Über die Karpelle verschiedener Magnoliales. VIII. Überblick über alle Familien der Ordnung

Zusammenfassung Es wird eine Übersicht über die Karpellformen der Magnoliales gegeben, die auf eigenen Untersuchungen und auf kritischer Auswertung der Literaturangaben beruht. Sie ergibt, daß die Mehrzahl der Familien dieser Ordnung (nämlich 14 von insgesamt 22) peltat gebaute Karpelle besitzt, und daß darüber hinaus sich gelegentlich auch an den Karpellen der restlichen Familien Baueigentümlichkeiten (z. B. unifaziale Karpellstiele) zeigen, die in morphologischer Beziehung zur Peltation stehen. Da nun bekanntlich die Magnoliales vielfach als die ursprünglichste Ordnung der Angiospermen angesehen werden, besitzt die daraus sich ergebende Folgerung, daß nämlich die peltat-schlauchförmig gebauten Karpelle nicht nur in morphologischer, sondern auch in phylogenetischer Hinsicht die Grundform der Angiospermen-Megasporophylle darstellen, einen hohen Grad von Wahrscheinlichkeit.     

Summer feeding strategy of the little auk (Alle alle) from Bjørnøya, Barents Sea

Summer food of the little auks nesting on Bjornoya consisted of large copepods, decapod larvae and pelagic amphipods. Food items of 4–6?mm constituted the most common prey size fraction. This prey size range appears to be optimal (most profitable) with regard to the balance between mean individual mass and density of items in the surface layers of the sea. Little auks from Bjørnøya only sporadically take the abundant copepod Calanus finmarchicus (2–3.5?mm in length) but select the much less abundant and larger Calanus glacialis (3–6?mm).RID="ID=" Acknowledgements The authors would like to thank Dr. Monika Normant from the University of Gdansk for her assistance with caloric measurments, and Lech Illiszko and Adam Wajrak for their help with the fieldwork on Bj&;oslash;rn&;oslash;ya.RID="ID=" Correspondence to J. M. We&;cedil;s&;lstrok;awski     

An important late summer aggregation of fin whales Balaenoptera physalus,little auks Alle alle and Brünnich’s guillemots Uria lomvia in the eastern Greenland Sea and Fram Strait: influence of hydrographic structures

The distribution at sea of upper trophic levels—seabirds and marine mammals—is depending on their food availability: high concentrations reflect high prey abundance and thus high biological production. Polar marine ecosystems are characterized by low biodiversity and high biological patchiness. The distribution of predators, as a consequence, shows a similar patchiness. During two expeditions of icebreaking RV Polarstern in June–July 2011, biodiversity in the arctic marine zone north of 70°N was very low, with low numbers of species: 20 seabirds, eight cetaceans, five pinnipeds and polar bear. Moreover, a few species accounted for the majority in numbers: four bird species for 95 % of the total of 23,000 seabirds recorded during 700 transect counts: fulmar Fulmarus glacialis, kittiwake Rissa tridactyla, Brünnich’s guillemot Uria lomvia and little auk Alle alle. Among the marine mammals, 250 fin whales Balaenoptera physalus accounted for 80 % of the identified large cetaceans, 270 white-beaked dolphin Lagenorhynchus albirostris for 100 % of the small cetaceans and 180 harp seals Pagophilus groenlandica for 80 % of the identified pinnipeds. Their quantitative distribution was depending on water masses and oceanic fronts, large cetaceans—mainly fin whales—showing an important aggregation on the shelf slope off western Spitsbergen, as well as little auks and Brünnich’s guillemots. So that this zone, shelf slope and front of mixed Arctic/Atlantic Waters, showed unusually high seabird and cetacean concentrations. Seasonal factors possibly influencing their distribution are addressed.