Wolfgang Chritstian Pfeiffer

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1. In mehr als 100 Versuchen an ebensovielen Versuchsgruppen wurden mehrere tausend Kaulquappen von acht verschiedenen Anurenarten aus fünf Familien auf die Schreckreaktion hin untersucht. 2. Die von Erdkrötenkaulquappen, Bufo bufo, bekannte Schreckreaktion wurde auch für die Kaulquappen der Kreuzkröte, Bufo calamita, nachgewiesen. Dagegen fehlt die(More)
The change of state in the central nervous system ofGymnocorymbus ternetzi after detection of hypoxanthine-l(N)-oxide, hypoxanthine-3(N)-oxide, and of the alarm substance from conspecifics was measured quantitatively by means of the fishes' equilibrium behavior. The fish swam freely in a tiny cage, illuminated horizontally from one side. The change of the(More)
1. Die Welsfamilien Doradidae und Mochokidae erzeugen bei Belästigung durch Reiben eines dorsalen Knochenfortsatzes des Brustflossenstrahls in einer Gelenkrinne deutlich hörbare Laute. 2. Die Laute entstehen sowohl beim Vorbewegen als auch beim Zurückbewegen der Brustflosse. 3. Das Abspreizen der Brustflosse geht langsamer vor rich und der Laut ist(More)
 Vacuolar ATPase (EC 3.6.1.3) and PPase (EC 3.6.1.1) were studied in suspension cells and seedlings from spruce [Picea abies (L.) Karst. Proton transport activity and uncoupler (1 µM nigericin) stimulated substrate hydrolysis were measured in tonoplast enriched membrane vesicles. In suspension cells the vacuolar PPase exhibited 1.8-fold activity of the(More)
Seventy perch (Perca fluviatilis) caught in Lake Constance at Langenargen in May 1990 were examined for parasites. The frequency distributions of the eyefluke Diplostomum spathaceum (Rudolphi, 1819), and the tapeworms Proteocephalus percae (Müller, 1780) and Triaenophorus nodulosus (Pallas, 1781) fitted closely to a negative binomial. Only a few fish were(More)
FRISCH, 19411, w e cal l s u b s t a n c e s w h i c h c o m m u n i c a t e the presence of danger, ' a larm substances' (Schreckstoif), provided tha t they are produced by members of the same species. We define the communication of danger by observing the responses of animals to the substance under investigation. These responses to a larm substance m a y(More)
Perch (Perca fluviatilis L.) caught in Lake Constance every 2 months over a period of 3 years below six towns or villages (Langenargen, Nonnenhorn, Rorschach, Romanshorn, Bottighofen, and the Lake of Überlingen) were examined for parasites. In contrast to Diplostomum spathaceum (Rudolphi, 1819) and Tylodelphysclavata (Nordmann, 1832), Bunoderaluciopercae(More)
Commercial fish (perch, roach, bream, dace, and burbot) were caught below Langenargen in 1988–1990. Their infestation with cestodes and digenean trematodes was studied. The results were compared with earlier data. The infestation of perch with Diplostomum spathaceum and Ichthyocotylurus variegatus noted in 1988–1990 had increased as compared with that(More)
The histochemical studies of the alarm substance cells from Phoxinus phoxinus and Morulius chrysophakedion (Cyprininae, Cyprinidae, Cypriniformes, Ostariophysi) are in total agreement with the results of the ultrastructural investigations. Perinuclear ribosomes, mitochondria, and a golgi complex are demonstrated. A tubular network radiates from the golgi(More)
1. The skin, mainly the mucus cells, the superficial neuromasts, the taste buds, and the organs of Fahrenholz were studied by light microscopy in all recent genera of the Dipnoi and the Brachiopterygii. 2. The Dipnoi have one type of large mucus cell in the epidermis. The Brachiopterygii show two different types of mucus cells: large so-called “club-cells”(More)