''Sclerasterias'' is a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
starfish
Starfish or sea stars are Star polygon, star-shaped echinoderms belonging to the class (biology), class Asteroidea (). Common usage frequently finds these names being also applied to brittle star, ophiuroids, which are correctly referred to ...
in the
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Asteriidae
The Asteriidae are a diverse family of Asteroidea (sea stars) in the order Forcipulatida. It is one of three families in the order Forcipulatida.
The oldest unambiguous fossils of the family date to the Late Cretaceous.
Genera
The World Regi ...
. Adult individuals have five arms but small, immature individuals have six. This led to the giving of a separate generic name to the juveniles, ''Hydrasterias'', before it was realised that only one genus was involved.
These young individuals often undergo
fissiparity. The disc splits into two parts, each bearing three arms, and new arms develop on each part to complete the complement of arms. This sometimes happens repeatedly and may be an adaptation to life in cold, deep seas where most of the species are found.
[
]
Species
The following species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
are accepted by the World Register of Marine Species:[
* '' Sclerasterias alexandri'' (Ludwig, 1905)
* '' Sclerasterias contorta'' (Perrier, 1881)
* '' Sclerasterias dubia'' (H. L. Clark, 1909)
* '' Sclerasterias eructans'' (McKnight, 2006)
* '' Sclerasterias euplecta'' (Fisher, 1906)
* '' Sclerasterias eustyla'' (Sladen, 1889)
* '' Sclerasterias guernei'' Perrier, 1891
* '' Sclerasterias heteropaes'' Fisher, 1924
* '' Sclerasterias mazophora'' (Wood-Mason & Alcock, 1891)
* '' Sclerasterias mollis'' (Hutton, 1872)
* '' Sclerasterias neglecta'' (Perrier, 1891)
* '' Sclerasterias parvulus'' (Perrier, 1891)
* '' Sclerasterias richardi'' (Perrier, 1882)
* '' Sclerasterias satsumana'' Doderlein, 1902
* '' Sclerasterias tanneri'' (Verrill, 1880)
]
References
Asteriidae
Asteroidea genera
{{Asteroidea-stub