RossiinaeRichard E. Young and Michael Vecchione
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.
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
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.
A sepiolid ...
- with dorsal mantle free from head.
- without ventral mantle shield.
Figure. Left - 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.
- Interbrachial web weakly developed between arms I-III.
- Non-hectocotylized arm suckers in 2 series in most species but 4 series in at least two species.
- One or both dorsal arms of male hectocotylized; often with suckers in two or four series among other modifications.
- Tentacular clubs usually expanded.
- Keel along full length of club.
- Mantle free from head in nuchal region; nuchal cartilage present.
- Gladius fully-developed but thin posteriorly.
- Bursa copulatrix absent.
- Photohores, when present, with with small, separate oval lenses.
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 is often considered a subgenus of Rossia (Voss, 1956; Reid, 1991). We follow the classification of Nesis (1982/87).
Life HistoryRossinae females lay each egg in a capsule attached either to the substrate or another capsule to form a cluster of capsules.
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.
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.
About This Page
University of Hawaii, Honolulu, HI, USA
National Museum of Natural History, Washington, D. C. , USA
Page copyright © 2019 and
Page: Tree of Life Rossiinae 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.
- First online 30 August 2004
- Content changed 06 July 2014
Citing this page:
Young, Richard E. and Michael Vecchione. 2014. Rossiinae http://tolweb.org/Rossiinae/20023/2014.07.06 in The Tree of Life Web Project, http://tolweb.org/. Version 06 July 2014 (under construction).