Yellow sun star
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Yellow Sun Star ( Solaster endeca ) |
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| ( Linnaeus , 1771) |
The yellow sun star , violet sun star or purple sun star ( Solaster endeca ) is a type of sun star from the order of the valve stars (Valvatida), which is represented circumboreally in the North Atlantic and North Pacific .
features
The purple sun star usually has 7 to 10, sometimes up to 13 round arms and reaches a diameter of about 20 cm, occasionally up to 40 cm. The central disk is smaller than that of the common sun star , so that the arms appear longer. The top of the common sun star is orange to deep purple, the tips of the arms are usually lighter and curved upwards so that the pale underside is visible. The skin on the top is comparatively smooth; so there are no pedicellariums . The calcareous plates in the skin are densely covered with paxillae (umbrella-like plates). Between the plates there are groups of two to three skin gills (papules). The rows of plates on each edge on the underside of the ambulacral furrow carry two to three thorns and several rows of shorter spines. The suction feet are in two rows.
Reproduction
Like most starfish, the purple sun star is sexually separate. In spring, the female releases thousands of egg cells over the course of a week, which rise to the surface of the water and are fertilized there by the male's sperm. The resulting larvae, swimming freely with cilia , feed on yolk and become somewhat sluggish after three days. They develop a pair of larval arms and after about 18 days they sink to the ground and attach themselves with a sucker. After 6 more weeks, the metamorphosis is complete and young sun stars begin to move.
Distribution and occurrence
The purple sun star can be found in the North Atlantic including the North Sea and the North Pacific . It occurs off Greenland , on the North American Atlantic coast from Canada to the Gulf of Maine . It is an endangered species in the Baltic Sea . It lives on the Pacific coast of North America from Northern Alaska to Puget Sound .
The purple sun star lives on mud, sand or gravel to a depth of about 450 m. It occurs both in the surf and in sheltered places.
nutrition
The purple sun star is a carnivore that feeds on starfish , sea cucumbers , sea urchins , mussels and sea anemones , among other things . The prey is swallowed as a whole, or - in the case of larger prey and sessile animals - the stomach is pulled over it.
literature
- Sven Gehrmann: The fauna of the North Sea - lower animals & vertebrates . Epubli, Berlin 2011. pp. 153f.
- James F. Gemmill (1910): The development of the starfish Solaster endeca Forbes (1912) . Transactions of the Zoological Society of London.
- HG Hansson (2001): Echinodermata . In: MJ Costello et al. (Ed.): European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification . Collection Patrimoines Naturels 50, pp. 336-351.
- AM Clark, ME Downey: Starfishes of the Atlantic . Chapman & Hall Identification Guides, 3rd Chapman & Hall, London 1992. ISBN 0-412-43280-3
Web links
- Peter Jonas: Yellow sun star . Underwater world Baltic Sea
- MJ de Kluijver & SS Ingalsuo: Purple Sunstar (Solaster endeca) . Macrobenthos of the North Sea - Echinodermata. Marine Species Identification Portal.
- Sonia Rowley: Purple sun star - Solaster endeca . The Marine Life Information Network (MarLIN), Marine Biological Association of the United Kingdom, Plymouth 2007.
- BE Picton, CC Morrow: Solaster endeca (Linnaeus, 1771) . Encyclopedia of Marine Life of Britain and Ireland, 2015.
- World Register of Marine Species : Christopher Mah, Hans Hansson (2015): Solaster endeca (Linnaeus, 1771) . In: Christopher L. Mah (2015). World Asteroidea database.