For reasons of large body size, fast-moving predatory activities, large beak, relatively large brain, and an eye structure similar to that of humans, cephalopods rank among the most interesting of all marine invertebrates. A considerable mythology has developed around them.  The first authentic photos of a living giant squid Architeuthis were obtained only in 2005, and there are reports of even larger deep sea-inhabiting squid species.  Only 2 octopus species are commonly encountered on the northern parts of the west coast, the giant octopus1 Enteroctopus dofleini and the smaller Octopus rubescens.  Two other species2, Octopus bimaculoides and O. bimaculatus, occur only in southern California and Baja California.  Their distributions overlap but little is known of their ecological relationships.  Several species of squids inhabit, or regularly visit or wash up on, west-coast shores, including the shallow-water Rossia pacifica, the oceanic squid Doryteuthis (Loligo) opalescens, and the deep-dwelling giant squid Moroteuthis robustus. An increasingly common visitor to west-coast shores, including British Columbia and southern Alaska in summer and early autumn, is the feisty Humboldt squid Dosidicus gigas3, which likely follows incursions of warm-water northwards.  Modest fisheryies for giant octopuses Enteroctopus dofleini exists in Alaska (landings of about 200 metric tonnes annually) and Queen Charlotte Islands, British Columbia. Capture of squids Doryteuthis opalescens represents the largest fishery in California, with over 100,000 metric tonnes being harvested annually. Cosgrove & Sendall Unpubl MS from RBC Museum, Victoria, British Columbia.photograph of giant squid Moroteuthis robusta caught by fishers off the coast of Vancouver Island, British Columbia

photograph of 2 post-reproductive and dying Humboldt squids Dosidicus gigas in Baja CaliforniaNOTE1  how “giant” is the giant octopus Enteroctopus dofleini?  Specimens up to 40kg are commonly caught.  The largest individual recorded anecdotally from northern British Columbia weighed in at 270kg with a tentacle spread of 9.7m.  High 1976 Mar Fish Rev 38: 17.

NOTE2  how related are the west-coast species?  This is investigated for the 4 species mentioned here, with the addition of a deep-water Californian species Octopus californicus, by researchers at Simon Fraser University, British Columbia.  DNA-sequencing results suggest that O. bimaculoides and O. bimaculatus form their own clade, separate from a clade containing Enteroctopus dolfleini and O. californicus.  Octopus rubescens is separate from the others, but possibly more closely aligned with the southern California group.  Sosa et al. 1995 Mol Phylogenetics & Evol 4 (2): 163. 

NOTE3  up to a decade ago sightings of Humboldt squids were mostly restricted to Mexico and southern California. More recently (summer 2009), it has been seen in numbers off the coast of Vancouver Island, British Columbia and occasionally in Alaskan waters. Researchers at DFO, Nanaimo, Canada have recently attached telemetry devices to a number of specimens caught off Vancouver Island, so further information on their movements may be forthcoming

Two post-reproductive and moribund male Humboldt
squids Dosidicus gigas in Baja California being
collected as food for captive green turtles
(usually thought of as being seagrass-eaters)

Giant squid Moroteuthis robusta caught
in a trawl net off the coast of
Vancouver Island, British Columbia

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© 2010 Thomas Carefoot

To learn about west-coast OCTOPUSES & RELATIVES: select a topic from the octopus menu at the top of the page

OR: play the ANIMATION of the snail meeting the OCTOPUS

OR, if you want to see other animations: follow the snail on its ODYSSEY by CLICKING on any X-marked invertebrate on the map

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Phylum Mollusca (lit. “soft” or “shellfish” L.)

Class Cephalopoda (lit. “head foot” G.), referring to the body structure of head lying directly overtop of the muscular foot (in cephalopods, the ancestral foot evolved into arms and tentacles)

SubClass Coleoidea (lit. “sheath” G.), including octopuses and squids

Order Sepiolioidea (lit. “cuttlefish” G.), including the stubby squid Rossia pacifica

Order Teuthoidea (lit. “squid” G.), including several species of squids: Doryteuthis opalescens, the giant squid Moroteuthis (Onykia) robustus (4m in total length), the Humboldt squid, Dosidicus gigas, and the stubby squid Rossia pacifica (a small bottom-inhabiting species)

Order Octopoda (lit. “eight arms” L.), including the octopuses Enteroctopus dofleini, Octopus rubescens, O. bimaculatus and O. bimaculoides (the last 2 in California only)

NOTEOnykia robusta is smaller than Moroteuthis robusta and differs morphologically from the latter in only minor ways.  Recent molecular evidence suggests that the smaller form may be justan immature stage of the larger, and the suggestion by the authors of this latest study is that the species be known as Onykia robusta.  However, until this change is commonly adopted, this squid species will be referred to in the Odyssey by the species name used by a particular author. Wakabayashi et al. 2007 J Mar Biol Ass UK 87 (4): 959.

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