''Henricia leviuscula'', commonly called the Pacific blood star, it is a

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 ...

of sea star found along the Pacific coast of North America.

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 a 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 smooth and appear smooth due to the lack of

pedicellariae A pedicellaria (plural: pedicellariae) is a small wrench- or claw-shaped appendage with movable jaws, called valves, commonly found on echinoderms (phylum Echinodermata), particularly in sea stars (class Asteroidea) and sea urchins (class Echinoi ...

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 The madreporite is a light colored calcareous 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 smal ...

which can be seen in the image below.

Reproduction and life history

Sexes are

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

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 In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

Embryonic Embryonic may refer to: *Of or relating to an embryo * ''Embryonic'' (album), a 2009 studio album by the Flaming Lips *''Embryonics ''Embryonics'' is a double-CD compilation of tracks by the Australian progressive metal band, Alchemist. It w ...

stages do not adhere to one another but float freely. Post-hatching larvae are

ciliated The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projecti ...

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.

Distribution

Its range is from Alaska to Baja California.

Habitat

Its habitat is the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

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

Arctonoe vittata ''Arctonoe vittata'' is a species of scaled polychaete worms commonly known as a "scale worm". This species often lives as a commensal of another marine animal. Description At least thirty pairs of elytra, scale-like modifications to the dorsal ...

''.

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

Common names

Pacific blood star, Blood star, Blood star fish.Henricia leviuscula (Stimpson, 1857). (2010, May 07). Retrieved May 07, 2010, from Encyclopedia of Life: http://www.eol.org/pages/598509

Notes

References

*Lester B. Pearson College. (2001, December 1). Henricia leviuscula. Retrieved May 8, 2010, from Racerocks.com: http://www.racerocks.com/racerock/eco/taxalab/taniam.htm *Catalogue of Life. (2008). Retrieved May 8, 2010, from Species 2000: http://www.catalogueoflife.org/annual-checklist/2008/browse_taxa.php?selected_taxon=991569 *Cowles, D. (2005). Henricia leviuscula. Retrieved May 8, 2010, from Key to Invertebrates Found At or Near Rosario Beach: http://www.google.com/imgres? *Douglas J. Eernise, M. F. (2010). Henricia pumila sp. nov.: A brooding seastar (Asteroidea) from the coastal. Retrieved May 11, 2010, from http://www.mapress.com/zootaxa/2010/f/zt02329p036.pdf *imgurl=http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Echinodermata/Class%2520Asteroidea/Henricia_leviuscula4sDLC2005.jpg&imgrefurl=http://www.wallawalla.edu/academics/departments/biology/rosario/inver *Henricia leviuscula (Stimpson, 1857). (2010, May 7). Retrieved May 7, 2010, from Encyclopedia of Life: http://www.eol.org/pages/598509 *Kozloff, E. N. (1996). Marine Invertebrates of the Pacific Northwest. Seattle : University of Washington Press. *Kozloff, E. N. (1993). Seashore Life of the Northern Pacific Coast. Seattle: University of Washington Press. *Meinkoth, N. A. (1981). National Audubon Society Field Guide to North America Seashore Creatures. New York: Chanticleer Press, Inc. *Sarah Pearson, S. P. (2008, July 11). Righting Behavior of Sea Stars. Retrieved May 2010, 8, from https://scholarsbank.uoregon.edu/xmlui/bitstream/handle/1794/7841/Pearson-Pedemonte.pdf?sequence=1

External links

* https://web.archive.org/web/20100722122347/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 * https://web.archive.org/web/20100602122044/http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Echinodermata/Class%20Asteroidea/Henricia_leviuscula.html * https://web.archive.org/web/20110725043229/http://bayscience.org/Animals/H/Henricia_leviuscula/ * {{Taxonbar, from=Q2187343 Echinasteridae Starfish described in 1857