These eels glow green. But why?
New research by a team of Baruch scientists reports the discovery of the first fluorescent protein from a moray eel. The breakthrough was described in a paper published in Frontiers in Marine Science co-authored by WSAS Professors David Gruber and Jean Gaffney (Natural Sciences), along with two CUNY Graduate Center students from Professor Gaffney’s lab at Baruch, Andrew Guarnaccia and Sara Krivoshik.
“This study raises intrigue as to what role the glowing molecule plays in these mysterious marine eels,” Professor Gruber said. “It may be related to attracting each other for full moon mating events.”

The discovery also has implications for pediatric healthcare. “This eel protein has the potential to be used as a diagnostic tool to quickly test for bilirubin levels for childhood jaundice,” Gruber said. “Being able to measure bilirubin from a single drop of blood would be very beneficial, as drawing enough blood from newborns presents challenges.” This potential application follows up on a patent previously awarded to CUNY. That patent, which was related to this research and childhood jaundice, was awarded to Professors Gruber, Gaffney and Vincent Pieribone in 2018.
Professors Gruber and Gaffney both hold appointments at The Graduate Center as well as at Baruch. Professor Gruber is a marine biologist and Presidential Professor of Biology and Environmental Sciences at Baruch. Professor Gaffney’s field is chemistry. She was awarded a National Science Foundation CAREER award that partially funded the research. The two scientists have been collaborating on this topic for several years.
A recent story published by The Graduate Center, CUNY, focuses on the contributions of the PhD students to the research.
Their recent study includes work by John Sparks, curator of ichthyology at The American Museum of Natural History and professor of Biology at The Graduate Center. Gruber and Sparks created the American Museum of Natural History exhibition “Creatures of Light” in 2011, which broke AMNH attendance records for temporary exhibits. The show returned to AMNH last summer. The eel narrative was also featured prominently in the 1 hour NOVA documentary Creatures of Light.
The team also discovered the mechanisms of biofluorescence in sharks in 2019, which was covered by The New York Times, PBS, and other outlets. Gruber’s discovery in 2014 of widespread biofluorescence in over 180 species of fish also received widespread media attention.