Cephalopod Primary and Secondary Webs

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

Cephalopoda Glossary

In cirroteuthid and stauroteuthid octopods, portions of the web between the arms have a special modification called the secondary web. This secondary web allows the arm to extend orally while the expanded primary web, inflated by surounding a large volume of water, remains aborally positioned. The definitions of the primary and secondary webs are illustrated in the arm and web cross-sections below left. Below right is a photograph taken of a cirrate near the ocean floor. The upcurved arms clearly show the secondary web which, incorrectly, appears as a membrane separate from the web.

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Figure. Left - Cross-sections of the arms and web of Stauroteuthis syrtensis, which has a secondary web, and Cirroctopus glacialis, which lacks a secondary web. Drawings modified from Vecchione and Young (1997). Right - Posterior view of a cirrate with arms spread. Photograph from Roper and Brundage (1972).


Roper, C.F.E. and Brundage Jr., W. 1972. Cirrate octopods with associated deep-sea organisms: new biological data based on deep benthic photographs (Cephalopoda). Smithsonian Contributions to Zoology, 121:1-46.

Vecchione, M. and R. E. Young. 1997 Aspects of the functional morphology of cirrate octopods: locomotion and feeding. Vie Milieu 47(2):101-110.

About This Page

University of Hawaii, Honolulu, HI, USA

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

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

Page: Tree of Life Cephalopod Primary and Secondary Webs Authored by Richard E. Young, Michael Vecchione, and Katharina M. Mangold (1922-2003). 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.

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