Rose Star

Crossaster papposus 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)

Other Physical Features: ectothermic

Crossaster papposus 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)

Aquatic Biomes: coastal

North Atlantic and Pacific Coasts: (Himmelman and Dutil, 1991) One can find C. papposus from 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)

Biogeographic Regions: atlantic ocean (Native ); pacific ocean (Native )

In its habitat, C. papposus is considered to be the dominant predator, along with Solaster endece, another species of predacious sea star. As a dominant predator, C. papposus 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. C. papposus has often been observed feeding on urchins, as well as on numerous other invertebrates, including echinoderms, bivalves, cnidarians, and tunicates. (Coleman, 1991) Cannibalism in C. papposus is rare, observed only after long starvation in captivity. (Sloan, 1984)

Among the most beautiful of echinoderms, C. papposus 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)

Unfortunately, information regarding the economic importance of C. papposus and 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, C. papposus clearly has a significant impact on its ecosystem.

Crossaster papposus, 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 C. papposus tend to prefer sediment bottoms of the sea. Upon growing to 5cm in diameter, C. papposus 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, C. papposus 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)

The common sunstar is named after the fact that it looks like a sun with its 8 to 14 arms. Its colorful, sunny appearance makes you think it has a nice character, but nothing is farther from the truth. It is a fearsome predator, which scares the daylights out of common starfish and other smaller marine animals. The common sunstar is quite fast for a starfish, reaching top speeds of 70 centimeters per minute. There are films where you see how brittle stars and sea urchins run away as soon as a sunstar is in the vicinity. If they are not fast enough, they are inevitably consumed.

Varied.

Geographical Range: Bering Sea to Puget Sound; Arctic Ocean, North Atlantic Ocean, North Sea, western Baltic sea

How to Distinguish from Similar Species: Solaster stimpsoni and S. dawsoni have much smaller central disks in relation to their total diameter and do not have the abundant aboral spines nor this coloration. Pycnopodia helianthoides has more rays, grows larger, and has abundant pedicellariae, plus its rays are very flabby.

This many-rayed seastar has a broad central disk and 8-16 rays, has abundant scattered spines on the aboral surface but no pedicellariae. Its color is a rose-red with light pink or white. Up to 30 cm diameter.

Depth Range: Extremely low intertidal to 1200 m. Mostly subtidal.

Biology/Natural History: Diet includes sea pens, nudibranchs such as Archidoris odhneri and Coryphella sp, the scallops Chlamys hastata and C. rubida, bryozoans, and tunicates. Has been known to attack the seastar Evasterias troschelii and Leptasterias sp. Predators include the seastars Solaster dawsoni and Pycnopodia helianthoides. May have the symbiotic polychaete worm Arctonoe vittata. This species can move relatively fast for a seastar--up to 70 cm/minute. Spawns March to April. Juveniles often cluster subtidally in masses of the tubedwelling polychaete Phyllochaetopterus prolifica. Grow slowly--maximum size is achieved after about 10 years.

The common sunstar is a species of sea star (aka starfish) belonging to the family Solasteridae. It is found in the northern parts of both the Atlantic and the Pacific Oceans.

Direct development? Winter

Arctic to Gulf of Maine

From low intertidal to more than 200 m depth, mainly on coarse sand and gravel, all round the British Isles

bathyal, infralittoral and circalittoral of the Gulf and estuary

Known from seamounts and knolls