HeteroteuthisRichard E. Young, Clyde F. E. Roper, and Katharina M. Mangold (1922-2003)
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Species of Heteroteuthis are the most oceanic members of the subfamily. They are capable of producing brilliant luminescence from their bacterial photophore or secreting luminescent clouds, in a variety of forms, from it. Their large visceral photophore is seen in the left photograph below with the mantle cut open; a closer view is seen to the immediate right. The two large pores on the photophore surface enable the luminescent material to be extruded. The heavy covering of iridophores that provide the variety of colors seen in the photographs appear to act as a color filter and shutter for the bioluminescence. Other members of the subfamily presumably have similar luminescent capabilities but they have not been observed.
A heteroteuthin ...
- with mantle free from head dorsally.
- with greatly enlarged suckers in males on arms III only.
- Right arms I and II hectocotylized in males (see illustrations): arm bases fused with area of fusion holding a single large gland; right arm II broadened proximally and bordered by glands.
- Arms III in males with two or three greatly enlarged suckers.
- Arms I and II in females with bare tips.
- Funnel locking-apparatus with deep, curved groove.
- Dorsal mantle free from head; nuchal cartilage present.
- Ventral mantle shield confined to anterior half of mantle.
- Posterior lobes rounded.
Three species are presently recognized in the genus, H. dispar (type species, type locality - Mediterranean Sea), H. hawaiiensis (type locality - off the Hawaiian Islands), and H. serventyi (type locality- off S. E. Australia). A fourth species H. atlantis was described by Voss (1955) from off Cuba in the Caribbean Sea but was synonymized by Nesis (1982/87) with H. dispar. A subspecies of H. hawaiiensis has been described, H. (hawaiiensis) dagamensis (type locality - off South Africa). The status of the latter is uncertain. H. dispar and H. hawaiiensis are very similar but specimens have never been directly compared. As a result, reliable characters to separate them are unknown.
H. dispar and H. hawaiiensis differ greatly from H. serventyi in the male modifications to the third arms. In H. serventyi the greatly enlarged suckers lie in the dorsal series of the arms and each alternates with a much smaller sucker in the ventral series (see drawing above). In H. dispar and H. hawaiiensis a greatly enlarged sucker occurs in the dorsal and ventral series of each arm III.
Circumglobal in tropical to warm temperate oceans.
During the day in Hawaiian waters, H. hawaiiensis less than 17; mm ML were taken mostly between depths of 250 and 350 m; squid larger than 17 mm ML were taken at greater depths of 375-650. During the night squid less than 17 mm ML were mostly taken between depths of 150 and 200 m; larger squid were taken between depths of 110 and 550 m. Males and females mature around 15-16 mm ML.
Figure. Chart of the vertical distribution of H. hawaiiensis from Hawaiian waters, taken with both opening/closing and open trawls. Large blue dots - Night captures. Large yellow dots - Day capture. Small dots - Presumed contaminents from deep open tows. Dots represent the modal depth of the trawl regardless of trawl type. Bars with dots - Trawl fishing-range of open/closing trawls. Chart modified from Young (1977).
As far as is known, sepiolids lay their eggs on the ocean floor. Species of Heteroteuthis are the most oceanic members of the family. Nevertheless, evidence suggests that they also spawn on the ocean floor at moderate depths. Nesis (1993) found them, although broadly distributed in the open ocean, more common near seamounts and submarine ridges. Boletzky (1978) described an embryo of H. dispar that had been collected in an open bottom trawl (Mediterranean Sea, 540 m depth) and presumably had been collected on the ocean floor. Okutani and Tsuchida (2005) reported numerous mature females of H. hawaiiensis on the ocean floor at a depth of 912 m near the Ogasawara Islands.
Figure. Video images of H. hawaiiensis on the ocean floor taken by the ROV Hyper-Dolphin operated from the R/V NATSUSHIMA of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) on the gentle slope of Kaikata Seamount (26°41.25'N, 141°02.72'E) at a depth of 912 m (Okutani and Tsuchida, 2005). Inserts on the upper left show two individuals swimming near the bottom. The larger image shows more than a dozen individuals swimming near the bottom.
Nesis, K. N. 1993. Cephalopods of seamounts and submarine ridges. In: T. Okutani, R. K. O'Dor and T. Kubodera (eds.). The Recent Advances in Cephalopod Fishery Biology. Tokai University Press. Tokyo, pp. 365-373.
Okutani, T. and S. Tsuchida. 2005. Occurrence and living habit of bathyal bobtail squid, Heteroteuthis hawaiiensis (Cephalopoda: Sepiolidae) from off the dOgasawara Islands, Japan.
BOLETZKY, S. v. 1978 -- Premières données sur le développement embryonnaire du Sépiolide pelagique Heteroteuthis (Mollusca, Cephalopoda). Haliotis, 9: 81-84.
Young, R.E. 1977. Bioluminescent countershading in midwater cephalopods. Proc. Zool. Soc. Lond., No. 38:161-190.
Richard E. Young
Dept of Oceanography
University of Hawaii
Honolulu, Hawaii 96822
Katharina M. Mangold (1922-2003)
Page copyright © 1996 Richard E. Young, , and Katharina M. Mangold (1922-2003)
Citing this page:
Young, Richard E., Roper, Clyde F. E., and Mangold (1922-2003), Katharina M. 1996. Heteroteuthis http://tolweb.org/Heteroteuthis/20030/1996.01.01 in The Tree of Life Web Project, http://tolweb.org/. Version 01 January 1996 (under construction).