Directional Movement of Urticina crassicornis in the Presence of a Conspecific

Abstract

Many sea anemones aggregate, including Urticina crassicornis (common name: the Christmas or painted anemone). This species occurs on the docks and shores of the Friday Harbor Laboratories as well as the intertidal zones around San Juan Island, Washington. There are many benefits to grouping behavior, such as protection from predators, and propinquity to other reproductive conspecifics. To test wether U. crassicornis migrates in the direction of conspecifics, two anemones of this species were placed in different sections of a Y-maze. The distance traveled by both anemones was recorded. Urticina crassicornis does move; however the context of that movement is unclear. The results are especially interesting in the context of potentially adaptive behavior of anemones as a phylogenetic group.