A team of oceanographers watching a deep-sea rover’s camera never saw this coming: a young gulper eel performing fluid acrobatics for the lens.

The reactions caught on video from the group of scientists watching the gulper eel were priceless; at one point all of them oohed as the eel blew up like a black balloon.

“Big gulp! The Nautilus team spotted a gulper eel (Eurypharynx pelecanoides) doing just that in Papahānaumokuākea Marine National Monument,” wrote the team on the Nautilus’s website.

The gulper eel’s mouth can suddenly expand like a soap bubble to allow it to scoop up much larger prey, although the fish is thought to eat mainly small crustaceans. It’s theorized that, because of the fish’s tiny teeth, its ability