Animal Diversity Web

Ge­o­graphic Range

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

Habi­tat

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

Phys­i­cal De­scrip­tion

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

Re­pro­duc­tion

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)

Be­hav­ior

C. pap­po­sus is highly mo­bile. Large in­di­vid­u­als can cover dis­tances of >5 me­ters in 12 hours. (Him­mel­man and Dutil, 1991) C. pap­po­sus has been found to dis­perse widely in order to for­age for its mo­bile prey. As a dom­i­nant preda­tor high in its food web, C. pap­po­sus has also been in­flu­en­tial in dis­per­sal of com­peti­tors, af­fect­ing dis­tri­b­u­tion of these other as­ter­oid species. (Sloan, 1979) When hun­gry, C. pap­po­sus 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 C. pap­po­sus 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 C. pap­po­sus 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 C. pap­po­sus. It shows a wide va­ri­ety of re­sponses to crude ex­tract of prey species and con­specifics. Crossas­ter pap­po­sus has the ol­fac­tory (dis­tance chemore­cep­tion) abil­ity to sense whole, live po­ten­tial prey and con­specifics. (Sloan and North­way, 1982)

Food Habits

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)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

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.

Other Com­ments

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)

Con­trib­u­tors

Heather Grush (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

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.