Parastichopus californicus (Stimpson, 1857)
Common name: California Sea Cucumber, giant sea cucumber
Stichopus californicus, Holothuria californica
|Found in Rosario Bay, WA. Side view. Animal is approx. 20cm in length.|
|Photo by: Kelly Williams, June 2002|
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. Parastichopus leucothele is colored similarly but lives at deeper depths (24-285 m) and is colored bright orange with rusty brown patches and small white papillae.
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 (photo) 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.
Recently this species has been discovered to be able to take
up nutrients via the respiratory tree in the anus. Brothers
et al. (2011) found that labeled stable isotopes from the seawater made
their way into the cucumber through the anus and respiratory tree,
especially in late winter/early spring when the animal was regenerating
its gut. Jaeckle and Strathmann (2013) found that
radiocarbon-labelled unicellular algae and iron-containing
macromolecules could also be incorporated into animal tissues via the
|Main Page||Alphabetic Index||Systematic Index||Glossary|
Lamb and Hanby, 2005
Morris, Abbott, and Haderlie, 1992.
O'Clair and O'Clair, 1998
Brothers, C.J., J. R. Nestler, and R.W. Lee, 2011. Visceral regeneration by the uptake of dissolved organic material in the sea cucumber Parastichopus californicus. Abstract, 6th North American Echinoderm Conference, Anacortes, WA.
Jaeckle, William B. and Richard R. Strathmann, 2012. The anus as a second mouth: anal suspension feeding by an oral deposit-feeding sea cucumber. Invertebrate Biology 132: pp 62-68
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
D., S. Smiley, and R. Larson, 2000. Depth and
of Parastichopus californicus near Sitka,
Alaska. Alaska Fishery
Research Bulletin 7: 22-32
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:
The moplike tentacles are visible in this feeding individual.
Underwater photo by Kirt Onthank, July 2007
This individual eviscerated its gut and respiratory tree after being held a few minutes July 6, 2010. Photo by Dave Cowles