North Atlantic and Pacific Coasts: (Himmelman and Dutil, 1991) One can findfrom Alaska to Puget Sound, from the Artic to the Gulf of Maine. (MConnaughey and McConnaighey, 1985) It is common in British waters and in eastern Maine and can often be found in the lower intertidal zone from the Eastport area northward. (Hayward and Ryland, 1995)
is found on rock bottoms, ranging from the low tide line to approximately 1080' (329m) deep. (McConnaughey and McConnaughey, 1985) It is tolerant of strong sunlight. (Coleman, 1991)
ranges from 8" to 14" in diameter. It has many arms (between 8 and 14) the length of one-half its radius. It is scarlet on top with concentric bands of white, pink, yellow, or dark red, and it is white on the underside. Its entire upper surface is sparsely covered with brushlike bristles. (McConnaughey and McConnaughey, 1985) These bristles, called pseudopaxillae, consist of bundles of fine spines atop short stumps. The mouth area is bare, and it has two rows of sucker-tipped sensory tube feet. (Gosner, 1978)
, like most sea stars, has separate sexes, and fertilization is external. (Hickman and Roberts, 1995) Sexual reproduction produces lecithotropic larva in late winter. One-year-old individuals measure 1.8 to 4.0 cm in diameter, and there is a 2 cm annual growth increment during the following few years. (Himmelman and Dutil, 1991) Juvenile tend to prefer sediment bottoms of the sea. Upon growing to 5cm in diameter, migrates to shallow water (4-8cm in diameter) and then, with increasing size, it gradually moves to greater depths. (Himmelman and Dutil, 1991) Like other sea stars, can regenerate injured or missing arms, as long as a portion of the central disc, where the arms converge, is intact. (Hickman and Roberts, 1995)
is highly mobile. Large individuals can cover distances of >5 meters in 12 hours. (Himmelman and Dutil, 1991) has been found to disperse widely in order to forage for its mobile prey. As a dominant predator high in its food web, has also been influential in dispersal of competitors, affecting distribution of these other asteroid species. (Sloan, 1979) When hungry, maeks contact with its prey, retracts its sensory tube feet, then protracts its tube feet to gain height over the prey. This enables it then to "pounce" on its victim, whereupon swallows small prey whole or covers large, sessile prey with its body and engulfs it with its evertible stomach. (Coleman, 1991) (McConnaughey and McConnaughey, 1985) (Sloan, 1980) Defense responses of are not much studied, but it has been observed that these starfish restract their sensory tube feet as a defensive response. (Sloan, 1980)
Chemoreception abilities have also been observed in. It shows a wide variety of responses to crude extract of prey species and conspecifics. has the olfactory (distance chemoreception) ability to sense whole, live potential prey and conspecifics. (Sloan and Northway, 1982)
In its habitat,is considered to be the dominant predator, along with Solaster endece, another species of predacious sea star. As a dominant predator, plays an important role in determining community structure. (Himmelman and Dutil, 1991) Its abundance and frequent predatory activity suggests that it belongs to an important predatory guild. has often been observed feeding on urchins, as well as on numerous other invertebrates, including echinoderms, bivalves, cnidarians, and tunicates. (Coleman, 1991) Cannibalism in is rare, observed only after long starvation in captivity. (Sloan, 1984)
Unfortunately, information regarding the economic importance ofand its value to humans is either not well-studied, not well-documented, or simply inaccessible. As an aggressive predator high on its food web and as an agent of dispersal of both its competitors and prey, clearly has a significant impact on its ecosystem.
Among the most beautiful of echinoderms,is a bright spot of color in North Atlantic and Pacific waters. It can be readily recognized and differentiated from other sea stars in that it has several more than the standard number or tube feet (five). (Hickman and Roberts, 1995)
Heather Grush (author), University of Michigan-Ann Arbor.
the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
the nearshore aquatic habitats near a coast, or shoreline.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
the area in which the animal is naturally found, the region in which it is endemic.
Coleman, N., 1991. Encyclopedia of Marine Animals, Harper Collins Publishers, New York, 161.
Gosner, K.L., 1978. Atlantic Seashore: Peterson Field Guides. Houghton Mifflin Company, New York, 260-1.
Haywood, P.J., and Ryland, J.S., 1995. Handbook of the Marine Fauna of Northwest Europe, Oxford University Press, 668.
Hickman, C.P., and Roberts, L.S., 1995. Animal Diversity, Wm. C. Brown Communications, Inc., Dubuque, IA, 228-232.
Himmelman, J.H., and Dutil, C., 1991. "Distribution, population structure and feeding of subtidal seastars in the northern Gulf of St. Lawrence, Marine Ecology Press Series, Vol. 76, 61-72.
McConnaughey, B.H., and E., 1985. Pacific Coast: The Audubon Society Nature Guides, Chanticleer Press, New York, 373, 462.
Sloan, N.A., 1984. "Interference and Aggregation: Close Encounters of the Starfish Kind, Ophelia, Vo. 23, No. 1, 23-31.
Sloan, N.A., and Northway, S.M., 1982. "Chemoreception by the Asteroid Crossaster papposus," Journal of Experimental Marine Biology and Ecology, Vol. 61, No. 1, 85-98.
Sloan, N.A., 1980. "The arm curling and terminal tube-foot responses of the asteroid Crossaster papposus," Journal of Natural History, Vol. 14, No. 4, 469-482.
Sloan, N.A., 1979. "Starfish encounters: An experimental study of its advantages," Experientia (Basel), Vol. 35, No. 10, 1314-15.