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 from the underlying glands. 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.

Figure. Left - Ventral view of H. hawaiiensis with the ventral mantle removed, female, Hawaiian waters. Middle - Close-up view of the same photophore. Left - See-through side view of H. hawaiiensis showing relationship between the ink sac, which surrounds the back of the photophore, the photophore and the ventral mantle shield which may act as a diffuser of the bioluminescence. Photographs by R. Young; drawing modified from Young (1977).

Brief diagnosis:

A heteroteuthin with ...

• ventral mantle shield confined to anterior half of mantle.
• fins attached posteriorly on mantle.