How to Distinguish from Similar Species: Looks almost identical to E. quinquesemita. The subtle differences are that E. quinquesemita has wider and less abundant tube feet with a narrower space between the ambulacra. Its body wall is also thicker, with more support from calcareous elements. E. quinquesemita has the large, oval ossicles and also smaller, basket-shaped ossicles in the skin which E. pseudoquenquesemita lacks. E. quinquesemita is more abundant intertidally in British Columbia (and south?) while E. pseudoquinquesemita is more abundant intertidally in Alaska and is mostly subtidal in our area.
"Quinquesemita" meand five foot paths, referring to the five distinct rows of tube feet.
Geographical Range: Aleutian Islands to Puget Sound
Depth Range: Intertidal to 200 m
Habitat: Under and between rocks and in crevices. Often found in areas of strong current.
History: This species often
holds algae, shell, or rock fragments. Predators include the sea stars
helianthoides, and Dermasterias
imbricata, and juvenile Eupentacta
are a staple food for
hexactis. In my experience adults rarely
expose their tentacles
during daylight hours or after capture. Typically have bits
and other materials attached here and there to the tube
feet. Spawning occurs in the spring (March to
is indirect. Eggs, embryos, and larvae are greenish in
The body wall is poisonous to at least some fish. This
(see below). Thyonicola americana is a
shell-less snail that
parasitizes the gut.
Kozloff, 1987, 1996
Deichmann, E., 1937. The Templeton Crocker expedition. IX. Holothurians from the Gulf of California, the west coast of Lower California and Clarion Island. Zoologica (New York) 22 pp 161-176
Tikasingh, E.S., 1960. Endoparasitic gastropods of some Puget Sound holothurians. Journal of Parasitology (Supplement) 46 p 13
Takasingh, E.S., 1961. A new genus and two new species
gastropods from Puget Sound, Washington. Journal of Parasitology 47 pp
General Notes and Observations: Locations, abundances, unusual behaviors, etc.:
The sister species E. quinquesemita is known to eviscerate, but little is recorded for this species. Shortly after collection the individual above began to eviscerate, starting at the anterior end. Within a few minutes it had eviscerated its oral tentacles, the anterior calcareous ring, and its entire gut (see below). Eerily, even after evisceration the oral tentacles continued to make feeding-like motions for about an hour, as seen in this video.
Authors and Editors of Page:
Kelly Williams (2002): Created original page
Edited by Hans Helmstetler 12-2002; Dave Cowles 2013