Sthenoteuthis
Richard E. Young and Michael Vecchione
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close boxIntroduction
Members of Sthenoteuthis are the dominant ommastrephid squids in tropical waters of the world's oceans and are commonly seen at the ocean's surface at night. They range in size from ca. 100 mm ML to 650 mm ML.Brief diagnosis:
An ommastrephin with ...
- Large aggregation of subcutaneous photophores forming a dorsal photophore patch on anterodorsal region of mantle.
Characteristics
- Arms
- Arms tips in subadults not unusually attenuate; arms I with 20-30 pairs of suckers.
- Hectocotylus with pores. A fully developed pore passes through the protective membrane.
- Width of ventral protective membrane of arm III approximately equal to arm width.
- Arms tips in subadults not unusually attenuate; arms I with 20-30 pairs of suckers.
- Tentacles
- Largest club suckers with small pointed teeth and one large pointed tooth in each quadrant.
Click on an image to view larger version & data in a new window
Figure. Oral view of inner ring of largest club sucker of S. oualaniensis. Drawing from Roeleveld (1988).
- Funnel/mantle locking-apparatus
- Mantle locking-apparatus with anterior bifurcation.
- Mantle locking-apparatus with anterior bifurcation.
- Photophores
- Small subcutaneous photophores on ventral surfaces of mantle, head and arms III-IV (see photographs on Ommastrephinae page).
- Large, oval, dorsal photophore patch composed of dense aggregaton of subcutaneous photophores on mantle near anterior end.
- Luminous patch on ventral surface of each eyeball.
- Two photophores on ventral surface of intestine in paralarvae and juveniles.
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Figure. Dorsal and dorsal-oblique of the dorsal photophore patch in S. oualaniensis with various stages of concealment. Top - Photophore patch (white area) mostly visible. Middle - Photophore patch almost completely concealed by chromatophores. Typically in preserved squid, the patch is not seen due to chromatophore cover. Bottom left - Photophore patch half partially covered and half uncovered. Photographs by R. Young. Bottom right - Cleared and stained portion of the mantle showing the dorsal photophore patch and the tip of the gladius. Scale bar is 3 mm. Photograph from Kishimoto and Kohno (1992).
- Small subcutaneous photophores on ventral surfaces of mantle, head and arms III-IV (see photographs on Ommastrephinae page).
Comparison of species
| Funnel/mantle locking-apparatus fused | |
| Sthenoteuthis oualaniensis | Yes |
| Sthenoteuthis pteropus | No |
Distribution
Circumglobal in tropical and subtropical, occasionally in temperate waters. S. oualaniensis is found in Pacific and Indian Ocean waters and S. pteropus in Atlantic Ocean waters.References
Kishimoto, H. and H. Kohno. 1992. Development of the luminous organ in the purpleback flying squid, Sthenoteuthis oualaniensis, as shown by Alcian Blue stain techniques. Bull. Inst. Oceanic Res. & Develop., Tokai Univ, 13: 71-83.
Roeleveld, M. A. 1988. Generic interrelationships within the Ommastrephidae (Cephalopoda). P.277-314. In: M. R. Clarke and E. R. Trueman (eds.). The Mollusca. Vol. 12. Paleontology and Neontology of Cephalopods. Academic Press, N.Y., 355pp.
Title Illustrations
| Scientific Name | Sthenoteuthis oualaniensis |
|---|---|
| Location | 5 km off Kona, Hawaii at 19°42.2'N, 156°5'W over bottom depth of 1500m. |
| Comments | S. oualaniensis swimming just below the surface on a calm night (wind SW at 5 kts). |
| Specimen Condition | Live Specimen |
| Identified By | R. E. Young |
| View | Anterolateral |
| Copyright | © 2014 Jeffrey Milisen |
About This Page
University of Hawaii, Honolulu, HI, USA
National Museum of Natural History, Washington, D. C. , USA
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Page: Tree of Life
Sthenoteuthis .
Authored by
Richard E. Young and Michael Vecchione.
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- First online 29 November 2009
- Content changed 11 October 2015
Citing this page:
Young, Richard E. and Michael Vecchione. 2015. Sthenoteuthis . Version 11 October 2015 (under construction). http://tolweb.org/Sthenoteuthis/19946/2015.10.11 in The Tree of Life Web Project, http://tolweb.org/
