10. Sepioteuthis sepioidea (Caribbean Reef Squid)

9. Dosidicus gigas (Humboldt Squid)

8. Promachoteuthis sulcus (”Lolsquid”)

7. Helicocranchia sp. (Piglet Squid)

6. Histioteuthis sp. (Jewel Squid)

H. cerasina - photo by Richard E. Young (from tolweb.org)

The Jewel Squids get their name from the distinctive large integumental photophores that make it look as though they’ve been run through a Bedazzler. They are moderate sized squid with long arms and short mantles (up to 33 mm long) with very small fins at the posterior tip. They are also commonly known as Cock-eyed Squid because their eyes are different sizes—the left eye is significantly larger than the right, is semitubular (not hemispherical), bulges out of the head, and is directed vertically, pointing up toward the surface.

S. hoylei - photo by R. Young

Depending on who you ask, the family Histioteuthidae contains either one or two genera, and up to 19 species. Some researchers place three of the species in the genus Stigmatoteuthis, which is distinct from Histioteuthis by the presence of even longer arms (relative to mantle length) and paired secondary reproductive organs.

Histioteuthids are oceanic squid found world-wide at depths of around 2500 ft. They have often been observed from submarines with their arms curled up over their heads in a way that give the appearance that the arms are tied in knots.

Jewel Squid – Submarine Ride 2540 Feet, originally uploaded by hankplank.

This photo was taken at a depth of 2540 ft off the coast of Roatan. The Jewel Squid (Histioteuthis sp.) are notable for having one eye that is significantly larger than the other. For this reason they are also known as the Cock-eye Squid. When feeding at night, Jewel Squids orient themselves so that the larger eye is pointing upward, presumably to spot potential prey as it is silhouetted against the surface. Histioteuthis are moderate sized squid, with a max mantel length of about 33cm.