noc·ti·lu·ca 
(nŏk′tə-lkə)
(nŏk′tə-lkə)n.
Any of various bioluminescent dinoflagellates of the genus Noctiluca that when grouped in large numbers make the sea phosphorescent.
[New Latin Noctilūca, genus name, from Latin noctilūca, lantern, moon : nocti-, nocti- + lūcēre, to shine; see leuk- in the Appendix of Indo-European roots.]