This alien-like jellyfish is not a jellyfish at all

The Portuguese man o' war is an alien-like blue floating jellyfish that travels across the Atlantic. But its looks are not the most exciting thing about it: it is not a jellyfish or an animal, for that matter.

The strange creature has jumped to the headlines this winter and spring because it reached Floridian shores where it was never seen before, sparking the curiosity of residents and media.

However, the Portuguese man o' war is relatively standard across Atlantic shores, where local authorities issue yearly warnings about its presence in winter and spring.

It looks like a floating jellyfish: it has a round, bubble-like seal on top and long blue tentacles that sink underwater. Still, the creature is actually a colony of identical individuals.

Colonial organisms are creatures composed of two or more multicellular individuals that cooperate for survival, living closely or attached to each other.

Researchers have identified seven individuals in the Portuguese man o' war. The most prominent one is the bladder, filled with gas, which guarantees mobility through floating.

Each creature's parts are responsible for different functions, like reproduction, digestion, or hunting. It uses a potent venom to paralyze and kill small fish.

According to experts from the National Ocean Service cited by The Bradenton Herald, the colony's venom is dangerous for humans but not deadly. Still, viewers should avoid touching it.

The Portuguese man o' war is not alone. Similar organisms exist all over the seas, including the Pacific Portuguese man o' war, which is not venomous.

Another alien-like blue creature, Vellela, floats in the Pacific Ocean. It looks like a tentacle-less jellyfish, but unlike the Portuguese man o' war, it is harmless.

According to The Guardian, it covers Californian shores yearly, so locals commonly call it a "blue tie" and step over their transparent bodies while walking on the beach.

Julia Parrish, a marine biologist at the University of Washington, told the newspaper that Vellela typically travels down the coast of California to Central America, then shoots out past Hawaii to Japan.

Like the Portuguese man o' war's, their movement depends on winds and currents as they float through the ocean. The Guardian said that is also why they are not widely studied.

Scientists understand the life stages and reproduction ─through a single embryo─ of these creatures, but they are hard to keep in tanks for studying due to how they live (on the ocean surface).

Still, other smaller deep-sea creatures also function as colonies. The Cercariae, a ball of parasitic worms, is an example. According to Earth.com, it is the attachment of two different types of worms.

Another example is Marrus Orthocanna, a flute-like creature that is a colony of two organisms of different classes: polyps and medusae.

Photo: Wikimedia Commons / Public Domain