After our first ever get wrecked trip last month one of our guests; Allen said ”The night dive on Thistlegorm was my best night dive ever…what are those fish that glow in the dark?” Well Allen as promised; The Flashlight Fish.
So called because of its glowing panel beneath its eyes which is called a photophore; these little critters tend to dwell at depth, heading to the surface at night to feed on the plankton which is drawn to the moonlight. Mistaking the glowing fish for moonlight, their favourite plankton snack or tiny crustaceans are lured in close for dinner. The photophore is actually a collection of bio-luminescent bacteria which live within the bean shaped luminous organ of the fish.
One of the very few non-deep-sea fish with such a bright light force they use their talents in a variety of ways and can even roll the panel away to theoretically turn off the light! They use their on and off light source as a fishy morse code to communicate with one another, sharing vital information on the presence of food or danger. It also may be used as a cunning way to disorientate their predators, by blinking a few times and then shutting off and swimming away fast they lure the enemy to the place they have just vacated.
In some areas of the world their great numbers by reefs have led skippers to use their lights as a method of navigating through the reef, luckily here we still rely on technology. Join an overnight get wrecked trip to catch a glimpse of this bright little fish.