Just when we think we've seen it all, some mesmerising, sci-fi-worthy creature floats out of the depths to take our breath away. While exploring the waters off the coast of Cozumel in Mexico last month, scuba-diving instructor Frida Yolotzin filmed a rainbow tripod fish larva in all its purply, wavy wonderfulness.

Yolotzin spotted the alien-like animal on a blackwater dive, a nighttime, open-ocean exploration that involves lowering floodlights into the water to illuminate interesting nocturnal creatures. During blackwater diving, divers may be tethered to the boat as it drifts on the current or they will swim around the suspended floodlights to see what emerges from the surrounding darkness. The colourful reflection of this tripod fish drifting in the ether caught Yolotzin's eye and she trained her camera lens on the undulating life form.

"It was this extraordinarily beautiful fish swimming up and reflecting our lights in such a surreal way, being by far the most precious animal I’ve ever seen," she wrote on Instagram where she uploaded footage of the fish.

The larvae of tripod fish sport large rounded fins that are believed to help them imitate jellyfish, and avoid predators. The adults of the species live on the ocean floor anywhere from one kilometre to over six kilometres below the surface. There, they plant their three specialised, elongated fins into the sea floor and "stand", resembling a tripod (hence the name). In the larval stage, the fish may be dragged up to the surface gifting eager blackwater divers with a dazzling display.

"Probably, we will be the only humans it will ever meet," Yolotzin wrote on Instagram.

Header image: NOAA Okeanos Explorer Program, INDEX-SATAL 2010, NOAA/OER