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Octopoda Leach, 1818

Octopods or devilfishes

Katharina M. Mangold (1922-2003), Richard E. Young, and Michael Vecchione
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Containing group: Octopodiformes

Introduction

Comments on this page refer to living Octopoda. for comments on extinct Octopoda see: Teudopseina and Incirrata.

Octopods have rather short, compact bodies and only eight arms; no trace of the missing second arm pair remains even during embryonic development. Many species are benthic (bottom-living) and crawl over the ocean floor with the mouth facing the substratum. Others alternate between a benthic and a pelagic (free-swimming) habitat and some species are completely pelagic. The two suborders of Octopoda are very different in appearance but there is little doubt that it is a natural group as the monophyly of the Octopoda is supported by a large variety of characters. The Cirrata is a group of deep-sea octopods commonly known as the "finned octopods" due to their large, wing-like fins. The Incirrata contain the common (benthic), shallow-water octopods as well as many deep-sea benthic and pelagic species.

Brief diagnosis:

An octopodiform ...

Characteristics

  1. Arms
    1. Suckers with cuticular lining.
    2. Sucker stalks are broad, muscular cylinders.

  2. Head
    1. Nuchal cartilage absent.
    2. Inferior frontal lobe system present; superior buccal and posterior buccal lobes fused; suprabrachial commissure separate from brain (absent in Japetella).

  3. Funnel
    1. Funnel valve absent.

  4. Viscera
    1. Visceropericardial coelom reduced.
    2. Oviducal glands act, in part, as spermathecae.
    3. Oviducts with oviducal glands subterminally located on oviducts.
    4. Photosensitive vesicles located on stellate ganglia.
    5. Dorsal mantle cavity present.

Discussion of Phylogenetic Relationships

The monophyly of both suborders is well established. Young and Vecchione (1996) found two apomorphic character states that defined the monophyly of the Incirrata:

Another character can probably be added to the list of apomorphies although it hasn't been included in a cladistic study:

Young and Vecchione (1996) found three character states that defined the monophyly of the Cirrata:

Voight (1997) also found morphological, cladistic support for the Cirrata and Incirrata but her study is controversial. Carlini (1998) found molecular analyses supported the monophyly of both groups.

Other Names for Octopoda Leach, 1818

References

Carlini, D. B. 1998. The phylogeny of coleoid cephalopods inferred from molecular evolutionary analyses of the cytochrome oxidase I, muscle actin, and cytoplasmic actin genes. Ph.D. diss. Coll. William and Mary, 273 pp.

Young, R. E. and M. Vecchione. 1996. Analysis of morphology to determine primary sister taxon relationships within coleoid cephalopods. Amer. Malac. Bull. 12: 91-112.

Young, R. E., M. Vecchione and D. Donovan. 1999. The evolution of coleoid cephalopods and their present biodiversity and ecology. South African Jour. Mar. Sci. (in press).

Voight, J. R. 1997. Cladistic analysis of the octopods based on anatomical characters. J. Moll. Stud., 63: 311-325.

Title Illustrations
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Click on an image to view larger version & data in a new window
Scientific Name Octopus
Location Hawaii
Life Cycle Stage young
About This Page

Katharina M. Mangold (1922-2003)
Laboratoire Arago, Banyuls-Sur-Mer, France


University of Hawaii, Honolulu, HI, USA


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

Page: Tree of Life Octopoda Leach, 1818. Octopods or devilfishes. Authored by Katharina M. Mangold (1922-2003), Richard E. Young, and Michael Vecchione. The TEXT of this page is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.

Citing this page:

Mangold (1922-2003), Katharina M., Richard E. Young, and Michael Vecchione. 2010. Octopoda Leach, 1818. Octopods or devilfishes. Version 03 May 2010 (under construction). http://tolweb.org/Octopoda/20083/2010.05.03 in The Tree of Life Web Project, http://tolweb.org/

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