Weitere biologische Literatur (eingeschränkter Zugriff)
Das Geruchsorgan von Pipa americana
Introduction to a review of the genus Corvus / Colonel R. Meinertzhagen
Triassic and Lower Jurassic radiolarian biostratigraphy in the siliceous claystone and bedded chert units of the southeastern Mino Terrane, Central Japan
- The siliceous claystone and chert lithologic units of the Triassic-Jurassic chert-clastic sequence are well exposed in the Inuyama, Mt. Kinkazan and Hisuikyo areas of the southeastern Mino Terrane. Twenty-one continuous sections from those areas were investigated in order to establish comprehensive radiolarian biozones and clarify the successive lithologic changes through the Triassic and lowest Jurassic. Twenty new radiolarian zones are established; the lowest two are assemblage zones and the others are defined by the first or last occurrence of index taxa. The definitions are as follows in chronological order: TR 0, Follicucullus Assemblage Zone (early Spathian or older); TR 1, Parentactinia nakatsugawaensis Assemblage Zone (late Spathian); TR 2A, Eptingium nakasekoi Lowest-occurrence Zone (early Anisian); TR 2B, Triassocampe coronata group Lowest-occurrence Zone (early Anisian); TR 2C, Triassocampe deweveri Lowest-occurrence Zone (late Anisian); TR 3A, Spine A2 (possiblly derived from Oertlispongus inaequispinosus) Lowest occurrence Zone (late Anisian) ; TR 3B, Yeharaia elegans group Lowest-occurrence Zone (early Ladinian); TR 4A, Muelleritortis cochleata Lowest-occurrence Zone (late Ladinian); TR 4B, Spongoserrula dehli Lowest-occurrence Zone (late Ladinian to early Carnian); TR 5A, Capnuchosphaera Lowest-occurrence Zone (early Carnian); TR 5B, Poulpus carcharus sp. nov. Lowest-occurrence Zone (early to late Carnian); TR 6A, Capnodoce- Trialatus Concurrentrange Zone (late Carnian to early Norian), TR 6B, Trialatus robustus-Lysemelas olbia gen. et sp. nov. Partial-range Zone (early Norian); TR 7, Lysemelas olbia gen. et sp. nov. Lowest-occurrence Zone (early to late Norian); TR 8A: Praemesosaturnalis multidentatus group Lowest-occurrence Zone (late Norian); TR 8B: Praemesosaturnalis pseudokahleri sp. nov. Lowest-occurrence Zone (late Norian) ; TR 8C: Skirt F (possiblly derived from Haeckelicyrtium takemurai) Lowest-occurrence Zone (late Norian to early Rhaetian); TR 8D: Haeckelicyrtium breviora sp. nov. Taxon-range Zone (early to late Rhaetian) ; JR OA: Haeckelicyrtium breviora sp. nov.-Bipedis horiae sp. nov. Partial-range Zone (Hettangian); and JR OB: Bipedis horiae sp. nov. Lowest-occurrence Zone (Hettangian/Sinemurian) . These zones are correlated to previousy established radiolarian assemblages and zones in Japan and other regions. Age assignment of the zones is also discussed on the basis of the correlation and other available chronological data. The original stratigraphic succession of the Triassic in the studied area, which ranges in age from Early Triassic to Early Jurassic, is more than 100 m in thickness and can be reconstructed in detail. The succession is subdivided into seven units based on lithologic features. Each unit was probably accumulated under a particular sedimentary condition, thus successive changes of paleoceanographic environments during Triassic time can be traced continuously. Nine new genera including Ayrtonius, Blonzella, Braginella, Bulbocampe, Enoplocampe, Lysenzelas, Parvibrachiale, Spongoxystris and Veles, and 47 new species are described herein. A comprehensive list of identified taxa is presented. Key words: biostratigraphy, Central Japan, Mino Terrane, Radiolaria, Triassic.
Einige Beobachtungen über die Strömungen an der Westküste des Schwarzen Meeres
- Im Jahre 1932 wurden 4 Beobachtungen über Strömungen im Schwarzen Meere (Meerbusen Mamaia) mit folgendem Ergebnis angestellt: 1. Zwischen 24. Juni und 2. Juli wurde eine S.N.-Strömung beobachtet, deren Wasser am 26. Juni in den Meerbusen Mamaia eindrang und da ein plötzliches Temperatursinken um 8,40 C hervorrief. Die Fischbevölkerung änderte sich ebenso rasch, da mit dem kalten Wasser grosse Exemplare von Mugil cephalus, Temnedon saltator und Trachurus trachurus an der Stelle der sonst täglich an der Küste angetroffenen Fische traten. 2. Zwischen 5. und 12. Juli wurde eine Verminderung der Dichte von 1,010 auf 1,005 binnen 24 Stunden bei fast gleichbleibender Wassertemperatur festgestellt. Parallel mit der Verminderung des Salzgehaltes wurden im Meere grosse Mengen Süsswasserfische, besonders Karpfen, die aus der Donaugegend stammten, gefischt; andererseits warfen die Wellen Zweige und Wurzeln von Weidebäumen an die Küste. Diese Erscheinungen sprechen für das Vorhandensein einer N.S.-Strömung, die in dieser Zeit in den Mamaiaer Meerbusen einströmte. 3. In der Zeitspanne 22. August - 18. September wurde die N.S.-Strömung wieder beobachtet, da sie eine abermalige Verminderung des Salzgehaltes im Meerbusen herbeiführte. Am 23. August wurde die Hauptströmung zirka 10 km. vor Constantza, in der Gegend der 20-25 m. Tiefenlinie gefunden (bei 27° C war die Dichte 1,005). Durch langanhaltende und wiederholte N.O.- und O.-Winde wurde das warme Wasser der N.S.-Strömung in den Meerbusen Mamaia getrieben, sodass dort am 11. September das Dichteminimum von 1,0039 bei 22,5° C erreicht wurde. 4· Schliesslich wurde zwischen 31. Oktober und 7. November ein Eindringen von kaltem Wasser in denselben Meerbusen beobachtet, das ein plötzliches Temperatursinken von 16° C auf 6,50 C bei fast gleichbleibenden Dichtewerten zur Folge hatte. Dieses kalte Wasser gehörte der S.N.-Strömung an, denn wir stellten in dieser Zeit fest, dass die Stellnetze 100-.300 m. weit nordwärts von ihrem Platze getrieben wurden . Der Fischfang zeigte sich ergiebig zwischen 15,5° C und 8° C., während bel 6,5° C die Makrelen, die vorher in grossen Mengen gefangen wurden, ausblieben.
Repetitive shallow dives pose decompression risk in deep-diving beaked whales
Walter M. X. Zimmer
Peter L. Tyack
- The impact of naval sonar on beaked whales is of increasing concern. In recent years the presence of gas and fat embolism consistent with decompression sickness (DCS) has been reported through postmortem analyses on beaked whales that stranded in connection with naval sonar exercises. In the present study, we use basic principles of diving physiology to model nitrogen tension and bubble growth in several tissue compartments during normal div ng behavior and for several hypothetical dive profiles to assess the risk of DCS. Assuming that normal diving does not cause nitrogen tensions in excess of those shown to be safe for odontocetes, the modeling indicates that repetitive shallow dives, perhaps as a consequence of an extended avoidance reaction to sonar sound, can indeed pose a risk for DCS and that this risk should increase with the duration of the response. If the model is correct, then limiting the duration of sonar exposure to minimize the duration of any avoidance reaction therefore has the potential to reduce the risk of DCS. Key words: beaked whales, deep divers, sonar, avoidance reaction, nitrogen saturation, bubble growth, decompression sickness, stranding.
The biology and behaviour of a free-living population of black rats (Rattus rattus)
Rosalie F. Ewer
- A population of wild Rattus rattus living in the roofs of the laboratory buildings was studied by supplying food every evening and watching the behaviour of the animals at the feeding place. Some observations were also made on caged animals. The rats were predominantly of the black rattus variety but white-bellied greys appeared now and then. In breeding tests the grey colour behaved as though determined by a single recessive gene. The study covered two periods of approximately 9 months each, separated by an interval of 3 months during which a reduced quantity of food was provided and the rat population underwent a major decline. During the two periods of richer feeding the population first increased and then stabilized at a level where the animals remained in good condition and there was no starvation. In the first 9-month period, stabilization was achieved by emigration of young adults who colonized neighbouring buildings. Towards the end of the second period, stabilization was achieved by limitation of breeding. The rats accepted a wide variety of foods, including meat, and a number of instances of predation were seen. Small vertebrates as well as insects were killed and eaten. Small pieces of food were usually eaten in situ but large bits were taken up to the nests in the roof. Such differential treatment in relation to size may be a factor of some importance in the evolution of hoarding. The rats visiting the feeding place formed a unit with a definite social structure. A single dominant male and never more than one, was always present and in certain circumstances a linear male hierarchy was formed. There were usually two or three mutually tolerant top ranking females who were subordinate to the top male but dominant to all other members of the group. Within the group attacks were directed downwards in the social scale. An attacked subordinate either fled or appeased and serious fights therefore did not develop. The most essential component of the appease. ment appeared to be a mouth to mouth contact which may be derived from the infantile pattern of 'mouth suckling'. Appeasement permitted superior rats to maintain their status without the necessity of carrying attacks on subordinates to the point where actual hurt was inflicted. A group territory round the feeding place was defended against interlopers. Both sexes took part in chasing out intruders but since males showed inhibition in attacking females, the exclusion of strange females was due principally to the activities of the home females. The point at which pursuit of an intruder stopped was regarded as the territorial boundary. This was also the limit beyond which a group member would not allow himself to be chased but it was not a prison wall. When agonistic tendencies were not aroused the animals no longer always I turned back at the boundary and foraging beyond its limits allowed them to become familiar with an area larger than the territory. Although intruders were normally driven out, it was occasionally possible for a particularly determined animal of either sex to force its way in and ultimately become a member of the group. The patterns of behaviour seen are described, particularly those concerned with hostile encounters and with mating. Scent marking with urine drip trails was not seen but adults of both sexes marked by rubbing the cheeks and ventral surface on branches. The circumstances in which tooth gnashing was heard suggest that this behaviour is not a form of threat but a response to unfamiliar auditory or visual stimuli. There was some evidence that it functioned as an alarm signal within the group. Pilo-erection and a gait or posture with the hind legs much extended ('stegosauring') are considered to function as threats. Pilo-erection occurred in situations where there was little to suggest conflict and is considered to represent a form of threat which has undergone emancipation. Various forms of displacement and ambivalent behaviour were seen. Rapid vibration of the tail occurred in thwarting situations, either during mating or when a defeated opponent suddenly vanished. There was no evidence that it acted as a signal. The common form of amicable behaviour was social grooming. Another amicable action was sitting together with the bodies in contact. Animals reared in cages remained shy and wary and even hand reared young developed the usual alarm responses to movement and noises. Females had their first litters at ages of 3 to 5 months. For first litters gestation periods were 21 to 22 days but in females that were simultaneously lactating they ranged from 23 to 29 days. Eight was the commonest litter number and ten the highest recorded. At birth the tail is very much shorter than the body but has outstripped it by the time the youngster emerges from the nest. This was found to be the result of a period of extremely rapid tail growth immediately preceding emergence. In Rattus norvegicus the peak in tail growth rate was found to be later and less striking. The difference is interpreted as related to the importance of the tail in climbing in the more arboreal R. rattus. During the second week of life an edge response (retreat from a declivity) and a clinging response made their appearance: these have the function of preventing accidental falls from a nest situated above ground level. Mouth suckling was seen only during a period of a few days towards the end of lactation. Play developed within a few days of emergence from the nest: locomotor and fighting play were the common types. Older animals occasionally joined in play with the young. In problem solving tests, first solutions were not insightful but once a solution had been found, the successful technique was at once adopted and subsequently perfected. There was no evidence of learning by imitation but the rats did learn from each other's behaviour that food could be obtained at a certain location and thus the solution of a problem by one rat accelerated its independent solution by others. The reasons for the differences between the behaviour of the free living population and the caged animals studied by other authors are discussed.
I depositi würmiani del Riparo Tagliente ; [Mit engl. u. franz. Zsfassung] / Bartolomei, G. u.a. [Mitarb.]
- Gli Autori presentano i risultati preliminari dello studio interdisciplinare (geostratigrafia e paleopedologia; palinologia; malaccfaune; faune mammologiche; industrie; datazioni raiometriche) dei depositi würmiani, fortemente antropizzati, del Riparo Tagliente in Valpantena (Monti Lessini). I depositi più antichi, riferibili al I Pleniglaciale wiirmiano e alla parte iniziale del Würm medio, contengono industrie del Paleolitico Medio e della fase arcaica del Paleolitico Superiore (Aurignaziano a dufours). Una fase erosiva, la deposizione di ghia:e fluviali all'esterno del riparo e fenomeni di geliflusso sono riconducibili al II Pleniglaciale würmiano. I depositi più recenti, riferibili al Tardiglaciale (dal Dryas antico all'oscillazione di Alleriöd), hanno dato industrie dell'Epigravettiano italico finale e altri resti di occupazione antropica del riparo (strutture di abitato, oggetti ornamentali, una sepoltura, opere d'arte). Le sequenze di industrie musteriane cd epigravcttianc del Riparo Tngliente costituiscono attualmente il punto di riferimento fondamentale per lo studio dei complessi del Paleolitico Medio e della fine del Paleolitico Superiore nell'Italia nordorientale.
Contributo alla conoscenza biologica e morfologica di alcuni Lamellicorni fillofagi (Amphimallus assimilis obscurus Brenske; Haplidia etrusca Kraatz.; Anoxia matutinalis suturalis Rttr.), e descrlzione di una nuova specie di Acaro (Coleolaelaps Inopinatus Grnd.)
Die schweizerische anthropologische Aufnahme im Lichte der polnischen Untersuchungsmethoden
Diversity and distribution of type specimens deposited in theInvertebrate section of the Museum of Zoology QCAZ,Quito, Ecuador
David A. Donoso
Rafael E. Cárdenas