Coelomic Transport and Clearance of Durable Foreign Bodies by Starfish (Asterias rubens).
Echinoderms have excellent healing and regeneration abilities, but little is known about how they deal with the related challenge of durable foreign bodies that become lodged within their bodies. Here we report a novel mechanism for foreign body elimination in starfish. When injected into the arm of a starfish, passive integrated transponder tags and magnets of similar dimensions are eliminated at a rate approximating 10% per day. These objects are forcefully ejected through the body wall at the distal tip of an arm. Ultrasound images reveal that foreign bodies are moved within the body cavity, and tracking of magnets injected into starfish suggests that the movements are haphazard rather than directed. Constrictions of the body wall near the foreign object are the likely mechanism for this transport process. Open questions include the ecological relevance of this behavior, why clearance occurs through the distal tips of the arms, the neurological and muscular control of this behavior, what other animals use this mechanism, and the range of objects starfish can eliminate in this way.
Department of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark; and.
Trine Bottos
TB
Olsen
Department of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark; and.
Frederik Ekholm Gaardsted
FE
Christensen
Department of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark; and Max-Planck Odense Center on the Biodemography of Aging, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
Kim
K
Lundgreen
Department of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark; and Max-Planck Odense Center on the Biodemography of Aging, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
Paul H
PH
Dunn
Department of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark; and Max-Planck Odense Center on the Biodemography of Aging, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark levitis@biology.sdu.dk.
Daniel A
DA
Levitis
D000818:Animals; D047271:Asterias / Q000502:physiology*; D005547:Foreign Bodies; D009119:Muscle Contraction