Behavior Complexity in the righting behavior of the starfish Asterina pectinifera

Righting behavior is one of the best known behavior patterns of starfish, and it has attracted researcher's interests for more than one hundred years (Jennings, 1907; Ohshima, 1940; Reese, 1966; Polls and Gonor, 1975; Lawrence and Cowell, 1996). Righting in the shortest possible time may reduce the risk of being swept away in surge or attack by predators. Conflicts between arms should be avoided to minimize righting time, which could be accomplished by using specific leading arms. Thus, it could be beneficial for starfish if they could learn to right themselves. Previous studies have explored the possibility that starfish can learn to use specific arms as the leading arms and/or to complete righting in shorter times, but the majority of these have produced negative results (Jennings, 1907; Ohshima, 1940; Reese, 1966). However, recent studies do not focus on the behavioral aspect per se, but deal with the righting behavior as an indication of stress (Diehl et al., 1979; Lawrence & Cowell, 1996; Kashenko, 2003).