Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Patterns of Whole Colony Prey Capture in the Octocoral, Alcyonium siderium

Mark R. Patterson
Biological Bulletin
Vol. 167, No. 3 (Dec., 1984), pp. 613-629
DOI: 10.2307/1541414
Stable URL: http://www.jstor.org/stable/1541414
Page Count: 17
  • Subscribe ($19.50)
  • Cite this Item
Patterns of Whole Colony Prey Capture in the Octocoral, Alcyonium siderium
Preview not available

Abstract

Colonies of a boreal octocoral, Alcyonium siderium, preferentially catch prey on specific regions of the colony at certain flow speeds of low turbulence. Colonies feeding on brine shrimp cysts capture prey preferentially on the upstream side of the colony under low flow conditions (2.5 cm· s-1). At intermediate flow speeds (9.0 cm· s-1), prey capture is uniformly distributed around the circumference of the colonies, while at higher flow speeds (19.0 cm· s-1), prey capture again becomes asymmetric and downstream polyps capture the most prey. At higher levels of free-stream turbulence, these asymmetric prey capture distributions around the colony disappear; in the vertical direction, prey capture is asymmetric over the surface of the colony at all flow speeds tested, with polyps nearer the top of the colony capturing the most prey only at the lowest speeds. Asymmetrical filtration results from (1) increasing mechanical deformation of polyps into an orientation unfavorable for prey capture with increasing flow speed, and (2) differential prey concentrations in the boundary layer of the colony in the downstream direction. For non-motile particles, the filtration performance of this passive suspension feeder appears governed only by the flow speed and turbulence, the mechanical behavior of the filter elements, and the motion of the particles in the boundary layer of the colony.

Page Thumbnails

  • Thumbnail: Page 
613
    613
  • Thumbnail: Page 
614
    614
  • Thumbnail: Page 
615
    615
  • Thumbnail: Page 
616
    616
  • Thumbnail: Page 
617
    617
  • Thumbnail: Page 
618
    618
  • Thumbnail: Page 
619
    619
  • Thumbnail: Page 
620
    620
  • Thumbnail: Page 
621
    621
  • Thumbnail: Page 
622
    622
  • Thumbnail: Page 
623
    623
  • Thumbnail: Page 
624
    624
  • Thumbnail: Page 
625
    625
  • Thumbnail: Page 
626
    626
  • Thumbnail: Page 
627
    627
  • Thumbnail: Page 
628
    628
  • Thumbnail: Page 
629
    629