Under Construction

Cycloteuthidae Naef, 1923

Richard E. Young
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
The Cycloteuthidae contains two rather dissimilar genera.
taxon links [up-->]Discoteuthis [up-->]Cycloteuthis [down<--]Oegopsida Interpreting the tree
close box

This tree diagram shows the relationships between several groups of organisms.

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.

example of a tree diagram

You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.

For more information on ToL tree formatting, please see Interpreting the Tree or Classification. To learn more about phylogenetic trees, please visit our Phylogenetic Biology pages.

close box
Containing group: Oegopsida

Introduction

Cycloteuthids are mesopelagic squids of moderate size, the largest reaches about 60 cm ML, with a cosmopolitan distribution in tropical and subtropical waters (Nesis, 1982). In Cycloteuthis the mantle and fins are drawn-out into a slender tail. A tail is lacking in Discoteuthis and the large, oval (disc-like) combined fins extend virtually the full length of the mantle. Very little is known about the biology of any species in the family.

Brief diagnosis:

An oegopsid ...

Characteristics

  1. Arms
    1. Arm suckers biserial.
    2. Buccal-crown connectives attach to ventral borders of Arms IV.

  2. Tentacles
    1. Tentacular club with quadraserial suckers.

  3. Funnel/mantle locking apparatus
    1. Funnel component with sub-triangular groove.
    2. Mantle component does not reach anterior mantle margin.
    Click on an image to view larger version & data in a new window
    Click on an image to view larger version & data in a new window

    Figure. Ventral views of the funnel locking-apparatus of C. serventyi (left) and the two species of Discoteuthis (right).

Comments

The genera are easily separated by body and fin shape (see title illustrations).  In addition the presence of a large visceral photophore only in Cycloteuthis allows genera to be separated when badly damaged.

Nomenclature

A list of all nominal genera and species in the Cycloteuthidae can be found here. The list includes the current status and type species of all genera, and the current status, type repository and type locality of all species and all pertinent references.

Discussion of Phylogenetic Relationships

The features that unites these two genera is the similar triangular shape of the funnel locking-apparatus and the position of the mantle component. Other than these unusual features, there is little morphological evidence for their close relationship. Molecular evidence (Carlini, 1998), however, supports their close relationship.

 ANNIE- DISSERTATION; SUPER TREE  !!!

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.

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.

Young, R. E. and C. F. E. Roper. 1969. A monograph of the Cephalopoda of the North Atlantic: The family Cycloteuthidae. Smithsonian Contributions to Zoology No. 5:1-24.

Title Illustrations
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
Scientific Name Cycloteuthis serventyi, Discoteuthis discus (2)
Reference Young, R. E. and C. F. E. Roper. 1969. A monograph of the Cephalopoda of the North Atlantic: The family Cycloteuthidae. Smithsonian Contributions to Zoology No. 5:1-24.
View Ventral
Size 42, 53 mm ML
Image Use creative commons This media file is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0.
Copyright ©
About This Page


University of Hawaii, Honolulu, HI, USA

Page: Tree of Life Cycloteuthidae Naef, 1923. Authored by Richard E. Young. 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. 2012. Cycloteuthidae Naef, 1923. Version 10 November 2012 (under construction). http://tolweb.org/Cycloteuthidae/19412/2012.11.10 in The Tree of Life Web Project, http://tolweb.org/

edit this page
close box

This page is a Tree of Life Branch Page.

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.

close box

Cycloteuthidae

Page Content

articles & notes

collections

people

Explore Other Groups

random page

  go to the Tree of Life home page
top