Counterillumination is a heavily studied example of bioluminescence, but photophores are not found solely on the ventral surface of the mantle. In a number of species, light organs are found on the arms and head. Some complex defense systems even have given squid the ability to squirt clouds of luminescent particles into the water. The following species specialize in alternate forms of bioluminescence.

Vampyroteuthis infernalis

Taningia danae

Heteroteuthis dispar