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Oegopsida Orbigny, 1845

Richard E. Young and Michael Vecchione
taxon links [down<--]Decapodiformes [up-->]Architeuthidae [up-->]Ommastrephidae [up-->]Brachioteuthidae [up-->]Chiroteuthid families [up-->]Cranchiidae [up-->]Cycloteuthidae [up-->]Enoploteuthid families [up-->]Gonatidae [up-->]Histioteuthid families [up-->]Lepidoteuthid families [up-->]Neoteuthidae [up-->]Onychoteuthidae [up-->]Thysanoteuthidae Interpreting the tree
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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.

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Containing group: Decapodiformes


Among cephalopods, oegopsid squids dominate the pelagic, oceanic environment. Diversity at the family and generic levels is very high with 24 families and 69 genera. Although pelagic, some species are consistently associated with and some occasionally sit on the ocean floor.


Decapodiforms ...


  1. Arms
    1. Suckers without circularis muscles.

  2. Tentacles
    1. Tentacular club usually with carpal (= proximal) locking-apparatus.
    2.  image info

      Figure. Oral view of the club base of Cycloteuthis serventyi. The red line encircles the suckers and knobs of the carpal locking-apparatus. Drawing modified from Young and Roper (1969).

    3. Suckers without circularis muscles (see Sepioidea page).

  3. Buccal crown
    1. Buccal supports lack suckers.

  4. Head
    1. Head without tentacle pockets.
    2. Eyes without corneal membranes covering lenses.
       image info

      Figure. Dorsal view of the head of Pyroteuthis addolux with the protruding eye lenses directly exposed to sea water. Photograph by R. Young.

  5. Funnel
    1. Funnel without lateral adductor muscles.

  6. Mantle
    1. Mantle locking-apparatus, with rare exceptions, reaches anterior mantle margin.

  7. Fins
    1. Fins usually joined posteriorly and usually without posterior lobes.
       image info

      Figure. Ventral view of mantle and fins of Ancistroteuthis lichtensteini, 175 mm ML, Mar-Eco cruise, R/V G. O. SARS, North Atlantic. Photograph by R. Young.

  8. Shell
    1. Shell a gladius.

  9. Viscera
    1. Gills with branchial canal.
       image info

      Figure. Diagramatic cross-section through gills. Drawing modified from Naef (1921-23).

    2. Oviducts paired.
    3. Females without accessory nidamental glands.

  10. Eggs
    1. Eggs in pelagic egg masses.


Comparisons of the major groups of the Oegopsida

Buccal connective to arms IV Funnel locking-cartilage Carpal locking-apparatus Gladius conus Anterior fin attachment
Architeuthidae Dorsal Straight Yes 1° conus Mantle
Brachioteuthidae Ventral Straight Yes/No 2° conus Gladius
Chiroteuthid families Ventral Variable, usually oval, often with knobs No 2° conus Gladius
Cranchiidae Ventral Fused Yes 2° conus /No Gladius/Mantle
Cycloteuthidae Ventral Triangular Yes 2° conus /No Gladius
Enoploteuthid families Dorsal Straight Yes 1° conus Gladius
Gonatidae Ventral Straight Yes 1° conus Gladius
Histioteuthidae families Dorsal Straight Yes No Gladius
Lepidoteuthidae families Ventral Straight No 2° conus Gladius
Neoteuthidae Dorsal Straight Yes 1° conus Mantle
Ommastrephidae Dorsal Inverted T Yes/No 1° conus Gladius
Onychoteuthidae Ventral Straight Yes 1° conus Gladius
Thysanoteuthidae Ventral Lazy T Yes No Mantle

A key to the families of the Decapodiformes can be found here.


Title Illustrations
Scientific Name Pyroteuthis margaritifera, Promachoteuthis sp., Magnapinna ?, Helicocranchia pfefferi, Joubiniteuthis portieri, Onychoteuthis sp., Todarodes sagittatus
Acknowledgements J. portieri photograph by Frank Parish; Magnapinna (?) photograph from N.U.R.C., others photographed by R. Young.
Copyright © 2004 Richard E. Young
About This Page

Richard E. Young

Dept of Oceanography
University of Hawaii
Honolulu, Hawaii 96822

National Marine Fisheries Service
Systematics Laboratory
National Museum of Natural History
Washington, D. C. 20560

Citing this page:

Young, Richard E. and Vecchione, Michael. 2004. Oegopsida Orbigny, 1845. Version 18 August 2004 (under construction). http://tolweb.org/Oegopsida/19407/2004.08.18 in The Tree of Life Web Project, http://tolweb.org/

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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.

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