Under Construction

Opisthoteuthis Verrill 1883

Flapjack devilfishes

Roger Villanueva, Richard E. Young, and Michael Vecchione
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
The following 19 nominal species are included in the genus.
taxon links [up-->]Opisthoteuthis bruuni [up-->]Opisthoteuthis californiana [up-->]Opisthoteuthis calypso [up-->]Opisthoteuthis philipii [up-->]Opisthoteuthis hardyi [up-->]Opisthoteuthis grimaldii [up-->]Opisthoteuthis albatrossi [up-->]Opisthoteuthis agassizii [up-->]Opisthoteuthis persephone [up-->]Opisthoteuthis robsoni [up-->]Opisthoteuthis pluto [up-->]Opisthoteuthis chathamensis [up-->]Opisthoteuthis massyae [up-->]Opisthoteuthis mero [up-->]Opisthoteuthis dongshaensis [up-->]Opisthoteuthis extensa [up-->]Opisthoteuthis medusoides [up-->]Opisthoteuthis depressa [up-->]Opisthoteuthis borealis [down<--]Opisthoteuthidae Interpreting the tree
close box

This tree diagram shows the relationships between several groups of organisms.

The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.

example of a tree diagram

You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.

For more information on ToL tree formatting, please see Interpreting the Tree or Classification. To learn more about phylogenetic trees, please visit our Phylogenetic Biology pages.

close box
Containing group: Opisthoteuthidae


Species of Opisthoteuthis are the most compressed, in the anterior-posterior axis, of any cephalopod. This flattened appearance (due sometimes to preservation) gives them the common name of flapjack or pancake devilfish. Fresh specimens have ovoid form. Species are thought to be primarily benthic although they are capable of swimming and in some species the swimming may be an important component of their pouncing on minute prey. As in other cirrates, most species are poorly known.

An introduction to an Opisthoteuthis is seen in this video.

From Stephanie Bush, "The Opisthoteuthis eggs depicted in this video are preserved specimens, not the eggs laid at the Monterey Bay Aquarium (which are still being lovingly incubated at MBARI's Cold Storage Facility!.)" 

Brief diagnosis:

An opisthoteuthid ...

Full diagnosis of the more restrictive use of the genus (from Collins and Villanueva, 2006):

Moderate-sized cirrates with small, subterminal fins. Shell a flaring U-shape, lateral walls tapering to fine points. Optic nerves pass through white body in two to four bundles. Two fields of enlarged suckers in mature males. Digestive gland entire or bilobed. Radula and posterior salivary glands absent. Web deep, single. Gills of ‘half-orange’ form.*

*Collins and Villanueva (2006) use this same diagnosis to define their family Opisthoteuthidae which contains this single genus.


  1. Arms and web
    1. Arms of males generally with modified suckers (i.e., enlarged and often with complex alignment) in one or two fields (proximal and distal).
    2. Cirri short (in preserved animals).
    3. Cirri may be retractile into pockets. The retractile (rather than just contractile) nature of the cirri has been suggested by several authors due to their appearance in preserved animals. However, this attribute remains uncertain.
    4. Web nodules (= web supports; these are often difficult to detect) present as multiple or single nodules or absent. 
      Click on an image to view larger version & data in a new window
      Click on an image to view larger version & data in a new window

      Figure. Oral view of Opisthoteuthis grimaldii (?). Photograph shows multiple web nodules, some of which are indicated by the arrows. Also note the rather long cirri in this live Opisthoteuthis. Photograph from a submersible.

  2. Head
    1. Eyes large, diameter often 60-70% of ML, 50% of head width.
    2. Two or more bundles of optic tract penetrate white body.
    3. Optic lobe kidney-shaped in cross-section.
    4. Beaks: Descriptions can be found here: Lower beak; upper beak.

  3. Fins
    1. Small, length approximately half mantle width.

  4. Shell
    1. U-shaped, lateral walls (=wings) not parallel (i.e., spread between walls increases toward tips).
    2. Outer surface of saddle usually with groove (narrow or broad, shallow or deep); outer surface rarely flat.
    3. Wing frequently terminates as elongate, simple, pointed cone; termination complex in some species.

    4. Although the shell lies at an angle to the body axis, the variation in the angle of the spread of its lateral walls presumably is a measure of the "flatness" (i.e., compression of the anterior-poterior body axis) of the octopod.

      The extreme flatness of some Opisthoteuthis is apparent in this video.

  5. Pigmentation
    1. Areolar spots present. In some species these are difficult to detect or absent.
      Click on an image to view larger version & data in a new window
      Click on an image to view larger version & data in a new window

      Figure. Side view of Opisthoteuthis agassizii. Photograph from submersible. In this photograph, the lines of white areolar spots are easily seen, especially on the arms.

  6. Viscera
    1. Gills with "half-orange" form.
    2. Intestine approximately 1.5 - 2.0 times esophagus (and crop) in length. Digestive tract not a simple loop (i.e., intestine makes lateral bends and/or loops.
    3. Digestive gland bilobed or unilobed.
    4. Radula absent.

Species Comparisons (from Villanueva et al., 2002, Villanueva et al., 2008 and Lu, 2010)

  Mature males Both sexes
Species Arm I more robust Prox. field: No. of suckers Distal field: No. of suckers Prox. field: Arm no. Distal field: Arm no. Distal field: Largest sucker, mean position DESD> PESD ** Arm sucker counts Funnel organ Web supports Digest. gland bilobed Ocean
O. agassizii  No  5  7-8  I-IV  I-IV  34-36  No/yes  58-80  V-shape  Multiple  No  W.N.Atlantic
O. albatrossi  No  0  3  None  I  ?  Yes  80  ?  Single?  Yes  N. Pacific
O. borealis  Slight  5  9-14  I-IV  I-IV  27-30  Equal  75-82  ?  No  No  N. Atlantic
O. bruuni No 3 2-3 I-IV I-IV 24-27* No ? 2 pads ? ? E. S. Pacific
O. californiana No 8-10 3-8 I-IV I ca. 27 Yes ? 2 pads ? ? N. Pacific
O. calypso No 2-6 2-3 III I-IV 26-27 Yes 47-58 2 pads Single No E. Atlantic
O. chathamensis No 5-7 6-8 I-IV I-IV ca 22 Equal? 41-55 V-shape ? Yes W. S. Pacific
O. depressa No 16 0 I-IV None -- No 50 ? Absent? ? W. N. Pacific
O. extensa ? ? ? ? ? ? ? ? ? ? ? E. Indian
O. grimaldii No 4-11 9-10 I-IV I-IV 29-31 No 73-80 2 pads Single Yes E. Atlantic
O. hardyi Slight 4-9 9-14 I-IV I-IV 22-24 Equal 60-67 ? Absent No high S. Atlantic
O. japonica  No  9  ?  I-IV  ?  --  No  ?  2 pads  ?  ?  W.N. Pacific
O. massyae Yes 7-8 9-11 I-IV II-IV 40-41 No 81-106 2 pads Multiple Yes E. Atlantic
O. medusoides ? ? ? ? IV ? ? ? ? ? ? W. Indian
O. mero No 5-8 ? I-IV None -- No 54-71 V-shape ? Yes W. S. Pacific
O. persephone No 3-8 4-7 I-IV I & II
31-34 No 68-81 V-shape Absent Yes Off S. Aust.
O. philipii ? 5-11 ? ? ? ? ? ? V-shape Single ? NW Indian
O. pluto Yes 3-6 2-4 I-IV II-IV 29-34 yes male/no female
59-88 V-shape Absent Yes Off S. Aust.
O. robsoni No 7-8 ? I-IV None -- No 74-89 V-shape ? No W. S. Pacific
O. dongshaensis
Yes 3-4
N.W. Pacific

*From illustration. ** DESD = Distal field enlarged sucker diameter; PESD = Proximal field enlarged sucker diameter. For the purposes of this table, a distal field is considered to be absent if suckers there do not show a distinct enlargement.


Cirroteuthis caudani Joubin, 1896 appears to be a species of Opisthoteuthis [probably O. grimaldii or O. massyae according to Martin Collins, pers. comm., 2002] but the type is apparently lost (Villanueva et al., 2002)

Other Names for Opisthoteuthis Verrill 1883


Chun, C. 1915. Die Cephalopoden. Myopsida, Octopoda. Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expedition, "Valdivia" 1898-1899, 18 (2): 405-522 + Atlas.

O'Shea, Steve. 1999. The Marine Fauna of New Zealand: Octopoda (Mollusca: Cephalopoda). NIWA Biodiversity Memoir 112: 280pp.

Sweeney, M.J. 2001. Current Classification of Recent Cephalopoda. pdf file, 59 pp.

Villanueva, R., Collins, M., Sanchez, P. and N. Voss. 2002. Systematics, distribution and biology of the cirrate octopods of the genus Opisthoteuthis (Mollusca, Cephalopoda) in the Atlantic Ocean, with description of two new species. Bulletin of Marine Science 71(2):933-985.

Villanueva R., R.E. Young, M. Vecchione. 2008. Opisthoteuthis Verrill 1883. Flapjack devil shes. Version 28 Apr. 2008 (under construction). Available at http://tolweb.org/Op isthoteuthis/20106/2008.04.28 in The Tree of Life Web Project, http://tolweb.org/.

Voss, G. L. and W. G. Pearcy. 1990. Deep-water octopods (Mollusca: Cephalopoda) of the Northeastern Pacific. Proc. Calif. Acad. Sci. 47: 47-94.

Title Illustrations
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
Scientific Name Opisthoteuthis sp
Location Photographied under aquarium conditions (Monterey Bay Aquarium)
Creator Photo by David Wrobel
Specimen Condition Live Specimen
Sex Female
View lateral
Copyright © Monterey Bay Aquarium
About This Page

Instituto de Ciencias del Mar (CSIC), Barcelona, Spain

University of Hawaii, Honolulu, HI, USA

National Museum of Natural History, Washington, D. C. , USA

All Rights Reserved.

Citing this page:

Villanueva, Roger, Richard E. Young, and Michael Vecchione. 2016. Opisthoteuthis Verrill 1883. Flapjack devilfishes. Version 27 February 2016 (under construction). http://tolweb.org/Opisthoteuthis/20106/2016.02.27 in The Tree of Life Web Project, http://tolweb.org/

edit this page
close box

This page is a Tree of Life Branch Page.

Each ToL branch page provides a synopsis of the characteristics of a group of organisms representing a branch of the Tree of Life. The major distinction between a branch and a leaf of the Tree of Life is that each branch can be further subdivided into descendent branches, that is, subgroups representing distinct genetic lineages.

For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.

close box


Page Content

articles & notes



Explore Other Groups

random page

  go to the Tree of Life home page