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Argonautoidea Naef, 1912

Richard E. Young and Michael Vecchione
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Four families comprise a well-defined monophyletic clade.
taxon links [up-->]Alloposidae [up-->]Argonautidae [up-->]Tremoctopodidae [up-->]Ocythoidae [down<--]Incirrata Interpreting the tree
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Containing group: Incirrata

Introduction

All four families of the Argonautoidea are pelagic although one (Alloposidae) is "associated" with the ocean floor. The families are primarily distinguished by an unusual means of copulation which involves transferring a detached hectocotylus from the male to the female. The clade includes gelatinous species as well as very muscular species.

Brief diagnosis:

An incirrate octopod ...

Characteristics

  1. Arms
    1. Arm suckers in two series (grade to single series near mouth in Haliphron).
    2. One of third arm pair entirely hectocotylized and enrolled in a sac or pouch prior to use.
    3. Hectocotylized arm autotomizes (i. e., detaches) during copulation.
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      Figure. Detached hectocotylus of Argonauta argo found wiggling among contents of a midwater trawl. Photograph (overexposed) by M. Vecchione.

  2. Funnel
    1. Funnel-locking apparatus well developed but structure differs among families.

  3. Sexual dimorphism
    1. Males much smaller than females; males dwarfs in three families.

  4. Shell
    1. Internal shell present only in Alloposidae; shell lost in other families.

  5. Radula
    1. Radula heteroglossan.

Discussion of Phylogenetic Relationships

Naef (1923) suggested that the argonautoid families were derived from the Octopodidae and presented a phylogeny, shown above in the title frame, based on the characteristics of the hectocotylus.

Voight (1997), in a cladistic study using mostly different characters, presented a less resolved phylogeny:


\ ------ Alloposidae
\ / ----- Argonautidae
\/ /
\/------ Ocythoidae
\
\----- Tremoctopodidae

Other Names for Argonautoidea Naef, 1912

References

Naef, A. 1921/23. Cephalopoda. Fauna und Flora des Golfes von Neapel. Monograph, no. 35.

Nesis, K. N. 1982. Abridged key to the cephalopod mollusks of the world's ocean. 385+ii pp. Light and Food Industry Publishing House, Moscow. (In Russian.). Translated into English by B. S. Levitov, ed. by L. A. Burgess (1987), Cephalopods of the world. T. F. H. Publications, Neptune City, NJ, 351pp.

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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Scientific Name Argonauta nodosa, Haliphron atlanticus, Ocythoe tuberculata, Tremoctopus violaceus
Acknowledgements courtesy of Mark Norman
Copyright © 1996 David Paul (Argonauta), Ron Gilmer (Haliphron), Dorothy Petersen (Ocythoe), M. Vecchione (Tremoctopus)
About This Page


University of Hawaii, Honolulu, HI, USA


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

Page: Tree of Life Argonautoidea Naef, 1912. Authored by 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:

Young, Richard E. and Michael Vecchione. 2008. Argonautoidea Naef, 1912. Version 21 October 2008. http://tolweb.org/Argonautoidea/20192/2008.10.21 in The Tree of Life Web Project, http://tolweb.org/

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