The Firefly Squid is a bioluminescent squid growing to a length of only three inches. The squid is equipped with special light-producing organs called photophores that emit a deep blue light. 

Large photophores can be found on the tips of the tentacles as well as around the eyes. Thousands of tiny photophores can be found throughout the squid’s body, giving it the ability to emit light along its entire form. In the Toyama Bay, in the central Japan Sea, the squid are found in fantastic abundance. (Source)