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Promachoteuthis megaptera Hoyle 1885

Richard E. Young and Michael Vecchione
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Containing group: Promachoteuthidae

Introduction

Promachoteuthis megaptera is known from only two specimens: the holotype, 15 mm ML captured during the Challenger Expedition in the late 19th century and a female, 52 mm ML, captured 105 years later (1980) from nearly the same locality. It is most easily distinguished from congeners by the lack of a head-mantle fusion in the nuchal region, the long arms and tentacles, and a dark band at the base of the tentacles (see arrow in title photograph).

Diagnosis

A promachoteuthid...

Characteristics

  1. Tentacles
    1. Long, thick (length >2 times ML); base appears much wider than arm III (judging from title photograph).
    2. Club with many series (number uncertain) of small suckers.
    3. Suckers with smooth inner rings.
    4. Large arm suckers approximately four times the diameter of large club suckers (see drawings with same magnification on the right).
    5. Dark pigment band near tentacle base present (see title photograph above and drawing of head below).
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      Click on an image to view larger version & data in a new window

      Figure. Comparison of a club sucker (left) and an arm sucker (right) of P. megaptera, 52 mm ML. Drawing from Okutani (1983).

  2. Arms
    1. Arms long (60-90% of ML)
    2. Suckers with smooth inner rings and pegs on outer rings.

  3. Head and funnel
    1. Eyes small (1.6 mm in 15 mm ML squid).
    2. Eyes embedded in head and connected to exterior by narrow canal (drawing below).
    3. Mantle free from head in nuchal region; nuchal cartilage present (drawing below).
      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. Left - Lateral view of the head showing the eye canal of P. megaptera, 52 mm ML. Right - Dorsal view of the nuchal cartilage of P. megaptera. Drawings from Okutani (1983).

Comments

This description, except for comments reflecting uncertainty, is taken from Okutani (1983). Additional details of the description can be found here.

Life History

The larger squid was a female with small nidamental glands and an immature ovary.

Distribution

This species is known from two localities, both near Japan: 34°37' N, 140°32' E (type locality; 0-3690 m) and 31°00' N, 147°00' E (2750 m).

References

Okutani, T. 1983. Rare and interesting squid from Japan. VIII. Rediscovery of Promachoteuthis megaptera Hoyle, 1885 (Oegopsida: Promachoteuthidae). Venus 42: 241-247.

Roper, C. F. E. and R. E. Young (1968). The family Promachoteuthidae (Cephalopoda: Oegopsida). I. A re-evaluation of its systematic position based on new material from Antarctic and adjacent waters. Ant. Res. Ser., 11: 203-214.

Title Illustrations
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Scientific Name Promachoteuthis megaptera
Comments Arrow points to the unusual pigment band at the base of the tentacle.
Reference Okutani, T. 1983. Rare and interesting squid from Japan. VIII. Rediscovery of Promachoteuthis megaptera Hoyle, 1885 (Oegopsida: Promachoteuthidae). Venus 42:241-247. with permission.
Sex Female
Life Cycle Stage Immature
Size 52 mm ML
Scientific Name Promachoteuthis megaptera
Reference redrawn type illustration from Roper, C. F. E. and R. E. Young (1968). The family Promachoteuthidae (Cephalopoda: Oegopsida). I. A re-evaluation of its systematic position based on new material from Antarctic and adjacent waters. Ant. Res. Ser., 11: 203-214.
View ventral
Type holotype
Image Use creative commons This media file is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0.
Copyright © 1968
About This Page


University of Hawaii, Honolulu, HI, USA


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

Page: Tree of Life Promachoteuthis megaptera Hoyle 1885. 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. 2003. Promachoteuthis megaptera Hoyle 1885. Version 01 January 2003. http://tolweb.org/Promachoteuthis_megaptera/19528/2003.01.01 in The Tree of Life Web Project, http://tolweb.org/

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