Stephanasterias albula
Encyclopedia
Stephanasterias albula is a species
of starfish in the family
Asteriidae
. It is the only species in its genus
, Stephanasterias, which was described by Verrill in 1871. It has a circumboreal
distribution and is found in the north west Atlantic Ocean, the north east Pacific Ocean, the Barents Sea and European waters. It usually has eight arms and is white with a rough upper surface. It has been trawled from depths of 267 metres.
Reproduction is by fission
. A furrow develops across the disc and the animal divides into two halves. New arms develop on the injured surfaces. A lack of any juvenile or young specimens found leads to the view that there is no larval recruitment and that this species only reproduces by fissiparity.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of starfish in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Asteriidae
Asteriidae
Asteriidae is a family of Asteroidea in the order Forcipulatida.-Genera:Genera within the family Asteriidae include:* Ampheraster Fisher, 1923 * Anteliaster Fisher, 1923 * Aphanasterias * Asterias Linnaeus, 1758...
. It is the only species in its genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, Stephanasterias, which was described by Verrill in 1871. It has a circumboreal
Circumboreal Region
The Circumboreal Region is a floristic region within the Holarctic Kingdom in Eurasia and North America, as delineated by such geobotanists as Josias Braun-Blanquet and Armen Takhtajan....
distribution and is found in the north west Atlantic Ocean, the north east Pacific Ocean, the Barents Sea and European waters. It usually has eight arms and is white with a rough upper surface. It has been trawled from depths of 267 metres.
Biology
S. albula is an omnivore, predator and scavenger.Reproduction is by fission
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
. A furrow develops across the disc and the animal divides into two halves. New arms develop on the injured surfaces. A lack of any juvenile or young specimens found leads to the view that there is no larval recruitment and that this species only reproduces by fissiparity.