Under Construction

Sepiolidae Leach 1817

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
taxon links [up-->]Sepiolinae [up-->]Heteroteuthinae [up-->]Rossiinae [up-->]Choneteuthis tongaensis [up-->]New Subfamily Phylogenetic position of group is uncertain[down<--]Sepiolida 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

The phylogenetic tree is based on relationships suggested by Naef (1923) and conjecture based on comments given below.

Containing group: Sepiolida

Introduction

Sepiolids are small (ca. 1-10 cm ML), broad cephalopods with a rounded posterior mantle and ear-like fins. Species of the Rossinae and Sepiolinae are benthic while those of the Heteroteuthinae are pelagic. The most distinctive group is the Heteroteuthinae in which the ventral mantle margin extends beneath the head, and the photophores are fused into a single large organ. All sepiolids, where known, lay large benthic eggs and the young hatch out at an advanced stage of development and their length may be one quarter of that of the adult female (Naef, 1921-23).

Diagnosis

A Sepiolida ...

Characteristics

  1. Arms
    1. Any or all of the dorsal six arms may be hectocotylized.

  2. Funnel
    1. Funnel locking-apparatus often with an elongate, broad groove, but considerable variability may exist.

  3. Mantle
    1. Dorsal margin fused to or free from head.

  4. Shell
    1. Shell a thin or rudimentary gladius or absent.

Comments

The following table compares the three subfamilies.

  Mantle fused to head Head with nuchal cartilage Mantle with ventral shield Extensive web between arms I-III Lateral funnel adductor muscles 
Choneteuthis Yes Yes Yes
No Yes 
Heteroteuthinae Yes/No Yes/No Yes Yes Yes 
NewSubFamily Yes
No
No
Moderate
No
Rossinae No Yes No No Yes 
Sepiolinae Yes No No Moderate/No Yes 

The NewSubFamily does not fit well in the Order Sepioidea as two basic sepioid characters (eyes with secondary eyelids; funnel with lateral adductor muscles) are missing. Our first impression was that the NewSubFamily was more closely related to the Myopsida. However, many features commonly associated with the Sepioidea (absence of an interstellate connective, gills apparently without a branchial canal) and the Sepiolidae (globular sucker rings, general shape, fusion of the head and mantle in the nuchal region) convince us that its closest relationships belong within the Sepiolidae. The most convincing character is the presence of a ventral mantle adductor muscle which is common to members of the Sepiolida. The ventral mantle adductor in NewSubFamily is very weak and barely recognizable. This condition has led us to suspect that the absence of the two basic Sepioid characteristics listed above is due to loss. At present, the phylogenetic position of the NewSubFamily is guesswork since the phylogeny of the Sepiolida is in flux.

Choneteuthis tongaensis may be derived from an ancestral line leading to Sepiolina-like species and then to the remaining Heteroteuthinae. It has the heteroteuthin shield and silvery sides but lacks a tentacle organ, as does Sepiolina, but also lacks the web between arms I-III.

 

Nomenclature

A list of all nominal genera and species in the Sepiolidae 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

Naef (1921-3) divided the Sepiolidae into three subfamilies and placed Sepiolina in the Sepiolinae. We place it in the Heteroteuthinae. As Naef (1921-23) recognized, characteristics of this genus place it right between the two subfamilies. Choneteuthis which is presently not placed in any subfamily shows strong similarities to Sepiolina especially in having a large visceral photophore and ventral shield and lacking a tentacular organ. The latter feature is primarily responsible for separating Sepiolina from the remainder of the Heteroteuthinae.   Choneteuthis further confuses the boundries of the Heteroteuthinae.

A cladistic analysis has not been made on this family but one is badly needed as much disagreement exists over classification. Clarke (1988) includes this family and the Idiosepiidae in the Order Sepiolida. Fioroni (1981) includes this family in the Order Sepioloidea and includes the Idiosepiidae as a subfamily of the Sepiolidae.

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.

Fioroni, P. 1981. Die Sonderstellund der Sepioliden, ein Vergleich der Ordnungen der rezenten Cephalopoden. Zool. Jahrb., 108: 178-228.

Lu, C. C., A. Guerra, F. Palumbo and W. C. Summers. 1992. Order Sepioidea Naef, 1916. In: Sweeney, M. J., C. F. E. Roper, K. M. Mangold, M. R. Clarke and S. V. Boletzky (eds.). "Larval" and juvenile cephalopods: a manual for their identification. Smithson. Contr. Zool. No. 513: 1-282.

Naef, A. 1921/23. Cephalopoda. Fauna e Flora del Golfo di Napoli. Monograph, no. 35. English translation: A. Mercado (1972). Israel Program for Scientific Translations Ltd., IPST Cat. No. 5110/1,2.

Nesis, K. N. 1982. Abridged dey 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.

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 Heteroteuthis hawaiiensis
Location off Hawaii
Specimen Condition Live Specimen
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

Page: Tree of Life Sepiolidae Leach 1817. 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. 2007. Sepiolidae Leach 1817. Version 26 December 2007 (under construction). http://tolweb.org/Sepiolidae/19988/2007.12.26 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

Sepiolidae

Page Content

articles & notes

collections

people

Explore Other Groups

random page

  go to the Tree of Life home page
top