Video of a blue-green nocturnal glow moving under the surface of the sea off Puerto Rico has gone viral on TikTok in recent days.

The glow was recorded by fishermen who were in the area, without, however, detecting any human activity, such as nighttime underwater filming by some documentary crew (see the original video without the commentary at 1.06).

As users are not sure what exactly it is, they have called the glow an “alien mermaid”.

@the_paranormal_chic USO-Alien Captured in Puerto Rico, you tell me! #USO #ufo #ufocommunity #ufotwitter #aliensighting #alien #aliens #underwater #unexplained #theparanormalchic #paranormal #paranormalinvestigator #ufotiktok #ocean #puertorico🇵🇷 #worldwide #groundbreaking #fyp ♬ original sound – The Paranormal Chic 🖤

In fact, some claimed to have seen a figure whose upper part looked like a man with long hair and whose lower part looked like a fish.

Others, more… pedantic, simply explained that it was nothing more than a natural formation or an optical illusion created by the interaction of light and water.

In any case, the footage is impressive.