The ribbons of purple and blue tentacles coiling in the video above look like they belong to some kind of alien lifeform. But this sea creature can actually be found floating on the surface of our oceans.

Physalia, also referred to as the Portuguese Man-of-War, is a kind of plankton—soft-bodied animals that drift in both salt and fresh waters. Plankton encompass aquatic creatures large and small, from jellyfish to marine viruses, and hold an important position in the food chain of marine wildlife. Here is a closer look at three of the most majestic drifters in the ocean.

The Portuguese Man-of-War

One section of a Physalia’s body acts as a floatation device filled with gas called a pneumatophore. [Photo: NOAA/Public Domain]

The Portuguese Man-of-War is a complex creature known as a siphonophore, which is an animal comprising of a colony of smaller organisms that work together. Physalia have four polyps, each performing a specific function. In the video, the twitching tentacles make up one polyp. The tendrils (which can dip down to 165 feet below the surface) are covered with venomous nematocysts that paralyze and kill entangled small fish and sea creatures—the stings also harmful enough to leave welts on human skin. The muscles in the tentacles slowly pull up captured prey to the digestive organisms of the colony.

The uppermost polyp is a gas-filled chamber or bladder called a pneumatophore that allows Physalia to drift with the current. Sitting atop the ocean’s surface, the Physalia looks like the sails of the 18th-century Portuguese warships that they get their nickname from. You can find them floating in groups of thousands in warm ocean waters.  

Sea Angels

These mesmerizing pink sea angels, or Clione limacina, have been studied extensively for their graceful swimming behavior. These naked sea slugs have wing-like appendages that gently flutter deep in the cold Subarctic and North Atlantic Oceans. Sea angels can paddle their wings at speeds up to 100 millimeters per second and their bodies average around two millimeters in length.

But don’t be fooled by their delicate appearance. Sea angels are vicious predators. They are equipped with six sharp buccal cones, or tentacles, that are concealed in the face. When unsuspecting prey drift by, sea angels lash out their buccal cones and wrestle with its dinner until it’s eaten. Sea angels have also been seen ambushing prey together. 

Lobed Comb Jellies

The lobed comb jelly, a kind of Ctenophore, are oval-shaped animals lined with eight rows of flickering cilia. These six-inch long, bioluminescent creatures emit light from their translucent bodies, giving off a mystical glow. The cilia pulse against the water as their mucous-covered bodies glide.

As the footage from the Monterey Bay Aquarium zooms in on the cilia, the rows look like flickering neon lights of a rainbow ride at a carnival. This shimmering effect occurs because the cilia diffracts light. Often confused with jellyfish, lobed comb jellies don’t sting, but instead bite off chunks of prey nearly half their size—holding their food in their pink expandable guts.

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