Marine biologists with a National Oceanic and Atmospheric Administration expedition in the Mariana Trench encountered a luminous red-and-yellow jellyfish in April, Scientific American reports.

It is believed to be the first time a human has ever seen this species. The scientists will continue searching the extreme ocean depths through June 10.

From the NOAA video description:

This stunningly beautiful jellyfish was seen during Dive 4 of the 2016 Deepwater Exploration of the Marianas expedition on April 24, 2016, while exploring the informally named “Enigma Seamount” at a depth of ~3,700 meters.

Scientists identified this hydromedusa as belonging to the genus Crossota. Note the two sets of tentacles — short and long. At the beginning of the video, you’ll see that the long tentacles are even and extended outward and the bell is motionless. This suggests an ambush predation mode. Within the bell, the radial canals in red are connecting points for what looks like the gonads in bright yellow.

Scientists view never-before-seen glowing jellyfish in Mariana Trench ocean depths