Vertikalverteilung von Nematoden in Beständen nordadriatischer Sargassaceen
In: Helgoländer Wissenschaftliche Meeresuntersuchungen. Biologische Anstalt Helgoland: Hamburg. ISSN 0017-9957, meer
Ook verschenen in:Kinne, O.; Aurich, H. (Ed.) (1967). Vorträge und Diskussionen. Erstes Europäisches Symposion über Meeresbiologie = Papers and discussions. First European Symposium on Marine Biology = Rapports et discussions. Premier symposium européen sur biologie marine. European Marine Biology Symposia, 1. Helgoländer Wissenschaftliche Meeresuntersuchungen, 15(1-4). 669 pp., meer
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| Abstract |
The nematode fauna of Cystoseira-growths in the upper sublittoral of a rocky shore in Yugoslavia shows a stratification in its composition, which varies according to growth-form and exposition. Typical faunas on the stems, the highly branched parts and the free-waving tips were distinguished. Thick epigrowth shows a marked influence on the composition of the nematode fauna. The effects of the factors (1) water movement, (2) sediment content, (3) substrate structure and (4) nutrition are discussed. The decrease of water-movements measured ranges from decimetres outside the growth to millimetres within the epigrowth. A graph of the isokines in aCystoseira-growth is given. Sediment content is correlated to populationdensity in parts of comparable growth-form. Minute structures of the algae surface are responsible for the possibilities of locomotion; the stable interstitial space within the epigrowth of calcareous red algae favours aberrant types of locomotion. Large forms find suitable conditions in the colonies of Bryozoa growing at the stems. The distribution of feeding-types (Wieser 1953) shows a characteristic pattern with the epigrowth-feeders mainly at the tips of the thalli, predators and deposit-feeders dominating at the bases. A species with a buccal cavity of the predator type,Enoplus meridionalis, seems to change from epigrowth-feeder as a juvenile (living among the tips) to predator as an adult (only to be found at the bases). |
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