| Astropecten irregularis | |
|---|---|
 | |
| Astropecten irregularis on sea bottom | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Asteroidea |
| Order: | Paxillosida |
| Family: | Astropectinidae |
| Genus: | Astropecten |
| Species: | A. irregularis |
| Binomial name | |
| Astropecten irregularis (Pennant, 1777) | |
Astropecten irregularis is a sea star of the family Astropectinidae. Common names include Sand sea star (A. i. pontoporeus). [1]
Starfishes of genus Astropecten live on mobile seabed (sandy, muddy or gravel seabed), and they remain largely buried under sediment during the day. During the late afternoon and the night, starfish go out to hunt mainly bivalve molluscs, which are their favourite prey. Astropecten irregularis is a very common species in all kind of mobile seabed from 1 to about 1,000 m deep. This species is active and easy to find during the night, sometimes it is possible to find it in the late afternoon.
This species lives in the Atlantic Ocean and in the Mediterranean, but the two populations show differences in superomarginal plates. In particular, the specimens of the Mediterranean have superomarginal plates devoid of spines (they are considered by some author as the subspecies Astropecten irregularis pentacanthus) while Atlantic populations are provided with one spine for each superomarginal plates (they are considered by some authors as the subspecies Astropecten irregularis irregularis) or more spines (they are considered by some authors as the subspecies Astropecten irregularis serratus and by some others as a variety of Astropecten irregularis irregularis). This starfish has a well-developed and raised superomarginal plates and the specimens in the Mediterranean are totally devoid of spines. The inferomarginal plates are short, thin, fine-spines, highly mobile and white colour. Astropecten irregularis doesn’t keep these spines rigid and parallel to each other as the other species do. The arms make up among them, at their base where they join the disc, a very clean corner. The colour of aboral side is pink homogeneous, often violet in towards the end of the arms and sometimes there are many small darker spots in the central disc. Sometimes it has a bulge on centre of the disc that is highly developed in this species. This bulge protrudes from the sediment where the animal is hidden and it has respiratory functions (called "aboral-cone”). Usually it has diameter of about 10–12 cm with a maximum of 19 cm. It's a very common species in all kind of mobile seabed from 1 to about 1,000 m deep. Usually this starfish can be distinguished easily and safely from the others species of Mediterranean for superomarginal plates devoid of spines and from colour. Sometimes it is confused with Astropecten aranciacus for the similar colour, but it’s always possible to distinguish the two species by a closer inspection of superomarginal plates and inferomarginal spines or by observations of the colour of the paxillae.
This sea star is a carnivore and feeds on molluscs, which it catches with its arms and then takes to the mouth. The prey is then trapped by the long, moving prickles around the mouth cavity.
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at 6,000 m (20,000 ft) below the surface.
The Echinasteridae are a family of starfish in the monotypic order Spinulosida. The family includes eight genera and about 133 species found on the seabed in various habitats around the world.
The Astropectinidae are a family of sea stars in the order Paxillosida. Usually, these starfish live on the seabed and immerse themselves in soft sediment such as sand and mud.
Astropecten is a genus of sea stars of the family Astropectinidae.
Astropecten polyacanthus, the sand sifting starfish or comb sea star, is a sea star of the family Astropectinidae. It is the most widespread species in the genus Astropecten, found throughout the Indo-Pacific region. The armspread is up to 20 cm (8 in). The specific epithet "polyacanthus" comes from the Latin meaning "many thorned".
Astropecten aranciacus, the red comb star, is a sea star of the family Astropectinidae. It is native to the east Atlantic Ocean and the Mediterranean Sea.
Astropecten bispinosus is a sea star of the family Astropectinidae from the Mediterranean Sea.
Astropecten platyacanthus is a sea star of the family Astropectinidae.
Astropecten jonstoni is a sea star of the family Astropectinidae.
Astropecten spinulosus is a sea star of the family Astropectinidae.
Leptasterias hexactis is a species of starfish in the family Asteriidae, commonly known as the six-rayed star. It is found in the intertidal zone of the western seaboard of the United States. It is a predator and is unusual among starfish in that it broods its eggs and young.
Luidia senegalensis, the nine-armed sea star, is a tropical species of starfish in the family Luidiidae found in the western Atlantic Ocean.
Labidiaster annulatus, the Antarctic sun starfish or wolftrap starfish is a species of starfish in the family Heliasteridae. It is found in the cold waters around Antarctica and has a large number of slender, flexible rays.
The spiny sand seastar is a species of starfish in the family Luidiidae. It is found in shallow parts of the China Sea and in the vicinity of the Korean archipelago. The tissues of this starfish have been found to contain several secondary metabolites with medicinal potential.
Astropecten armatus, the spiny sand star or Estrella de Arena, is a sea star in the family Astropectinidae. It is found on sandy or gravelly areas in the East Pacific ranging from California (USA) to Ecuador.
Asterina gibbosa, commonly known as the starlet cushion star, is a species of starfish in the family Asterinidae. It is native to the northeastern Atlantic Ocean and the Mediterranean Sea.
Astropecten duplicatus, the two-spined sea star, is a starfish in the family Astropectinidae. It is found in the eastern Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico.
Leptasterias muelleri, the northern starfish, is a species of starfish in the family Asteriidae. It is found in the Arctic Ocean and the northern Atlantic Ocean. It is a predator and scavenger and is unusual among starfish in that it broods its young.
Asterias versicolor is a species of starfish native to the southern coasts of Japan southwards to the South China Sea.
