Dosidicus gigas (d'Orbigny, 1835) Common name(s): Jumbo squid, Humboldt squid, Large squid
Synonyms: Ommastrephes giganteus, Dosidicus eschrichti, Dosidicus steenstrupi, Sepia nigra, Sepia tunicata
Phylum Mollusca Class Cephalopoda Subclass Coleoidea Superorder Decabrachia  Order Teuthida  Family Ommastrephidae Subfamily Ommastrephinae
	Dosidicus gigas, captured by a fisherman off Westport, WA.  Mantle length approximately 60 cm.
	(Photo by:  Kirt Onthank 2009)

How to Distinguish from Similar Species:  The opalescent or common Pacific squid Doryteuthis opalescens is more common in California shallow waters but is smaller (mantle length to 19 cm).  The North Pacific Giant Squid Moroteuthis robusta also grows very large (up to 230 cm mantle length) but the mantle contains many fine longitudinal ridges and the fins are attached along more than half the mantle length.  The tentacle clubs have 15-18 pairs of hooks in two rows along with the suckers.  It is also oceanic but occasionally washes up on our shores.  The only cephalopod this large commonly seen near Washington shores is the Pacific Giant Octopus, Enteroctopus dofleini, which has only 8 arms, does not have the elongated mantle nor mantle fins, and spends much of its time benthically.

Geographical Range:  This species is common much farther south.  Several times in the past decade, however (e.g. 2004, 2008), large numbers of individuals have appeared off the Washington Coast and as far north as Kodiak, Alaska.  Johnson and Snook give the range as Monterey, CA to San Diego.

Depth Range:  0-1200 m

Habitat:  Oceanic

Biology/Natural History:   This species is a diurnal vertical migrator from warm waters.  It is only occasionally seen along our coast.

Ramos-Castillejos et al. (2010) examined the paralarvae of this species off the west coast of Baja California.  The paralarvae are very similar in morphology to those of Sthenoteuthis oualaniensis.  However, Ramos-Castillejos et al. found several size metrics in which the paralarvae differed.  Paralarvae of Dosidicus gigas also had no intestinal photophores.

References:

General References:
  Johnson and Snook, 1955
  Norman, 2003

Scientific Articles:
Ramos-Castillejos, Jorge, César A. Salinas-Zavala, Susana Camarillo-Coop, and Luis M. Enríquez-Paredes, 2010.  Paralarvae of the jumbo squid, Dosidicus gigas.  Invertebrate Biology 129:2 pp. 172-183. 

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:
The photos below were taken by Kirt Onthank, of one of many squid which were captured by fishermen at Ocean Shores, WA in 2008.

This view shows the 8 arms and 2 tentacles characteristic of squids.  Photo by Kirt Onthank
 

This view shows the attachment along the dorsal margin of the mantle.  Photo by Kirt Onthank, 2009
 

The ventral margin of the mantle is not tightly attached to the body.  Photo by Kirt Onthank, 2009

When the mantle cavity is opened the two gills can be readily seen.  In the photo above, the opening to the mantle cavity is to the left.  Water is sucked into the rear of the mantle cavity (to the right), then blown back out across the featherlike gills which can be seen above and below.  The visceral mass is visible between the gills.  This individual washed up on a beach at Seaside, Oregon, so there is some sand in the gills.  Photo by Dave Cowles, July 2009

This closer view shows the esophagus extending to from the left to the spiral cecum and stomach on the right.  Photo by Dave Cowles, July 2009
 
 

The tentacle clubs have suckers with no teeth.  Notice the toothed ring from another (arm) sucker on the upper left.  Also notice that the proximal part of the tentacle (to the right) is not covered by suckers.  Photo by Kirt Onthank, 2009
 

The suckers are on pedicels (stalks).  Photo by Kirt Onthank 2009
 

Some of the suckers contain a ring of teeth.  The scale in the background is millimeters.  Photo by Kirt Onthank, 2009
 

The arms are angular in cross section.  Photo by Kirt Onthank, 2009

The beak appears similar to a parrot's beak.  The roots of each beak, however, extend well back into the buccal mass (the white mass of muscle around the beaks here), becoming wider, softer, and thinner as they go.  The smaller beak (on the right above) is dorsal.  Between the beaks is the radula and the salivary papilla.  The esophagus passes back through the heavy, muscular buccal mass to the stomach.  Photo by Dave Cowles, July 2009

Here is a view of the animal's otoliths.  The scale is millimeters, with centimeters numbered.  Photo by Dave Cowles, July 2009

As with all squid, Dosidicus gigas has an internal, flexible strengthening skeleton or "pen".  In this view the pen has been removed from the animal (anterior is to the right) and set on the side of the tank.  The spoon-like structure at the left fits within the posterior tip of the animal.  Photo by Dave Cowles, July 2009