Astropecten

Astropecten
Astropecten platyacanthus
Scientific classification
Kingdom: Animalia
Phylum: Echinodermata
Subphylum: Eleutherozoa
Class: Asteroidea
Order: Paxillosida
Family: Astropectinidae
Genus: Astropecten
Gray, 1840
Species

See text.

Astropecten is a genus of sea star of the family Astropectinidae.

Contents

Species

Mediterranean's Species

Anatomy

These sea stars are similar one to each other and it can be difficult to determine with certainty the species only from a photograph. To have a certain determination, in some cases, animals should be analyzed in the laboratory or using genetic testing, but often it isn’t possible. In order to determine the species, with a reasonable margin of error, it’s necessary to observe the appearance of the animal, in particular, based on some typical features described by principal authors that have analyzed over the years a large number of specimens in the laboratory. The main elements, to determine the various species from photo, are: the appearance of the dorsal marginal plates and spines, the size, the shape of disc and arms. For a good identification by sea photo is important to take a complete picture of all the subject, a picture of the detail of the marginal plates and to measure as precisely as possible the diameter of the sea star. All this can be done without touching, turn in, or disturb the animal. Starfishes have two sides: an upper side called “aboral side” (which is normally visible), and a bottom side called “oral side” (which resting on seabed)

1- papulas: they are soft and retractable appendages with respiratory functions 2- paxilla 3- superomarginal spines 4- superomarginal plates 5- scales and small spines covering the vertical face of superomarginal plates 6- ambulacral plates 7- adambulacral plates 8- inferomarginal plates 9- inferomarginal spines 10- pedicellaria: special pedicels with prehensile termination necessary to grab bodies and detritus 11- external adambulacral spines 12- median adambulacral spines 13- internal adambulacral spines 14- ambulacral pedicellaria

References

External links