Meeting Abstract
To cope with the forces of wave activity, organisms living in the intertidal have developed a variety of mechanisms to stay in place. Metridium farcimen (white-plumed sea anemone) can withstand wave action by strongly attaching to solid substrates. However, not much is known about the attachment forces this animal utilizes to hold onto the substrate. M. farcimen attach to a substrate by secreting an adhesive glue from the basal foot. Limpets, another intertidal invertebrate, attach to substrate using glue and the additional force of suction. In this study, we explore the possibility of suction and glue working in unison to attach M. farcimen to substrate. Since no suction can occur on surfaces with holes, our experiments were performed using acrylic glass substrates with and without holes. Specimens attached to the substrate were placed in a small water tank where they were connected to the sensor of a mechanical testing machine. The machine recorded the force required to remove the anemone from the substrate. The pull-off forces and the area of each anemone’s basal foot were used to calculate tenacity. Specimens attached to solid substrates with a tenacity of 9.36 kPa ± 5.35 (mean ± s.d.). This is comparably less than other intertidal species such as limpets or clingfish. On holed substrates tenacity was 5.48 kPa ± 2.31 (mean ± s.d.). These data imply that suction is a component of M. farcimen attachment, but glue plays the dominant role. Attachment site selection behaviors were also examined. When given the option of attaching to acrylic glass substrates with and without holes, M. farcimen showed no preference for either substrate. We conclude that suction contributes to attachment in M. farcimen, but does not seem to influence attachment site selection under normal conditions.
