Henricia leviuscula
Encyclopedia
Henricia leviuscula, commonly called the Pacific blood star, it is a species
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 found along the Pacific coast of North America.

Physical description

They can usually be identified by their bright orange red color, but there can also be many variations from tan to almost purple. The disk can be a mottled gray color. There can also be saddle-like marking of lilac blotches between the rays, but the rays are not mottled. They commonly have 5 rays (occasionally 4–6). The rays are slender and appear smooth due to the lack of pedicellariae
Pedicellariae
A pedicellaria is a small wrench or claw-shaped structure commonly found on Echinoderms, particularly in sea stars and sea urchins...

 and spines. The species is relatively small, the diameter is usually over 8 cm and rarely gets larger than 12 cm. As with all seastars the blood star has a madreporite
Madreporite
The madreporite is a lightcolored calcerous opening used to filter water into the water vascular system of echinoderms. It acts like a pressure-equalizing valve. It is visible as a small red or yellow button-like structure, looking like a small wart, on the aboral surface of the central disk of a...

 which can be seen below.

Reproduction and life history

Sexes are dioecious
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...

 and females are not known to brood young. This statement is in conflict with other sources that state that smaller females brood their young and larger females discharge eggs directly in the water and do not brood them. This is one reason that is leading biologists to believe this is a species complex
Species complex
A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and usually still incomplete reproductive isolation. Ring species, superspecies and cryptic species complex are example of species complex...

.
Embryonic
Embryonic
Embryonic received general acclaim from critics upon release, garnering a 81/100 critic score on Metacritic. The New Musical Express noted that "ten years after their last masterpiece, The Flaming Lips have finally produced another one," while Paste Magazine described the record as "a wonderfully...

 stages do not adhere to one another but float freely. Post-hatching larvae are ciliated and swim. Spawned eggs have been measured at 1342 μm diameter.

Behavior

In a study comparing seastar righting behavior the Henricia leviuscula twisted arms 1 and 3 toward each other, used arms 4 and 5 to support itself on the bottom of the tank, and moved arm 2 up so it was in a sitting-like position, and began to flip itself over. Overall, it had an average righting time of 15.22 minutes.

Habitat

Its habitat is the intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...

 under rocks and protected places from the low-tide line to about 400 m deep. They often have a commensal scaleworm, Arctonoe vittata.

Associations

There may be hybrids and possible distinct species that key to Henricia leviuscula. Subspecies are Henricia leviuscula annectens and Henricia leviuscula levivuscula.

Trophic strategy

They mainly feed on sponges and small bacteria.The sea star moves these tiny particles, which are captured in mucus and swept to the mouth by ciliated tracts. It may also feed by applying the stomach to the surfaces of sponges and bryozoa.

Conservation status

Not listed. Predators are humans and birds.

Related names

  • Chaetaster californicus Grube, 1856 synonym
  • Cribrella laeviuscula Sladen, 1889 synonym
  • Cribrella laeviuscula Whiteaves, 1878 synonym
  • Henricia attenuata H.L. Clark, 1901 synonym
  • Henricia inequalis Verrill, 1914 synonym
  • Henricia lunula Verrill, 1914 synonym
  • Henricia spatulifera Verrill, 1909 synonym
  • Linckia leviuscula Stimpson, 1857 synonym

External links

  • http://seanet.stanford.edu/RockyShore/Echinodermata/index.html#Henricia
  • http://enature.com/fieldguides/detail.asp?allSpecies=y&searchText=henricia%20leviuscula&curGroupID=8&lgfromWhere=&curPageNum=1
  • http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Echinodermata/Class%20Asteroidea/Henricia_leviuscula.html
  • http://bayscience.org/Animals/H/Henricia_leviuscula/
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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