Sepiolina
Sepiolina petasus
Tsunemi Kubodera and Richard E. YoungIntroduction
Sepiolina petasus is known from two male specimens, one mature (holotype) and the other nearly mature (paratype). The paratype was taken in the same tow with with six Sepiolina nipponensis. The holotype was taken in an adjoining station. The new species was first recognized by its more elongate shape:![Click on an image to view larger version & data in a new window](/tree/img/magnify.gif)
![](/tree/ToLimages/s.petasusall.350a.jpg)
Figure. Of these Sepiolina specimens captured together, the S. petasus seems more slender. Photograph modified from Kubodera and Okutani, 2011.
Brief diagnosis:
A Sepiolina with ...
- a slender mantle in males (at least).
- a 3.48% difference in mtDNA COI from S. nipponensis.
Characteristics
Most morphological characteristics are similar to those of S. nipponensis as indicated by the following image:
![Click on an image to view larger version & data in a new window](/tree/img/magnify.gif)
![](/tree/ToLimages/s.petasusoral.300a.jpg)
Figure. Oral view of S. petasus, holotype. Photograph modified from Kubodera and Okutani (2011).
At present the only morphological distinctive feature of S. petasus is its slender mantle. The ratio of ML to MW in S. petasus is 58% in the holotype and 53% in the paratype; for S. nipponensis the ratio is 79-99%.
The genetic distance between S. petatsus and S. nipponensis for the mtDNA COI sequences was 3.48%. This compared to differences between S. petasus and Stoloteuthis japonica of 7.69%; between S. petasus and Heteroteuthis ryukyuensis of 7.51%; between S. petasus and Heteroteuthis hawaiiensis of 10.81% and between S. petasus and Stoloteuthis leucoptera of 9.16% (Kubodera and Okutani, 2011). Groenenberg et al. (2009) found cryptic sister species of Sepiola atlantica, that could not be separated morphologically were separated by a 3.5% minimum sequence divergence with the COI gene (Kubodera and Okutani, 2011).
Distribution
S. petasus is known only from the region of the type locality near Kume-shima Island, Okinawa Islands at 25°48'N, 126°31'E. Specimens were captured in bean trawls fishing on the sea foor at 563-565 m and 372-375 m depth.References
Kubodera, T. and T. Okutani. 2011. New additions of luminous bobtail squids to the Japanese cephalopod fauna (Sepiolida: Sepiolidae: Heteroteuthinae). Venus, 69 (3-4): 145-161.
Groenenberg, D. S. J., Goud, J., Heiji, A. D. & Gittenberger, E. 2009. Molecular phylogeny of North Sea
Sepiolinae (Cephalopoda: Sepiolidae) reveals an overlooked Sepiola species. Journal of Molluscan
Studies 75: 361–369.
Title Illustrations
![Click on an image to view larger version & data in a new window](/tree/img/magnify.gif)
About This Page
National Science Museum, Tokyo, Japan
University of Hawaii, Honolulu, HI, USA
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Sepiolina
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. Sepiolina petasus . Tsunemi Kubodera and Richard E. Young.
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- First online 04 November 2015
- Content changed 04 November 2015
Citing this page:
Kubodera, Tsunemi and Richard E. Young. 2015. Sepiolina http://tolweb.org/Sepiolina_petasus/149656/2015.11.04 in The Tree of Life Web Project, http://tolweb.org/
. Sepiolina petasus . Version 04 November 2015 (temporary).