Henricia leviuscula (Stimpson, 1857) 

Common name(s): Blood star, Pacific blood star
Synonyms:  Linckia leviuscula
Phylum Echinodermata
 Class Asteroidea
  Order Spinulosida
   Suborder Leptognathina
    Family Echinasteridae
Henricia leviuscula, collected from 100-150 m depth in San Juan Channel
(Photo by: Dave Cowles,  July 2005)
Description:  With 5 (occasionally 4 or 6) rays and a central disk less than 1/5 of total width.  The aboral surface is slightly gritty due to the ridgelike network of tiny ossicles separating small depressions between.  The ridges are composed of clusters of small spines (paxillae) easily visible under magnification (picture), and are wider than the depressions between.  No pedicellariae.  Three rows of enlarged marginal plates (not clearly visible except under magnification) line the edges of the ambulacral grooves (picture).  Ambulacral grooves are narrow (picture).  Base of rays are not so thickened that they are separated from one another by a crease which extends onto the disk.  Color cream or bright orange; not mottled.  Genital pores (between rays) slightly aboral to the margin of the disk.  Rarely over 12 cm diameter.

How to Distinguish from Similar Species: This species is variable and is likely a species complex.  H. sanguinolenta has no prominent marginal plates and the rays are thickened at the base, forming creases between them.  Henricia sp. is genital pores slightly oral to the margin of the disk and is a mottled color.

Geographical Range: Aleutian Islands, AK to Baja California, Mexico; Japan

Depth Range: Low intertidal to 671 m

Habitat: Common in the rocky intertidal and subtidally in rocky and shelly hash areas.

Biology/Natural History: Feeds mainly on sponges, or on particulates which stick to mucus on the body surface and are passed to the mouth.  Often has a commensal scaleworm, Arctonoe vittata.  Small females may brood their young in winter (or the brooders may be a separate species).  Has ocelli at the tips of the rays.

Henricia leviuscula is fairly stiff with only small papulae and tube feet.  It seems to rely much more on seawater uptake through the madreporite than does Leptasterias hexactis, another intertidal species of similar size (Ferguson, 1994).


 
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References:

Dichotomous Keys:
  Kozloff 1987, 1996
  Smith and Carlton, 1975
 

General References:
  Brusca and Brusca, 1978
  Harbo, 1999
  Kozloff, 1993
  McConnaughey and McConnaughey, 1985
  Niesen, 1994
  Niesen, 1997
  O'Clair and O'Clair, 1998
  Ricketts et al., 1993
  Sept, 1999
  Snyderman, 1988

Scientific Articles:

Ferguson, John C., 1994.  Madreporite inflow of seawater to maintain body fluids in five species of starfish.  pp. 285-289 in Bruno David, Alain Guille, Jean-Pierre Feral, and Michel Roux (eds).  Echinoderms through time.  Balkema, Rotterdam.

McEdward, Larry R. and Benjamin G. Miner, 2006.  Estimation and interpretation of egg provisioning in marine invertebrates.  Integrative and Comparative Biology 46:3 pp 224-232
 


General Notes and Observations:  Locations, abundances, unusual behaviors:



This species is found in many sizes and colors, and may be a species complex.  Photo by Dave Cowles, July 2005

The ossicles on the aboral side form a branching network of small papillate bumps.



The ossicles along the margin of the ambulacral grooves are larger, usually lighter, and form 3 rows.



The ambulacral groove is narrow.  Here the enlarged marginal ossicles can also be seen.  Photo by Dave Cowles, July 2005



A beige form is especially common in deep water.  Collected at 100-150 m in San Juan Channel.  Photo by Dave Cowles, July 2005

This distorted individual was trawled from 100-150 m depth in the San Juan Channel.  Photos by Dave Cowles, July 2005



A saddle-like marking of lilac blotches between the rays is a common color variant.  Collected at 100-150 m depth,San Juan Channel.  Photo by Dave Cowles, July 2005


This individual, photographed underwater by Kirt Onthank near Northwest island in February 2006, has even more pronounced lilac patches over the base of the rays and the central disk.
The nudibranch is Cadlina luteomarginata.

In summer 2005 three students, Shannon Greenlaw, Jill Interlichia, and Lyndi Hetterle did a student research project titled "Nocturnal vs diurnal levels of activity in Henricia leviuscula.  They placed 15 blood stars in an outdoor tank and placed a video time-lapse camera overhead to record their movement.  They found that the seastars moved significantly more during the day than at night.  They were not able to determine whether this was a natural level of movement or whether the seastars were searching for shelter from the sunlight, though a number of stars continued substantial levels of movement even after entering the shade.  The figure below of mean distance moved as a function of time of day summarizes their data.  Daylight hours are from approximately 6:00 to 21:30.


Authors and Editors of Page:
Dave Cowles (2005):  Created original page