Parastichopus californicus (Stimpson, 1857)

California Sea Cucumber
Synonyms: 
Stichopus californicus
Phylum Echinodermata
 Class Holothuroidea
   Order Aspidochirotida
     Family Stichopodidae
Found in Rosario Bay, WA.  Side view.  Animal is approx. 20cm in length.
Photo by: Kelly Williams, June 2002
Description:  Large sea cucumber ranging from 25 to 40cm in body length.  Dorsal and lateral surfaces dark red, brown, or yellow.  The body surface bears large, stiff, conical papillae or pseudospines.  Papillae are usually paler in color than body surface and tipped with red.  Tube feet are densely arranged on the ventral side and only three pairs of rows are distinct.  The mouth is directed ventrally at the anterior end and is surrounded by tentacles.

How to Distinguish from Similar Species:Parastichopus parvimensis, which lives from Monterey Bay south, is very similar in form and can grow to nearly as large, but the body is chestnut brown dorsally and much paler below; plus the tips of its papillae are tipped with black instead of red.

Geographical Range:  Gulf of Alaska to Baja California

Depth Range:  Low intertidal zone to 90 m deep

Habitat:  Exposed and sheltered areas protected from strong wave action.  Subtidal species are found primarily on gravel and shell debris

Biology/Natural History:  P. californicus is the largest sea cucumber species along the Pacific Northwest coast.  The species feeds on organic detritus and small organisms, which it ingests with bottom sediments.  The primary predators of P. californicus are the sea stars Pycnopodia helianthoides and Solaster endeca, but the species is also occasionally eaten by sea otters and man.  Unlike many tropical sea cucumbers, P. californicus does not store substances toxic to predators.  The hindgut bears a pair of highly branched diverticula, which project into the coelomic cavity of the body and serve as “water lungs”.  Oxygenated water is pumped into these respiratory trees in several successive inhalations and then expelled in one powerful exhalation.  Breeding occurs in the summer.  Development is indirect.  The sperm have spherical heads and an unusually low DNA content.  The fertilized eggs develop into auricularia larvae which metamorphose into doliolaria larva which settle.  The pelagic phase lasts from 7 to 13 weeks in the laboratory.  Populations of P. californicus in the Puget Sound eviscerate during October and November and then regenerate new sets of organs.  Evisceration may also occur if the animals are kept in warm or stale water.  The scale worm Arctonoe pulchra may occur as a commensal on P. californicus.


 
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References:
Dichotomous Keys:
Kozloff, 1987

General References:
Morris, Abbott, and Haderlie, 1992.
Kozloff, 1993.
O'Clair and O'Clair, 1998

Scientific Articles:
 
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

Woodby, D., S. Smiley, and R. Larson, 2000.  Depth and habitat distribution of Parastichopus californicus near Sitka, Alaska.  Alaska Fishery Research Bulletin 7: 22-32


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


Another photo of Parastichopus californicus.  This species can become short, round, and turgid or long, limp, and flaccid.  Photo by Dave Cowles, July 1997

On June 22, 2005 divers from the station gathered 5 P. californicus for an experiment.  All five were placed into the same running seawater tank, measuring 170 x 48 x 120 cm.  Within a few hours (about sundown) four of the five cucumbers began releasing gametes into the water.  All gametes released were in a thin, wispy white stream which looked like sperm.  They continued releasing gametes until the tank, though it was being gently flushed with seawater, was cloudy.  Gamete release continued for at least half an hour.  The day before (June 21) had been the full moon.  Below I have a still photo, plus a link to a digital movie of gamete release by the cucumbers.


Gametes being released by Parastichopus californicus. Photo by Dave Cowles June 22, 2005.

Here is a link to a digital .MPG movie of Parastichopus releasing gametes on June 22, 2005.


This individual is feeding on the sediment near Rosario.  Photo by Jim Nestler, July 2005
 

Abstract from Kari McCloskey MS thesis, Department of Biology, Walla Walla College, May 2006:

Diel and Seasonal Cycles of Movement, Metabolism, and Nutrient Excretion by the Temperate Holothurian Parastichopus californicus

Sea cucumbers (Phylum Echinodermata, Class Holothuroidea) influence ocean communities by affecting physical and chemical characteristics of water and sediment through their deposit feeding and excretion activities.  Several tropical species of sea cucumbers exhibit daily cycles of behavior and physiological processes, though research on this phenomena in temperate waters is limited.  Seasonal cycles of behavior and physiological processes have also been observed to occur among temperate and tropical species.  Daily and seasonal movement rates, metabolism, and nutrient excretion were measured for the temperate sea cucumber Parastichopus californicus.  Daily differences in phosphate excretion were noted for P. californicus during the summer, with significantly greater concentrations recorded at night than during the day.  No day vs. night differences were observed for movement, metabolism, or ammonium excretion by P. californicus in either summer or winter.  Movement rate and the concentration of excreted phosphate were significantly lower during winter than in the summer.  Metabolic rate however, was significantly greater during the winter compared to the summer.  Animal size varied seasonally, with mass and volume during the winter being significantly less than in the summer.  These data suggest that some behavioral and physiological process of P. californicus may occur over daily and seasonal cycles, while others do not.
 


The moplike tentacles are visible in this feeding individual.
Underwater photo by Kirt Onthank, July 2007
 
 
 


Authors and Editors of Page:
Kelly Williams (2002):  Created original page
Edited by Hans Helmstetler 12-2002; Dave Cowles 2005