Long Beach Aquarium of the Pacific, Long Beach, CA April 18, 2003

The sea star, Astrometis sertulifera. According to Feder (1980) this southern California was studied "in classic behavior studies by Jennings (1907), misidentified as Asterias forreri, at La Jolla. The animals are capable of fairly rapid movement, when transferred to lab aquaria the 'explore' the new area before settling down. They avoid strong light and generally come to rest in shaded areas; increasing the light stimulates a temporary increase in movement. [...] Jennings was able to train some individuals to use certain arms habitually in righting, but found that the sea stars were not apt pupils; habit formation was slow and the effects of training lasted at most a few days. He remarked, somewhat pessimistically, 'It would now be possible...to develop...educational methods for the starfish. By begininning with young specimens, it is probable that striking results would be reached. Such an investigation would require steady application to extremely dull and tedious work, for a long period.' Remarkable among Jennings's findings was the discovery that the forceps-like pedicellariae can be used to capture active prey. Large cussions bearing numerous pairs of these tiny pincers... Jennings showed that small crabs, sand crabs (Emerita analoga) and even fishes as large as the sea star itself are captured and held by the pedicellariae and later transferred to the mouth and eaten... Astrometis gives an avoidance resose to the predatory sea star Heliaster kubinijii, whose range it overlaps with in Baja California; and in laboratory aquaria, Heliaster eats Astrometis."

Feder, H. M. 1980. Chapter 8 - Asteroidea: The sea stars. Pp. 117-135, in (R. M. Morris, D. P. Abbott and E. C. Haderlie, eds.) Intertidal Invertebrates of California. Stanford Univ. Press, Palo Alto.

Jennings, H. S. 1907. Behavior of the starfish, Asterias forreri de Loriol. Univ. Calif. Publ. Zool. 4: 53-185.

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Image by D.J. Eernisse © 2003