Invertebrates
See our handy guide to critters found in local homes and our Central Coast Butterfly FAQ. Browse the insects and other terrestrial arthropods we’ve identified. Check out local marine invertebrates, particularly bivalve mollusks and intertidal organisms.
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Weird Transparent Beach Thing
Hi Curator,
A couple years ago I saw this thing on the beach that was an absolute mystery. It was mostly transparent, and at first I thought it might be a piece of plastic, but when I looked at it closely, it seemed like something natural. It was a clear disc maybe about two inches across, with blue edges, and part of it kind of stood up like a mohawk hairdo. I could see tiny lines on it. Later I found more. Are these alive?
Thanks!
Curator Response
Hi Jan,
It sounds like you found Velella velella! The common name of this organism is By-the-Wind-Sailor, and it’s related to jellies and sea anemones. By-the-Wind-Sailors float on the ocean’s surface, and the structure on top acts as a little sail that catches the wind and distributes them. Sometimes the wind pushes them towards the shore and they get stranded on the beach.
A fascinating thing about them is that in a sense some are left-handed, while others are right-handed. They don’t have hands, but it has to do with the shape of the sail on top. The sail is asymmetrical, and the difference in the two configurations means that some will be sent one way by the wind, while others will be pushed in the other direction. It’s an adaptation that helps them expand their territory and protects them from all being simultaneously beached.
Like jellies, they have stingers, but the stinging parts are tiny and harmless to humans.
Paul Valentich-Scott, Curator of Malacology
