The Asterinidae are a large
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 ...
of
sea star
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 ...
s in the
order Valvatida
The Valvatida are an order of starfish in the class Asteroidea, which contains 695 species in 172 genera in 17 families.
Description
The order encompasses both tiny species, which are only a few millimetres in diameter, like those in the gen ...
.
Description and characteristics
These are generally small sea stars, flattened dorsally and bearing very short arms, often giving a pentagonal shape in the body ;example: ''Asterians rubens'' (except in some species possessing more than five arms). The periphery of the body is thin and formed by indistinct, tiny marginal plates. They are characterized by their aboral face formed by plates shaped like crescents, sometimes giving a "knitted" appearance to the skin.
The abyssal species can be bigger, like those of the genus ''
Anseropoda'', which can exceed 45 cm in diameter.
Biology
Most of the species are small and relatively cryptic: they are often found hidden under rocks or in crevices, for example. Several species have access to a fissiparous
asexual reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the f ...
, multiplying their reproductive potential. For that reason, some species of the genera ''
Meridiastra'' and ''
Aquilonastra'' can sometimes appear spontaneously in aquariums, where they can proliferate from just one larva imported inadvertently. Some species can brood their young (which thus do not pass through a planctonic larval stage), such as ''
Asterina pancerii''.
Most of the species feed on food fragments and algal or bacterial mat covering the substratum, evaginating their stomach on their food (a frequent feeding mode in sea stars). However, some species like ''
Stegnaster inflatus'' takes advantage of their webbed shape to form a "trap" by heightening on the tip of their arms, and suddenly falling on a prey which would have believed to find shelter there.
They can be found in almost all the seas of the world, from the abysses to the surface and from the poles to the tropics.
Genera
This family comprises about 21
genera
Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...
and 116
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), ...
according to O'Loughlin & Waters (2004),
whereas the World Asteroidea Database states that it includes 150 species in 25 genera.
[
Genera included in the family according to the World Asteroidea Database:][
* '' Ailsastra'' O'Loughlin & Rowe, 2005
* '' Allopatiria'' Verrill, 1913
* '' Anseropoda'' Nardo, 1834
* '' Aquilonastra'' O'Loughlin in O'Loughlin & Waters, 2004
* '' Asterina'' Nardo, 1834
* '' Asterinides'' Verrill, 1913
* '' Asterinopsis'' Verrill, 1913
* '' Callopatiria'' Verrill, 1913
* '' Cryptasterina'' Dartnall & al. 2003
* '' Disasterina'' Perrier, 1875
* '' Indianastra'' O'Loughlin in O'Loughlin & Waters, 2004
* '' Kampylaster'' Koehler, 1920
* '' Manasterina'' H.L. Clark, 1938
* '' Meridiastra'' O'Loughlin, 2002
* '' Nepanthia'' Gray, 1840
* '' Paranepanthia'' Fisher, 1917
* '' Parvulastra'' O'Loughlin in O'Loughlin & Waters, 2004
* '' Patiria'' Gray, 1840
* '' Patiriella'' Verrill, 1913
* '' Pseudasterina'' Aziz & Jangoux, 1985
* '' Pseudonepanthia'' A.H. Clark, 1916
* '' Pseudopatiria'' O'Loughlin in O'Loughlin & Waters, 2004
* '' Stegnaster'' Sladen, 1889
* '' Tegulaster'' Livingstone, 1933
* '' Tremaster'' Verrill, 1880
* '' Ctenaster'' L. Agassiz, 1836
* '' Desmopatiria'' Verrill, 1913
Image:Ailsastra eleaumei.jpg, '' Ailsastra eleaumei'' ( MNHN)
Image:Allopatiria ocellifera.jpg, '' Allopatiria ocellifera'' ( MNHN)
Image:Anseropoda placenta.jpg, '' Anseropoda placenta''
Image:Aquilonastra conandae Réunion.png, '' Aquilonastra conandae''
Image:Asterina gibbosa Pennant, 1777.jpg, '' Asterina gibbosa''
Image:Asterinides pilosa.jpg, '' Asterinides pilosa'' ( MNHN)
Image:Red starfish at Rocky Bay PB022164.JPG, '' Callopatiria granifera''
Image:Cryptic sea star (Cryptasterina sp.).jpg, '' Cryptasterina sp.''
Image:Disasterina abnormalis (MNHN-IE-2017-1490).jpg, '' Disasterina abnormalis''
Image:Indianastra sarasini - Plate 12 (Clark, 1938) (cropped).jpg, '' Indianastra sarasini''
Image:Kampylaster incurvatus (USNM 1116307) 002.jpeg, '' Kampylaster incurvatus''
Image:Meridiastra calcar.jpg, '' Meridiastra calcar''
Image:Pale scaly sea star (Nepanthia maculata).jpg, '' Nepanthia maculata''
Image:Paranepanthia.jpg, '' Paranepanthia sp.''
Image:Parvulastra exigua 2.jpg, '' Parvulastra exigua''
Image:Asterina pectinifera ja01.jpg, '' Patiria pectinifera''
Image:Small barnacles and subtidal cushion star at Lorry Bay PB011900.JPG, '' Patiriella dyscrita''
Image:Pseudonepanthia troughtoni PC269945.JPG, '' Pseudonepanthia troughtoni''
Image:Ambush starfish (Stegnaster inflatus).jpg, '' Stegnaster inflatus''
Image:Tremaster mirabilis.jpg, '' Tremaster mirabilis''
]
References
Bibliography
*
*
External links
*
*
*
{{Taxonbar, from=Q2719603
Echinoderm families
Taxa named by John Edward Gray