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Rossiinae Appellof, 1898

Richard E. Young and Michael Vecchione
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taxon links [up-->]Austrorossia [up-->]Rossia [up-->]Semirossia [up-->]Neorossia [down<--]Sepiolidae Interpreting the tree
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Containing group: Sepiolidae

Introduction

Members of the Rossinae are among the larger sepiolids reaching up to 10 cm ML (Reid, 1991). They are benthic and mostly occupy the outer portions of the continental shelves and upper regions of the slope. The subfamily nearly has a world wide distribution (see below) along parts of major land masses but is not know from Antarctic waters.

Brief diagnosis:

A sepiolid ...

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FigureLeft - Anterodorsal view of a Rossinae sitting on the ocean floor at 1100 m. Note the dorsal separation between head and mantle. Right - Side view of a swimming Rossinae at 1033 m, showing the ventral surface of the mantle which lacks any trace of a ventral shield. Note that the tentacle is coiled inward and not retracted into a pocket as in sepiids.

Characteristics

  1. Arms
    1. Interbrachial web weakly developed between arms I-III.
    2. Non-hectocotylized arm suckers in 2 series in most species but 4 series in at least two species.
    3. One or both dorsal arms of male hectocotylized; often with suckers in two or four series among other modifications.

  2. Tentacles
    1. Tentacular clubs usually expanded.
    2. Keel along full length of club.
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      Figure. Oral view of the tentacular club of Rossia pacifica, preserved. Photograph by R. Young.

  3. Mantle
    1. Mantle free from head in nuchal region; nuchal cartilage present.
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      Click on an image to view larger version & data in a new window

      Figure. Dorsal view of the mantle and head of Rossia macrosoma with anterior portion of mantle folded back to reveal the nuchal cartilage (blue) and anterior end of the gladius (red). Drawing modified from Naef (1921-23).

  4. Gladius
    1. Gladius fully-developed but thin posteriorly.

  5. Viscera
    1. Bursa copulatrix absent.

  6. Photophores
    1. Photohores, when present, with with small, separate oval lenses.

Comments

The following table compares the four genera.

  Arms II, III with greatly enlarged suckers Clubs expanded Club sucker series Photophores present on ink sac Functional Ink sac Anal flaps
Austrorossia* No No 25-50 No Yes Rudiment
Neorossia No Yes 6-7 No No Rudiment
Rossia No Yes 6-12 No Yes Strong
Semirossia Yes Yes 5-8 Yes Yes Strong

Austrorossia is often considered a subgenus of Rossia (Voss, 1956; Reid, 1991). We follow the classification of Nesis (1982/87).

Life History

Rossinae females lay each egg in a capsule attached either to the substrate or another capsule to form a cluster of capsules.
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Figure. Rossinae egg cluster from the same area in the Gulf of Mexico. Left - A recently laid cluster at a depth of 540m attached to the sponge, Topsentia sp. The individual capsules are approximately 1 cm in width.  Middle - An older cluster, at a depth of 550 m, with embryos close to hatching (note the eyes within the capsules), attached to an octocoral. Right - A small Rossinae, ca. 2 cm in length, photographed about the same time and place as the egg capsules and probably of the same species.

Distribution

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Figure. Distribution map of the Rossiinae (white lines). Distributions are approximate. Modified from Young, et al. (1998).

References

Reid, A. 1991. Taxonomic Review of the Australian Rossiinae (Cephalopoda: Sepiolidae), with a Description of a New Species, Neorossia leptodons, and Redescription of N. caroli (Joubin, 1902) . Bulletin of Marine Science, 49(3)(1991):748-831.

Young, R. E., M. Vecchione and D. Donovan. 1998. The evolution of coleoid cephalopods and their present biodiversity and ecology. South African Jour. Mar. Sci., 20: 393-420.

Voss, G.L. 1956. A Review of the Cephalopods of the Gulf of Mexico. Bulletin of Marine Science of the Gulf and Caribbean, 6(2):85-178.

Title Illustrations
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Scientific Name Rossia sp.
Location Off N.E. United States
View Dorsolateral
Image Use creative commons This media file is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0.
Copyright © 2004
Scientific Name Rossia glaucopis
Reference Verrill, A.E. 1880-1881.  The cephalopods of the north-eastern coast of America. Part II. The smaller cephalopods, including the "squids" and the octopi, with other allied forms.  Transactions of the Connecticut Academy of Sciences, 5(6):259-446, 33 plates.
View Dorsal
Size 23 mm ML
Scientific Name Rossia glaucopis
Reference Verrill, A.E. 1880-1881.  The cephalopods of the north-eastern coast of America. Part II. The smaller cephalopods, including the "squids" and the octopi, with other allied forms.  Transactions of the Connecticut Academy of Sciences, 5(6):259-446, 33 plates.
View Ventral
Size 31 mm ML
About This Page


University of Hawaii, Honolulu, HI, USA


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

Page: Tree of Life Rossiinae Appellof, 1898. 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. 2014. Rossiinae Appellof, 1898. Version 06 July 2014 (under construction). http://tolweb.org/Rossiinae/20023/2014.07.06 in The Tree of Life Web Project, http://tolweb.org/

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