Are lanternfish real?
Fish you are referring to by description "fish with a hanging lantern over its head", are not lanternfish. Fish with "lantern" bait above head are members of group of fish named anglerfish (Lophiiformes). 

You can find more information about them here: https://en.wikipedia.org/wiki/Anglerfish

Lanternfishes or myctophids are smaller fish that use bioluminecence for communication during mating season. 

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