Yeah, it's wild they do actually have large "photophores" at the ends of their arms. More info here:

https://www.livescience.com/animals/squids/elusive-octopus-squid-with-worlds-largest-biological-lights-attacks-camera-in-striking-new-video

https://en.wikipedia.org/wiki/Taningia_danae

Taningia danae, the Dana octopus squid, is a species of squid in the family Octopoteuthidae, the octopus squids. It is one of the largest known squid species, and it has one of the largest photophores (light organs) known in any organism.