Chiroteuthid families
Richard E. Young and Michael Vecchione
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close boxIntroduction
Chiroteuthid families are a group of seven families that share some similar features but whose inclusion as a monophyletic clade has not been firmly established. The most distinctive feature of the group is the loss of the true tentacle club and its replacement by a variety of unusual clubs that generally have more than four series of suckers.
Diagnosis
An oegopsid ...
- without primary tentacular club (possible exception in Planctoteuthis).
- with secondary tentacular club.
Characteristics
- Arms
- Suckers generally in two series (exceptions in Joubiniteuthidae and some Promachoteuthidae).
- Buccal connectives attach to ventral borders of arms IV.
- Tentacles
- Primary club apparently lost except in Planctoteuthis; secondary club present and characterized by:
- Protective membranes of club symmetrical (ie, dorsal and ventral membranes identical) when present.
- Keel absent.
- Terminal pad absent.
- Club not expanded.
- Club straight.
- Funnel
- Locking-apparatus oval in most taxa but often with inward protruding knobs (tragus and antitragus) or other bumps making appearance highly variable.
image infoFigure. Ventral view of a funnel locking-apparatus of Chiroteuthis joubini. Drawing by A. Hart modified.
- Locking-apparatus oval in most taxa but often with inward protruding knobs (tragus and antitragus) or other bumps making appearance highly variable.
- Fins
- Fins usually terminal (muscular mantle terminates in anterior half of fins).
- Tail
- A tail, often very long, and supported by the secondary conus of the gladius, generally present.
Discussion of Phylogenetic Relationships
The relationships among the families of this apparent clade are obscure with one exception. The Chiroteuthididae and Mastigoteuthididae have sometimes been placed within the same family due to similarities in the shape of the funnel locking-apparatus and the presence of elongate arms IV (e.g., Chun, 1910).
References
Chun, C. 1910. Die Cephalopoden. Oegopsida. Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expedition, "Valdivia" 1898-1899, 18: 1-522 + Atlas.
Title Illustrations
| Scientific Name | Batoteuthis scolops, Chiroteuthis veranyi, Joubiniteuthis portieri, Magnapinna pacifica, Mastigoteuthis glaukopis, Promachoteuthis megaptera |
|---|---|
| Acknowledgements | Batoteuthis scolops illustration by A. D. Hart, Chiroteuthis veranyi photograph copyright ? 1996, E. McSweeny, Joubiniteuthis portieri photograph copyright ? 1996, R. E. Young, Megapinna pacifica photograph copyright ? 1998, Richard E. Young), Mastigoteuthis glaukopis from Chun, 1910, Promachoteuthis megaptera from Okutani, 1983. |
| Copyright | © 1996 Richard E. Young |
About This Page
Richard E. Young
Dept of Oceanography
University of Hawaii
Honolulu, Hawaii 96822
USA
National Marine Fisheries Service
Systematics Laboratory
National Museum of Natural History
Washington, D. C. 20560
USA
Page copyright © 1996 Richard E. Young
Citing this page:
Young, Richard E. and Vecchione, Michael. 1996. Chiroteuthid families. Version 01 January 1996 (under construction). http://tolweb.org/Chiroteuthid_families/19410/1996.01.01 in The Tree of Life Web Project, http://tolweb.org/
