How to Distinguish from Similar Species: No similar species.
Geographical Range: This species ranges is along the north Pacific rim from Japan to southern California.
Depth Range: This species is benthic in coastal waters, subtidal (16-370 m) but on rare occasions at night found swimming at the shore in the intertidal zone.
Habitat: This species is fairly common on bottoms of sand or muddy sand.
History: These small
sepiolids crawl on their arms or swim, and dig shalow depressions in
sea floor, in which they rest wit htheir arms rolled under their
They inhabit shrimp beds; over 80% of their diet consists of shrimp,
crabs, mysids, small fishes, and cephalopods are also eaten.
occurs in the summer and fall in deep water. Each egg (4-5 mm
diameter) is contained in a large (8 mm by 15 mm) capsule.
are attached singly or in small groups to seaweeds or other objects on
Hochberg, F.G., 1998. Class Cephalopoda: Taxonomic Atlas of the Benthic Fauna of the Santa Maria Basin and the Western Santa Barbara Channel. Volume 8 part 1: The Aplacophora, Polyplacophora, Scaphopoda, Bivalvia and Cephalopoda, pp. 1-250. P.V. Scott and J.A. Blake, Editors. Santa Barbara Museum of Natural History, Santa Barbara, CA, USA
General Notes and Observations: Locations, abundances, unusual behaviors, etc.:
Nine species of dicyemid mesozoans have been recorded from the kidneys and branchial hearts of R. pacifica. Of these, only two are known to occur off the west coast: Dicyemennea brevicephaloides and D. parva.
This individual, with body length about 7 cm long not
was also collected by otter trawl in the San Juan
Photo August 2011 by Dave Cowles
Authors and Editors of Page:
Anna Dyer (2002): Created original page
Edited by Hans Helmstetler 12-2002, Dave Cowles 2005