Squid in the family Pyroteuthidae have Photophores (small, light-producing organs) on viscera (internal organs), stalk of tentacles, and five large and ten small photophores underneath the eyes.
The squid … See more

Squid in the Pyroteuthidae family live in the mesopelagic (midwater or twilight zone) during the day. At night, they migrate to the epipelagic waters (0-200m).
There is little knowledge about the life history of th… See more

In laboratory experiments, P. giardi has been observed to produce a luminescent flash when shocked with an electrode. It is likely that the squid use these flashes as a defense against predators. Organisms with photophore… See more

P. giardi is a part of the P. giardi clade along with P. hoylei, which was originally classified as a subspecies of giardi, but was changed to species classification in 1987. P. giardi and P. hoylei are now recognized to be sister … See more