''Sclerasterias'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
starfish
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 ...
in the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Asteriidae. 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
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
are accepted by the World Register of Marine Species:[
* '' Sclerasterias alexandri'' (Ludwig, 1905)
* '' Sclerasterias contorta'' (Perrier, 1881)
* '']Sclerasterias dubia
''Sclerasterias'' is a genus of starfish in the family Asteriidae. 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 ...
'' (H. L. Clark, 1909)
* '' Sclerasterias eructans'' (McKnight, 2006)
* '' Sclerasterias euplecta'' (Fisher, 1906)
* '' Sclerasterias eustyla'' (Sladen, 1889)
* '' Sclerasterias guernei'' Perrier, 1891
* ''Sclerasterias heteropaes
''Sclerasterias'' is a genus of starfish in the family Asteriidae. 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 ...
'' Fisher, 1924
* ''Sclerasterias mazophora
''Sclerasterias'' is a genus of starfish in the family Asteriidae. 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 ...
'' (Wood-Mason & Alcock, 1891)
* ''Sclerasterias mollis
''Sclerasterias'' is a genus of starfish in the family Asteriidae. 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 ...
'' (Hutton, 1872)
* ''Sclerasterias neglecta
''Sclerasterias'' is a genus of starfish in the family Asteriidae. 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 ...
'' (Perrier, 1891)
* ''Sclerasterias parvulus
''Sclerasterias'' is a genus of starfish in the family Asteriidae. 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 ...
'' (Perrier, 1891)
* ''Sclerasterias richardi
''Sclerasterias'' is a genus of starfish in the family Asteriidae. 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 ...
'' (Perrier, 1882)
* ''Sclerasterias satsumana
''Sclerasterias'' is a genus of starfish in the family Asteriidae. 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 ...
'' Doderlein, 1902
* ''Sclerasterias tanneri
''Sclerasterias'' is a genus of starfish in the family Asteriidae. 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 ...
'' (Verrill, 1880)
References
Asteriidae
{{Asteroidea-stub