ABSTRACT
The production of living light - bioluminescence, is a widespread but very unevenly distributed phenomenon among living organisms. Bioluminescence is an oxidative chemical reaction where the enzyme, known as luciferase and the substrate, known as luciferin, are synthesised by living organisms. Bioluminescence is found in both families of this rather morphologically homogenous group, the blackchins and the lanternfishes. The most common and widespread type of bioluminescence in ceratioids is due to non-culturable luminous bacteria hosted in the esca - the terminal bulbous part of the ilicium. The early appearance of some light organs in myctophid larvae could potentially be an indication of other uses of bioluminescence at low light levels, such as at night. The most common and widespread type of bioluminescence in ceratioids is due to non-culturable luminous bacteria hosted in the esca - the terminal bulbous part of the ilicium.
