Metridium farcimen show little to no preference for prey particle size

Abstract

The overabundance of one species in a particular area is typically bolstered by a biotic or abiotic factor that allows them to outcompete other species for space and resources. The undersides of the docks in the town of Friday Harbor and at the Friday Harbor Laboratories are overrun with white plumose anemones, Metridium farcimen. The sewage output in the town docks contains particulate matter, which the prey of M. farcimen may feed on. To determine if particulate matter contributes to M. farcimen abundance, I collected specimens from both locations, placed them in controlled tanks and exposed them to separated samples of zooplankton of varying sizes. The anemone did not show an overall preference for food particle size, although they did show a slight preference of 0.3 mm particles over 0.5 mm particles. It is possible that they are consuming all size classes of zooplankton that feed on sewage particulates.