| Astropecten platyacanthus | |
|---|---|
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| Astropecten platyacanthus on sea bottom | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Asteroidea |
| Order: | Paxillosida |
| Family: | Astropectinidae |
| Genus: | Astropecten |
| Species: | A. platyacanthus |
| Binomial name | |
| Astropecten platyacanthus (Philippi, 1837) | |
Astropecten platyacanthus is a sea star of the family Astropectinidae.
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 starfishes go out to hunt mainly bivalve molluscs, which are their favourite preys. This species lives only in the Mediterranean Sea and it lives on all mobile seabed at depths between 1 and 60 m, but it is more frequently in seabed of mixed coarse sand and mud at 1–4 m depth. This species is active and easy to find during the night but also during the day, especially in early morning and late afternoon.
It has narrow and high superomarginal plates, laterally covered with scales and small spines (on vertical face). Every superomarginal plates is equipped with one strong spine, usually sharp but irregularly shaped, slightly flattened laterally, often yellow or orange but rarely off white. Sometimes, especially in young specimen, only superomarginal plates between the arms are equipped with one strong spine while others are not (in some rare specimens all the superomarginal plates are totally devoid of spines). In populations of certain areas of the Mediterranean (for example, the South of Corsica) this feature is very frequent. The superomarginal spines are (more or less) far from the inside edge of plates and they leave on top, on the base of them, a small bare area that it is white if there is a strong spine in the plate (usually in the plates near the disc) or blue-violet if the plate has very small spine or no spine (usually towards the tip of arms). The maximum number of superomarginal plates, observed on each arm, is 48; normally the number is between 29 and 43, depending on the size of the starfish. The inferomarginal spines are long, flat and quite pointed. It is an Astropecten with very variables features and it can have wide or narrow arms. The aboral side has very variables colours and it can be more or less dark brown, olive green, pink-brown, bluish-grey. The oral side usually is yellow-brown. Normally it reaches a diameter of 9–12 cm and exceptionally it can measure up to 18 cm. It is the Mediterranean Astropecten hardest to identify both for the variability of features of the species, both for the resemblance to some other species.
It is distinguished from Astropecten bispinosus mainly for the superomarginal spines far from the inside edge of plates and they leave on top, on the base of them, a small bare area. Another important Astropecten platyacanthus’s feature is that the superomarginal plates are laterally, on vertical face, covered with scales and small spines rather than nude. Moreover, it is different because it has smaller, irregularly shaped, laterally flattened (rather than clean conical spine) superomarginal spines and because it has average less superomarginal plates on each arm. In addition, on average Astropecten platyacanthus has a central disc larger, a darker oral side and a small red point in the point of arms have.
A = Astropecten platyacanthus is distinguished from Astropecten bispinosus for the superomarginal spines far from the inside edge of plates. They leave on top, on the base of them, a small bare area. B = Astropecten platyacanthus is a bit different from Astropecten bispinosus for the superomarginal spines smaller, irregularly shaped, laterally flattened (rather than clean conical spine). C = Astropecten platyacanthus is distinguished from Astropecten bispinosus for the vertical face of superomarginal plates, that are laterally covered with scales and small spines rather than nude D = Astropecten platyacanthus is a bit different from Astropecten bispinosus for the inferomarginal spines, sometime less pointed.
It is distinguished from Astropecten spinulosus by very different superomarginal plates: highest, defined and equipped with very big and strong superomarginal spines and they have very different plates. Secondly, the general appearance of the starfish and the colour are usually different: Astropecten spinulosus is always slenderer and dark brown with superomarginal spines brown and inferomarginal spines blue-purple. Astropecten platyacanthus reaches or exceeds 10 cm in diameter, while Astropecten spinulosus reaches at maximum just under 10 cm in diameter.
Young specimens of Astropecten platyacanthus sometimes can be confused with Astropecten jonstoni for the appearance and the colour, but it is always easy to distinguish them by very different superomarginal plates and superomarginal spines.
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 grey triggerfish, or gray triggerfish, is a species of ray-finned fish in the triggerfish family. The species is native to shallow parts of the western Atlantic from Nova Scotia to Argentina and also the eastern Atlantic, the Mediterranean Sea and off Angola on the west coast of Africa.
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.
Culcita novaeguineae is a species of starfish. It has short arms and an inflated appearance and resembles a pentagonal pincushion. It is variable in colour and can be found in tropical warm waters in the Indo-Pacific.
Astropecten irregularis is a sea star of the family Astropectinidae. Common names include Sand sea star.
Astropecten bispinosus is a sea star of the family Astropectinidae from the Mediterranean Sea.
Astropecten jonstoni is a sea star of the family Astropectinidae.
Astropecten spinulosus is a sea star of the family Astropectinidae.
Luidia clathrata is a tropical species of starfish in the family Luidiidae. It is variously known as the slender-armed starfish, the gray sea star, or the lined sea star. It is found in the western Atlantic Ocean.
Luidia senegalensis, the nine-armed sea star, is a tropical species of starfish in the family Luidiidae found in the western Atlantic Ocean.
Luidia foliolata, the sand star, is a species of starfish in the family Luidiidae found in the northeastern Pacific Ocean on sandy and muddy seabeds at depths to about 600 m (2,000 ft).
Echinaster spinulosus, the small spine sea star, is a species of sea star found in shallow parts of the western Atlantic Ocean, the Caribbean Sea and Gulf of Mexico.
Ophiura albida is a species of brittle star in the order Ophiurida. It is typically found on the seabed in the north eastern Atlantic Ocean and in the Mediterranean Sea and is sometimes known as the serpent's table brittle star.
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.
Asterina pancerii, commonly known as the seagrass asterina, is a species of starfish in the family Asterinidae. It is native to shallow parts of the Mediterranean Sea where it is usually found in seagrass meadows.
