For the past year I’ve had the lovely privilege of working a few days a week near Harvard University’s Natural History Museum, and during my lunch breaks I sometimes go there for a quick walk around. It’s not a huge museum, but it is packed with interesting finds. I like to go in and spend a few minutes looking more closely at just a few things.
It struck me today that I could share with you my little little finds and do a little bit of basic internet research beyond the museum signage. I visit the museum most weeks so it could be a fairly regular series of blog posts.
I was drawn to this little guy because of its almost flower-like, bright blue limbs, and also because it’s name struck me as rather poetic: Sea Swallow.
This Sea Swallow is part of the glass sea creatures exhibit that went on display fairly recently. (The sea creatures, as well as the museum’s longstanding glass flowers collection, were made by the father/son artist team Leopold and Rudolf Blaschka, commissioned by Harvard for study purposes.)
They’re sea slugs. Certainly they’re beautiful, and the beautiful name fits, but I wanted to know why they’re called Sea Swallows.
They don’t live on the sea floor (in science speak, they’re pelagic, not benthic). Rather, they live by floating upside down on the surface tension of the water, and are swept along by winds and ocean currents.
Imagine those tiny surface-skimming insects that walk across the surface of water. Sea Swallows are doing the same thing, but flipped over and underneath the surface, as if on the underside of a pane of glass. (I had no idea that was possible, and now I am really excited.) They also take gulps of air to make themselves buoyant and have a bit of their own mobility.
So I guess they’re ‘Sea Swallows’ because they’re up there, floating around at the very top limit of the ocean, kind of like birds in the sky.
Look! Look! (The bigger ones are the G. atlanticus. They’re about 3 cm long.)
They nibble at the tentacles of the toxic Portuguese Man o’ War (which look like jellyfish, but actually aren’t. They’re colonies of individual creatures called zooids that cluster together based on their ‘job’ in the colony. Sneaky.)
Sea Swallows secrete (store in their cells) the toxins from all that nibbling in their blue wavy fingers (cerata). Their stings can be even more dangerous than the Man o’ War’s, because they consume and concentrate a lot of the toxins.
Beautiful, but no touching.
(These factoids just came from Wikipedia page here.)