Are they ghosts? Phantoms? Nope ... just deep-sea creatures blowing our minds, as usual! This mesmerising video, captured by the crew of the manned submersible JAGO during a dive near Crimea, is truly worthy of a double-take. It's hard to wrap your mind around at first, but what you're seeing is field of comb jellies (jellyfish doppelgängers in the phylum Ctenophora) as it moves in and out of JAGO's light beams.

Unlike their jellyfish relatives, ctenophores (also known as 'sea gooseberries,' 'sea walnuts' and 'Venus's girdles') are voracious predators – some of which can slurp up ten times their weight in food per day! They don't use stinging cells to catch their prey, but rather rely on sticky, adhesive cells called 'colloblasts,' which typically sit along their tentilla ('little tentacles' used for hunting). As the jellies move out of JAGO's range and disappear seamlessly into the blackness, it's easy to imagine how unsuspecting prey might wind up in their sticky grasp.  

The dive was part of EU-Project HYPOX, an long-term initiative that aims to better understand the dynamics and drivers of oxygen depletion throughout the world's oceans. We'll certainly be keeping our eyes on JAGO from now on!

Top header image:Daniel Ashton/Flickr