Fluorescent Friday – Reef fish edition

Coral reefs are one of the most richly fluorescent ecosystems on the planet. When it comes to fluorescence, most of us reef aquarists tend to think of corals first, but many of the tropical reef fish in your tanks right now have fluorescent properties of their own.

The last few years have unearthed a flurry of discoveries regarding fluorescent reef fish, beginning with red fluorescent fish in the Red Sea and more recently with ‘biofluorescence’ discovered to be widespread in marine fish. We’ve tried our hand at photographing fluorescence in wild corals before, but the past few weeks we dabbled in photographing fluorescence in some of our favorite marine fish.

red-fluo-cleaner-wrasse-1 — The red fluorescence of this cleaner wrasse is one of the most surprising examples of fluorescent reef fish, considering that it is simply black and blue under regular lighting

Our fluorescent investigation of reef fish late one night at Bali Aquarium yielded a number of unexpected surprises, with many familiar fishes being successfully photographed in completely unfamiliar spectrum. We already knew that flasher and fairy wrasses fluoresced a nice deep red, and the coveted Red Rhinopias fluoresced a deep red to compliment its daylight coloration.

What was unexpected is that we found a chinstrap jawfish fluorescing a brilliant green, and so did the illustrious borbonius anthias. The orange coloration of the Tomiyamichthys goby and a dragonface pipefish is especially attractive, but the biggest surprise came from the cleaner wrasse. Labroides dimidiatus, a fish which is black and blue in regular lighting fluoresced a deep red under fluorescent lighting! However this wasn’t true for the related bicolor cleaner wrasse which we also sampled.

The natural, human reaction to the fluorescence of reef fish is to ask why this phenomenon is so widespread across both bony fish, sharks & rays, and even reptiles. Some proteins are just coincidentally fluorescent, but in the case of the Rhinopias, it makes sense that it would fluoresce red just as the macroalgae that it mimics also fluoresces red. For our part we’re just happy to enjoy this natural occurrence in both our reef corals and fish and we hope you’ll agree it makes for some stunning natural imagery.

OLYMPUS DIGITAL CAMERA — A fluorescent Odontanthias borbonius

dragonface-pipefish-fluo-1 — This dragonface pipefish, Corythoichthys sp., glows with fluorescent orange lines on its head and body

orange-tomi-goby-1 — This Tomiyamichthys goby is subtle shades of brown under white light but glows a brilliant orange under fluorescent lighting

Jake Adams

Jake Adams has been an avid marine aquarist since the mid 90s and has worked in the retail side of the marine aquarium trade for more than ten years. He has a bachelor’s degree in Marine Science and has been the managing editor of ReefBuilders.com since 2008. Jake is interested in every facet of the marine aquarium hobby from the concepts to the technology, rare fish to exotic corals, and his interests are well documented through a very prolific career of speaking to reef clubs and marine aquarium events, and writing articles for aquarium publications across the globe. His primary interest is in corals which Jake pursues in the aquarium hobby as well as diving the coral reefs of the world.