Our stalwart readers have come through with several batches of photos, so we’re good to go for about a week.
Today’s contribution comes from UC Davis math professor Abby Thompson, also a Hero of Intellectual Freedom. Abby’s captions and IDs are indented, and you can enlarge her photos by clicking on them.
In Northern California, April blew in the way March is supposed to, like a lion, with gusting winds and high surf.
The first set of creatures below have a lovely common name: by-the-wind sailors, and a mellifluous scientific name: Velella velella. Each mini-sailboat is actually a colony of hydroids. They’re blown willy-nilly across the surface of the sea, and when the winds and tides hit just right, they wash up onshore in incredible numbers. The first picture is the beach so covered with them it looked like it had snowed. The second is a closer-up picture of a cluster of them. The third and fourth show first a single “boat” floating right-side up, with the sail sticking up perpendicular to the surface, and then a few upside down, showing the tentacles which usually hang underneath. Velella velella are related to Portuguese men o’ war, but their tentacles don’t sting (much- at least not for humans).
Both Velella velella and Portuguese men o’ war have nudibranch predators, including Fiona pinnata and Glaucus atlanticus (blue dragon). The spectacular blue dragon seems to be always blue, and Fiona pinnata can take on the beautiful blue of its prey. Glaucus atlanticus concentrates the (painful) venom of the Portuguese man o’ war and reportedly is excruciatingly painful to the touch. Luckily the two really venomous species need warmer water than we have in Northern California.
Velella velella (by-the-wind sailor):
Epiactis prolifera (brooding anemone) This species broods its young on the outside of its column. The babies are the cream-colored flower-like things:
Epiactis prolifera again- in this one, the kids seem to have taken over the place, as kids are wont to do:
Nucella ostrina (Striped dogwinkle). These usually have boring grey and white strips, but every once in a while they’re this spectacular orange. Also I like the name “dogwinkle”:
Doto amyra (nudibranch):
Paradialychone ecaudata (another species of feather duster worm). These just appear as a fuzz on the bottom of the pools, until you look at them with some magnification:
Camera info: Mostly Olympus TG-7 in microscope mode, pictures taken from above the water.
Amazing diversity! Thanks for sharing.
Wow, the seashore is the best! Thank you.
Such fascinating structures. Fantastic photos.
Thanks!
Nice photos! Those Velella velella are beautiful little animals!
The technology really brings out how exquisite these creatures are – I’m always delighted by that.
Back in the old days, they’d look basically like blobs in a photo, if ever in a photo – perhaps though a meticulous drawing in a monograph…
… anyway…
Awesome pictures, as usual.
Really cool pictures! A friend and colleague of mine, the late Ellis Yochelson, was a paleontologist who once speculated that some weird, soft-bodied fossils that no one could identify were, in fact, By-the-wind Sailors. I had never heard of them. His idea was novel. Whether he was right or wrong, I do not know.
Very good! I wonder if the daughter polyps of the Brooding Anemone are buds, made by asexual reproduction.
Hi Mark,
The sexual life of anemones is pretty wild. I think it’s correct that if you break off a piece of one of these guys, it will grow into a new one. But in this species the babies on the column are from eggs self- or cross- fertilized and held internally, which are then pushed out onto the column, where they hatch into the babies you see (https://inverts.wallawalla.edu/Cnidaria/Class-Anthozoa/Subclass_Zoantharia/Order_Actiniaria/Epiactis_prolifera.html)
Cheers,
Abby
Gorgeous invertebrate photos! Thank you!
What a wonderful voyage into the tidepools, and onto the beaches littered with (ex) by-the-wind sailors — thank you!