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 Dosidicus gigas
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)
Description:   As with other squid, this pelagic cephalopod has 8 arms plus two tentacles (the arms taper to the end, while the tentacles have a wider, flattened "club" region near the tip).  The suckers are on pedicels (stalked) (photo), and the suckers on the tentacles may contain hooks (photo).  The body is elongated and has fins.  Has an internal, flexible skeletal gladius ("pen").  As a member of Order Teuthoidea, they eye is covered with a transparent membrane, the tentacle clubs (expanded ends of the tentacles) are narrow, and the tentacles do not retract into pockets.  The arms are long and angular in cross section (photo); the ventral pair of arms are longer and broader than the others.  The left ventral arm of the male is a hectocotyl.  The mantle is elongated (much longer than wide).  This species is very large in size (mantle length up to 150 cm), and the mantle is smooth.  The fins attached to the mantle are triangular, less than half as long as the mantle, and are attached along their full length.  The tentacle clubs have only suckers (no hooks) (photo).  The suckers are found on less than half the total length of the two longest arms or the tentacles.

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:

Dichotomous Keys:
  Carlton, 2007
  Jorgensen, 2009

General References:
  Johnson and Snook, 1955

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.


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


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


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


Gills
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


Spiral cecum and stomach
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
 
 


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


Teeth on suckers
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


Beak

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


Otoliths

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

Pen

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



Authors and Editors of Page:
Dave Cowles (2008):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)