- Ecology And Behaviour
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The mode of dislocation ofAstropecten aranciacus
Die Dislokationsweise vonAstropecten aranciacus
Helgoländer wissenschaftliche Meeresuntersuchungen volume 24, pages 151–156 (1973)
Kurzfassung
An der Nordküste Sardiniens wurden auf einer Sandfläche in 8 m Tiefe Exemplare des SeesternsAstropecten aranciacus einzeln während einer 30minütigen Beobachtungsdauer verfolgt. Jede Minute steckte ein Taucher eine numerierte Steckmarke eine Handbreite hinter dem sich fortbewegenden Seestern in den Sand. Nachher wurden die Wege vermessen. Auf diese Weise wurden 23 Seesterne verfolgt. Die Auswertung der Beobachtungsdaten erbrachte Aufschlüsse über Wegrichtung und Richtungsänderung, Geschwindigkeit der Fortbewegung, Häufigkeit und Dauer des Anhaltens, Einfluß der Sandkorngröße auf Haltefrequenz und Geschwindigkeit der Fortbewegung und Einfluß des Verlaufs und der Höhe von Rippelmarken auf die Wegrichtung.
Summary
1. The mode of dislocation of the sea starAstropecten aranciacus was investigated on 23 individuals at the NE-coast of Sardinia. All were small to medium-sized representatives of the species; their radius (R) varied between 5 and 15 cm. The observations were carried out on 2 level sediments with different sand-grain diameter. Each sea star was followed for 30 min and its locations were recorded every minute.
2.A. aranciacus does not move continuously. It stops intermittently for an average duration of 2 minutes. On coarse grained sand, stops occur more frequently than on fine grained sand.
3. The average distance travelled in 30 min was 3.7 m on fine sand, 1.6 m on coarse sand. Including the stops, the cruising speed varied mostly between 0 and 20 cm/min on fine sand, and between 0 and 10 cm/min on coarse sand.
4. Generally, the observed paths were all or partially straight. In accord with this, the ratio W/D between the distance travelled (W) and the shortest between the starting and end position (D) was smaller than 2 for most animals.
5. Small ripple marks (on fine sand) do not seem to influence the direction of dislocation. Single observations indicate, however, that more pronounced ripple marks (on coarse sand) may have an influence.
Literature cited
Burla H., Ferlin, V., Pabst, B. &Ribi, G. 1972. Notes on the ecology ofAstropecten aranciacus. Mar. Biol.14, 235–241.
Feder, H. &Christensen, A. M., 1966. Aspects of asteroid biology. In: Physiology of Echinodermata. Ed byR. A. Boolootian. Wiley, New York, 87–127.
Galtsoff, P. S. &Loosanoff, V. L., 1939. Natural history and method of controlling the starfish. Bull. Bur. Fish., Wash.49, 73–132.
Loosanoff, V. L., 1958. Underwater studies of starfish behaviour and evaluations of control methods. Bull. biol. Lab., Milford22, 1–5.
Romanes, G. J. &Ewart, J. C., 1881. Observations on the locomotor system of Echinodermata. Phil. Trans. R. Soc.172, 829–885.
Weber, E., 1965. Eine fakultative Freßgemeinschaft von Fischen und Stachelhäutern. Z. Tierpsychol.22, 567–569.
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Ferlin, V. The mode of dislocation ofAstropecten aranciacus . Helgolander Wiss. Meeresunters 24, 151–156 (1973). https://doi.org/10.1007/BF01609507
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DOI: https://doi.org/10.1007/BF01609507