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Abraliopsis (Micrabralia)

Richard E. Young
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taxon links [up-->]Abraliopsis gilchristi [up-->]Abraliopsis sp. E [up-->]Abraliopsis lineata [up-->]Abraliopsis sp. NC1 [up-->]Abraliopsis sp. NC2 [down<--]Abraliopsis Interpreting the tree
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Containing group: Abraliopsis


The subgenus Micrabralia is presently a catch-basket for species that don't fit into the other two subgenera. The only unifying characters are (1) the presence of complex, integumental photophores in linear series on the head (in which it differs from A. (Abraliopsis) and A. (Boreabraliopsis) but shares with A. (Pfefferiteuthis), and (2) the absence of all the male modifications of both arms IV of A. (Pfefferiteuthis). A. (Micrabralia) gilchristi has strong similarities in character 1 with species of A. (Abraliopsis) and in character 2 with species of  A. (Pfefferiteuthis).


Table. This table compares major features of the five species of the subgenus.

  A. gilchristi
A. lineata
Abraliopsis sp. NC1
Abraliopsis sp. E
Abraliopsis sp. NC2
Club keel
  low, short low, short
Carpal flap
 low, short  absent
Size of large ventral:dorsal club hooks
 >3:1 <1.5:1 
 2.5:1  3:1
Arms I and/or II in males with tubercules
Yes, mostly arm II
Yes, mostly arm I
Yes, only (?) arm I
 No No
Distal third to half of arms IV bare 
No (?)
 No No
Length of arms IV
43-62% of ML
 50-60% of ML
75-91 (x̅ =81.5, n=12)
 81% of ML  72-92 -(x̅ =87.1, n=7)
No. hooks, arms IV
 10-13  8-14 (x̅=10.6, n=14)
 18,24 20-29 (x̅ =23.4, n=10)
Spermatangia receptacles
Dorsal collar, Stellate pouch, Nuchal cartilage
Dorsal collar , Stellate pouch
 ? Dorsal collar , Stellate pouch 
No. of ventral head photophore series
 3  3  3  3
Photophores in Medial Head Sector
None to few
 Many throughout
 Many throughout  None  Many throughout
A. gilchristi differs from other members of the subgenus in many additional characters than those listed here and should be in a separate subgenus. However, we suspect that many more species of Abraliopsis are waiting to be discovered suggesting that a phylogenetic revision of the genus is premature.
Title Illustrations
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Scientific Name Abraliopsis sp. E
Location Central Equatorial Pacific at 715'N, 14954'W
Specimen Condition Preserved
Sex Male
Life Cycle Stage Mature
View Ventral
Size 21 mm ML
Collector Thomas A. Clarke
Image Use creative commons This media file is licensed under the Creative Commons Attribution License - Version 3.0.
Copyright ©
About This Page

University of Hawaii, Honolulu, HI, USA

Correspondence regarding this page should be directed to Richard E. Young at

Page: Tree of Life Abraliopsis (Micrabralia). 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. 2016. Abraliopsis (Micrabralia). Version 29 August 2016 (under construction). http://tolweb.org/Abraliopsis_%28Micrabralia%29/149533/2016.08.29 in The Tree of Life Web Project, http://tolweb.org/

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