New Research Shows That Bioluminescence Evolved Frequently in Fish

New research shows that bioluminescence—a phenomenon in which organisms generate visible light through a chemical reaction—evolved many more times among marine fishes, and likely throughout the entire tree of life, than previously thought. In a study published in the journal PLOS ONE, scientists from the American Museum of Natural History, St. Cloud State University, and the University of Kansas reveal that bioluminescence evolved 27 times in marine ray-finned fishes—and 29 times if sharks and rays are counted. Here are some of these amazing bioluminescent fish:

This ceratioid anglerfish has a built-in fishing rod, a modified fin spine topped with a lure that pulses with bacterial light. Anglerfishes are the only animals known to light up in two ways: the genus Linophryne has glowing bacteria in the lure and their own chemicals that make light in a complex chin barbel.
Image: © J. Sparks, R. Schelly, D. Roje

The deep-sea hatchetfish, which gets its name from the distinct hatchet-like shape of its body, has light-producing organs known as photophores that run along the length of their body and point downward. Hatchetfishes use these structurally complex photophores to mimic any down-welling sunlight and disappear from predators lurking below.
Image: © J. Sparks, R. Schelly, D. Roje

Barbeled dragonfish 
This barbeled dragonfish is a small bioluminescent deep-sea fish with a long protrusion attached to its chin, known as a barbel, which is tipped with a light-producing organ called a photophore. It also has large photophores below its eyes used to illuminate prey and potentially communicate, and along the sides of its body for camouflage.
Image: © J. Sparks, R. Schelly, D. Roje

Stoplight loosejaw
A stoplight loosejaw (Malacosteus niger), which is capable of engulfing prey nearly as large as its own body. It has both red and blue/green photophores under its eyes. Its primary prey source, Euphausid shrimp, cannot detect red light. The loosejaw uses this “private” wavelength of light to illuminate and hunt the shrimp.
Image: © Christopher Martinez

Learn more about this research.