between mammal herbivory and neighbors had significant effects on fireweed performance. These effects were explained by two counteracting mechanisms. First, when mammal herbivores were present, fireweed experienced AR such that plants growing outside of meadowsweet patches had an almost tripled risk of being browsed compared to plants growing among meadowsweet, resulting in reduced fireweed reproduction and growth. Second, when mammals were excluded, the association with meadowsweet had a direct negative effect on fireweed growth rates – mainly due to competition for light. Additionally, for the first time, we show that association with neighbors affected mammal-induced branching in fireweed.This study demonstrates that AR mediated by mammal herbivores can flip plant–plant interactions from competitive (−) to facilitative (+), and affect plant architecture. As AR and competition are probably simultaneously co-occurring forces, interactions between the two are likely common and thus of fundamental importance for populations and communities.     

A triassic “Problematic microfossil” revealed:<Emphasis Type="Italic">Probolocuspis espahkensis</Emphasis> Brönnimann,Zaninetti, Moshtaghian and Huber 1974 is attributed to the dasycladacean algae

Summary The “problematic microfossil”Probolocuspis espahkensis, described as, “incertae sedis” by Br?nnimann, Zaninetti, Moshtaghian and Huber (1974) from the Carnian Espahk Formation near the small village of Espahk (Tabas area, NE Iran) represents a dasycladacean alga attributed preliminary to the Family Acetabulariaceae, Tribe Clypeineae. The holotype ofProbolocuspis espahkensis, designated by Br?nnimann et al. (1974), is only a part of the alga. Contribution to the Triassic Paleontology of Iran No. 8; for No. 7: see Senowbari-Daryan, B. (2002); Jb. Geol. Bundesanst., 143/I, Wien     

The influence of salinity on ionic concentrations and osmolarity of blood serum in lake sturgeon, Acipenser fulvescens

This study examined the extent to which lake sturgeon, Acipenser fulvescens, regulated serum ion concentrations and osmolarity in relation to ambient salinity. Twenty juvenile lake sturgeon, brood stock from the Moose River in the Hudson Bay drainage basin, were gradually transferred from freshwater to more saline waters at a rate of 2 day^-1. Blood was sampled from fish at 0, 10, 15 and 25 following 48 h acclimation periods. Concentrations of Na⁺, K⁺, Cl^-, Ca²⁺ and osmolarity were measured. Experimentation was terminated at 25 due to poor fish health resulting in two mortalities. Within freshwater, lake sturgeon blood serum displays similar osmotic and ionic composition to other North American species of sturgeon. Juvenile lake sturgeon do not appear capable of homeostasis above 15 nor are they tolerant to environments exceeding 25. Some evidence of greater tolerance to elevated salinities with increased size was noted. The ecological potential for resource exploitation in regions of elevated salinities is discussed.     

Factors influencing choice of balsam fir twigs from thinned and unthinned stands by moose

Summary Moose were observed to browse preferentially on balsam fir (Abies balsamea) trees in stands where the stem density had been mechanically reduced to about 2000 stems/ha from over 30,000 stems/ha. Twigs from trees in thinned and unthinned stands were analyzed to test the hypotheses that moose were choosing thinned stands to maximize intake of a nutrient, or avoiding plant secondary compounds deliterious to digestion. Analyses included: twig length, weight, diameter, acid detergent fiber, neutral detergent fiber, dry matter digestibility, macroelements, crude fat (resins), crude protein, ash, and volatile secondary metabolites. Significantly higher concentrations of crude protein, P, Ca, Na, and crude fats occurred in trees from thinned compared to unthinned stands. Twigs from thinned stands were more digestible, longer, heavier, and had a greater diameter than those from unthinned stands. Several secondary metabolites were found in highest concentration in thinned stands. We suggest that moose chose thinned stands over unthinned stands for feeding because of high protein levels and large twigs. Trees in unthinned stands had protein levels below reported maintenance levels required by moose. Secondary metabolite concentrations were opposite to the direction predicted and the data do not support plant defence hypotheses for the chemicals analyzed.     

The role of moose <Emphasis Type="Italic">Alces alces</Emphasis> L. in boreal forest – the effect on ground beetles (Coleoptera,Carabidae) abundance and diversity

The indirect effect of moose Alces alces browsing on ground beetle's abundance and diversity was investigated by pitfall trapping in a mixed coniferous forest in Vestfold County (59°19′ N, 9°50′ E, Norway), during the summer of 2002. Three areas with different browsing pressures, ranging from non- to medium- and heavily browsed were chosen and dry weight of bilberry Vaccinium myrtillus and humidity at ground level were measured in the three locations. As predicted, the gradient analyses showed that browsing by moose influenced the composition of carabid fauna, and that browsing intensity and humidity covaried with the most important gradient in carabid species composition found across the three locations. Species that live in light stands with rather dry soil, were more often captured in the browsed areas, whereas shade tolerant and hygrophilous species were more abundant in the non-browsed area. The carabid abundance increased significantly with increasing browsing pressure. According to our predictions, the diversity at trap level (α-diversity) was higher in the highly browsed area. Conversely, species turnover (β-diversity) decreased with browsing intensity. On the other hand, the rarefaction analysis showed that the regional species richness (γ-diversity) was considerably higher in the medium browsed area than in the heavily browsed one, which is consistent with the intermediate disturbance hypothesis. This study indicates that moose, by reducing the bilberry that constitutes the field layer in summer, affect carabid species composition and might be capable to reshape the whole ecosystem in our study area by a cascade effect.     

Kontaktwinkeluntersuchungen zur beurteilung der benetzung von blattoberflächen durch wässrige lösungen nichtionogener tenside

Die abgestufte Wirkung einer ethoxylierten Tensidreihe auf den Kontaktwinkel wurde am Beispiel der Genapol X‐Typen untersucht. Optimale Erniedrigungen der Kontaktwinkel wurden für X‐080 bzw. X‐060 erhalten, wobei der Unterschied zu den Typen mit geringerer EO‐Kettenlänge unbeträchtlich ist bzw. innerhalb des Meßfehlers liegt. Die .unterschiedliche Kontaktwinkelemiedrigung bei verschiedenen Species ist erklärbar, wenn der spezielle Einfluß morphologischer Aspekte charakterisiert werden kann. Durch Untersuchung der Benetzungskinetik und der Konzentrationsabhängigkeit des Tensides lassen sich zusätzliche detailierte Informationen über den Benetzungsprozeß erhalten.