Solaster dawsoni
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Solaster dawsoni eats the starfish Hippasteria spinosa |
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| Scientific name | ||||||||||||
| Solaster dawsoni | ||||||||||||
| Verrill , 1880 |
Solaster dawsoni is a type of sun star from the order of the valve stars (Valvatida), which iswidespreadin the North Pacific .
features
Solaster dawsoni has a very large central disk on which 8 to 16 (usually 11 or 12) long, tapering arms sit, often with the tips of their arms bent upwards. The skin on the top is smooth and usually red, orange, gray, or pale brown, sometimes with even paler spots.
Reproduction
Like most starfish, Solaster dawsoni is segregated. The females and males give off their germ cells between March and June, which rise to the surface of the sea. There the egg cells are fertilized by the sperm. Larvae develop that live on the abundant yolk of the eggs and do not eat anything. As part of the zooplankton, they drift with the ocean currents. Later they sink to the seabed, where they undergo the metamorphosis into young sun stars.
Distribution and occurrence
Solaster dawsoni lives in the North Pacific at depths of up to 420 m, where it occurs from Japan , China and Siberia via Alaska along the North American Pacific coast to California . It often occurs on rocks, but can also be found on other surfaces. There are two subspecies: S. d. arcticus Verrill, 1914 in East Asia and S. d. dawsoni Verrill, 1880 in North America.
nutrition
Solaster dawsoni is a carnivore that feeds primarily on other starfish . In British Columbia about half of its prey consists of leather stars ( Dermasterias imbricata ), which show an escape reaction , but are slower than Solaster dawsoni . Other species like Stylasterias forreri and Orthasterias koehleri defend themselves with arm movements and with the help of their pedicellariums , so that they sometimes escape. Pteraster tesselatus inflates itself in defense and secretes a slime, which makes it difficult for Solaster dawsoni to seize the prey starfish. The very large starfish Pycnopodia helianthoides also takes flight from Solaster dawsoni and sometimes has to throw off an arm to save itself. Other prey animals include sea cucumbers , including Cucumaria lubrica and Eupentacta quinquesemita . The nudibranch snail Tritonia festiva is also attacked in laboratory tests , but it usually escapes the sun star by swimming away. Even cannibalism comes at Solaster dawsoni ago.
literature
- Howard M. Feder: Asteroidea , in: Robert Hugh Morris, Donald Putnam Abbott, Eugene Clinton Haderlie: Intertidal Invertebrates of California . Pp. 117–135, here p. 122, 8.7: Solaster dawsoni Verrill, 1880 . Stanford University Press, 1st ed., Stanford (CA, USA) 1980.
Web links
Individual evidence
- ↑ a b c d Morning sun star: Solaster dawsoni . In: Sea stars of the Pacific Northwest . 2011. Archived from the original on September 9, 2012. Info: The archive link was automatically inserted and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved September 21, 2012.
- ↑ a b c d Solaster dawsoni . In: Race Rocks Taxonomy . Retrieved September 21, 2012.
- ^ RL Dorit, Walker, WF, Barnes, RD: Zoology . Saunders College Publishing, 1991, ISBN 0-03-030504-7 , p. 782.
- ↑ Sunflower star: Pycnopodia helianthoides . In: Sea stars of the Pacific Northwest . 2011. Archived from the original on September 9, 2012. Info: The archive link was automatically inserted and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved September 24, 2012.
- ^ Howard M. Feder (1980), p. 122.
