Under Construction

Enoploteuthid families

Richard E. Young and Michael Vecchione
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
taxon links [up-->]Ancistrocheiridae [up-->]Lycoteuthidae [up-->]Pyroteuthidae [up-->]Enoploteuthidae [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

Four families show close relationships and are placed here in a clade "enoploteuthid families." A formal name is premature, however, until the position of the clade within the Oegopsida and confirmation of the monophyletic nature of the group at this position can be confirmed.

Members of this clade are small squids that occupy the mesopelagic zone of the ocean and have an abundance of photophores. Three of the four families have hooks on the arms and, usually, tentacles.

Brief diagnosis:

An oegopsid ...

Characteristics

  1. Arms
    1. Armature in two series.
    2. Arm hooks present except in Lycoteuthididae.
      1. Aperature absent (except for small aperature in Enoploteuthis).
      2. Belly of hook with ridge (except in Pterygioteuthis).
      3. Margin of hook base with 2 large lateral lobes and 1 proximal lip.
      4. Skirt absent.
      5. Accessory hooks absent.
      **See Cephalopod Hooks for hook terminology.

  2. Tentacles
    1. Armature on tentacular clubs in four series in young but may be reduced on manus in subadults.
    2. Club hooks present except in Lycoteuthidae and Pterygioteuthis.
    3. Proximal (= carpal) locking-apparatus of tentacle compact, often circular.

  3. Buccal crown
    1. Buccal crown with eight or remnants of eight buccal supports.
    2. Buccal-crown connectives attach to dorsal margins of arms IV.

  4. Photophores
    1. Numerous photophores present but distribution varies between families.

  5. Spermatangia attachment-sites
    1. Spermatangia attach to specialized tissue in nuchal region (except Enoploteuthis).

  6. Gladius
    1. Gladius with conus and elongate conus field.

Comments

The following table compares characteristics of subadults of the families of the enoploteuthid families.

  Ancistrocheiridae
Enoploteuthidae
Lycoteuthidae
Pyroteuthidae
Photophores on/in tentacles
Yes
No
Yes
Yes
Photophores on mantle
Yes
Yes
No
No
Photophores on viscera
No
No
Yes
Yes
Photophores on eyeballs
No
Yes
Yes
Yes
Hooks on arms I-III
Yes
Yes
No
Yes

Discussion of Phylogenetic Relationships

Young and Harman (1998) in a morphological, cladistic study demonstrated that the relationship between the Lycoteuthididae and the Pyroteuthididae was closer than the relationship between the Pyroteuthididae and the Enoploteuthididae. This conclusion favored the breakup, as proposed by Clarke (1988), of the former Enoploteuthididae which had included the subfamilies Pryoteuthidinae, Ancistrocheiridinae and Enoploteuthidinae. Among the features that support a sister-group relationship between the Pyroteuthididae and Lycoteuthididae is the remarkable similarity in the structure and the position of the photophores (the structural similarity was first noted by Herring et al., 1985).

Support for a Enoploteuthid-Lycoteuthid-Pyroteuthid clade was provided by the shared presence of:

The sister-group relationship of the Lycoteuthidae and Pyroteuthidae was supported by:

The study suffers primarily from polarization uncertainities due to poor understanding of outgroup relationships. The study suggests that the pyroteuthids have diverged strongly in morphology from their nearest relatives.

References

Clarke, M. R. 1988. Evolution of recent cephalopods -- A brief review. P. 331-313. In: Clarke, M. R. and E. R. Trueman (Eds.). The Mollusca. Vol. 12. Paleontology and Neontology of Cephalopods. Academic Press, New York. 355pp.

Herring, P. J., P. N. Dilly and C. Cope. 1985. The photophore morphology of Selenoteuthis scintillans Voss and other lycoteuthids. J. Zool. Lond., 206: 567-589.

Young, R. E. and R. Harman. 1998. The phylogeny of the "enoploteuthid families." Smithson. Contr. Zool., No. 586: 257-270.

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 Ancistrocheirus lesueurii, Abralia trigonura, Selenoteuthis scintillans, Pyroteuthis addolux
Comments Ancistrocheirus lesueurii, drawing modified from Okutani, 1974. Selenoteuthis scintillans photograph by M. Vecchione. Abralia trigonura and Pyroteuthis addolux photographs by R. Young
Reference Ancistrocheirus lesueurii, drawing modified from Okutani, 1974.
Image Use creative commons This media file is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0.
Copyright © 1996
About This Page


University of Hawaii, Honolulu, HI, USA


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

Page: Tree of Life Enoploteuthid families. 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. 2015. Enoploteuthid families. Version 04 November 2015 (under construction). http://tolweb.org/Enoploteuthid_families/19413/2015.11.04 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

Enoploteuthid families

Page Content

articles & notes

collections

people

Explore Other Groups

random page

  go to the Tree of Life home page
top