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Heteroteuthinae Appellof, 1898

Richard E. Young, Clyde F. E. Roper, and Michael Vecchione
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taxon links [up-->]Stoloteuthis [up-->]Sepiolina [up-->]Heteroteuthis [up-->]Amphorateuthis alveatus [up-->]Nectoteuthis [up-->]Sepiolina [up-->]Iridoteuthis Monophyly Uncertain[down<--]Sepiolidae Interpreting the tree
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Containing group: Sepiolidae

Introduction

Heteroteuthins are small pelagic or benthopelagic sepiolids. They are easily recognized by their silvery sides and colorful ventral shield. The latter structure appears to be involved in diffusing the light from their large visceral photophore.

Brief diagnosis:

A sepiolid with ... 

Characteristics


  1. Arms
    1. Interbrachial web strongly developed connecting proximal halves of arms I-III.
    2. Arm suckers biserial except tips of arms IV where they may become more numerous.

  2. Tentacles
    1. Tentacular clubs not expanded (except in Sepiolina).
    2. Keel present only at base of club as narrow elongate fold, paired with a reduced dorsal protective membrane to form "tentacle organ" (except in Sepiolina) of unknown function.
      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. Oral view of tentacular club of Heteroteuthis sp. showing the "tentacle organ" at the club base. Drawing by A. Hart.

  3. Mantle
    1. Ventral mantle margin projects anteriorly.
    2. Ventral mantle modified optically and morphologically to form "ventral shield." Outside of the Heteroteuthinae a "shield" is found only in Choneteuthis tongaensis.
      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-oblique view of Iridoteuthis iris showing ventral shield. Photograph by Thomas Burch.

    3. Mantle fused to or free from head in nuchal region.

  4. Gladius
    1. Gladius absent.

  5. Viscera
    1. Bursa copulatrix absent.

  6. Photophores
    1. Single visceral photophore (with large circular "lens") on ventral surface of ink sac.

Comments

The ventral shield on the mantle is thought to diffuse the light from the visceral photophore over the region of the shield and thereby aid in counterillumination (eliminate the shadow of the animal created by dim downwelling light). No expermental evidence exists, however, to support this assumption.

The following table compares the six genera.

  Tentacle organ Arm modifications in males Enlarged suckers, males Mantle-head fusion Funnel locking-apparatus Length of ventral shield Posterior fin lobes 
Heteroteuthis Proximal to sucker-bearing club
 Strong asymmetry of right arms I & II.  Right arm II with glands Arms III None Deep curved goove 50% VML Rounded 
Iridoteuthis Along much of sucker-bearing club
 No strong asymmetry, no glands Complex or none
 Broad Straight or curved groove and deep, angular pit >80% VML Angled 
Nectoteuthis Unknown No asymmetry, arm suckers tubular, glands unknown Unknown None Groove with two pits: Deep, broad anterior; shallow posterior >80% VML Rounded 
Amphorateuthis Along much of sucker-bearing club No asymmetry, arm suckers tubular in males. No glands
 Arms III Broad Straight groove and deep anterior pit >80% Angled 
Sepiolina Absent No asymmetry. Arms I with glands Arms II & III Narrow Elongate anterior pit and short groove >80% VML Rounded
Stoloteuthis Proximal to sucker-bearing club or barely overlapping
 No asymmetry. Arms I with  glands Arms II Narrow, broad or none
 Straight groove >80% VML Rounded or angled
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
Location Hawaiian waters
Specimen Condition Live Specimen
View Side
Size 19 mm ML
Copyright © 1996 Thomas Burch
Scientific Name Heteroteuthis hawaiiensis
Location Hawaiian waters
View Side
Image Use creative commons This media file is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0.
Copyright © 2004
About This Page


University of Hawaii, Honolulu, HI, USA


Smithsonian Institution, Washington, D. C., USA


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

Page: Tree of Life Heteroteuthinae Appellof, 1898. Authored by Richard E. Young, Clyde F. E. Roper, 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., Clyde F. E. Roper, and Michael Vecchione. 2015. Heteroteuthinae Appellof, 1898. Version 04 November 2015 (under construction). http://tolweb.org/Heteroteuthinae/20027/2015.11.04 in The Tree of Life Web Project, http://tolweb.org/

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