The Vivacious Velella velella

By Maureen Wyer

I have been beachcombing for about six years and am mainly interested in sea glass. However, I will never forget the day I found my first blue, jellyfish type, alien-looking species at one of my favorite local beaches in Sydney Harbour, Australia.

I was intrigued, and at first glance it reminded me of an upside-down spinning-top toy. On closer inspection, I was blown away by the intricate details of this tiny marine specimen, best described as a blue disc with a sail-like feature on top.

When I say tiny, it was minuscule, only the size of my fingernail. I would have easily missed it except I spend a lot of my time down low on the sand photographing my sea glass finds. I was keen to photograph this new creature and show off its most amazing features, especially the deep blue coloring of the base which has grooves on it resembling a fingerprint.

Over time, I have gone on to find many more, often in groups. It is quite a special sight to see so many. Some have their ink coloring leaking out onto the sand, and I have also found some clear ones that have dried up and lost their blue pigmentation altogether yet remain so stunning and delicate.

I have since researched and discovered that they are not technically a jellyfish, though they are close relatives. Their scientific name is Velella velella. Due to their sail-like feature they are also known as by-the-wind sailors.

Velella velella can be found in Australian waters as well as warmer waters worldwide, especially in the Pacific Ocean. Due to tides and winds, they drift onto shore, where they eventually disintegrate.

They live and float near the surface of the ocean with their short tentacles hanging below the water. They have a series of sealed air/gas chambers to help them stay afloat, and their movement is powered by the wind hitting their “sail.” This sail has a slight S-shape to prevent falling over in strong winds—such a clever design by nature.

They have stinging tentacles on their underside around their mouth to help them catch and eat plankton and fish eggs. Unlike other jellyfish with stinging tentacles, Velella velella are so small they should not harm humans—however, it’s probably best not to touch your eyes or face after handling them. They are preyed on by sea slugs and sea snails. Apparently they can grow up to seven centimeters (about three inches) in size, but I have only come across specimens of one to two centimeters.

Velella velella are usually deep blue in color, and interestingly most sea creatures that live on the surface of the water have similar blue pigmentation. The blue bottle jellyfish and the Janthina janthina (violet sea snail) are two species that I also love to find and photograph, and they also wash up on my local beaches. It seems that this blue pigmentation may serve different purposes for different organisms, most likely a combination of camouflage and protection from the sun’s rays.

One curious fact I found was that the little clear sail is made of the same material and tough substance that gives structure to crabs and lobsters. And maybe the most interesting fact I found was that Velella velella can be spotted floating in the water at night, glowing bright light blue due to their own bioluminescence. That is a sight I would love to see.

As a frequent beachcomber I may not come across Velella velella often, but when I do, it’s a real treat to capture their beauty through photos. I am still amused and amazed by their incredible and beautiful features. So I have fondly named them the vivacious Velella velella.

All photos courtesy of Maureen Wyer except as marked.

This article appeared in Beachcombing Magazine Volume 46 the January/February 2025 issue.