When I moved to the coast these many years ago and started poking around in the local intertidal, I became entranced with little animals called stauromedusae. I can’t claim to have been to every intertidal site in the area, but I’ve been to several of them and I personally know the stauromedusae to occur at only two sites: Carmel Point (I’ve seen them there once) and Franklin Point (I used to see them there fairly regularly). In 2007 I went out to Franklin Point every month that had a negative low tide during daylight hours to monitor the abundance and size of the stauromedusae; heck, once I even went out in the dark armed with a headlamp and a friend who was supposed to watch my back but instead fell asleep against the cliff. The stauromedusae were easy to find that year and occurred in large numbers.
I used to be able to find the stauromedusae in one particular area on the north side of Franklin Point where the water continually swashes back and forth.
The stauromedusae would always be attached to algae, often perfectly matching the color of their substrate. I remember seeing two versions, one a reddish brown and the other a vibrant bottle green color, of the same species of Haliclystus.
In March of this year I saw a lot of small stauromedusae when I braved the afternoon winds at Franklin Point. The conditions were pretty horrid, with the water all churned up and murky so I couldn’t take any pictures, but I was happy to see my little guys because it meant they were there. I hadn’t seen them for a few years before this past spring and was beginning to doubt my search image. Huzzah for validating my gut feeling! I may have whooped and done the happy dance in my hip boots that afternoon.
Fast forward almost three months and three additional trips out to Franklin Point before I found a stauromedusa this morning. One. And it was only about 0.5 cm tall, the same size that they were in March. And it was brown, the same color as most of the algae out there. Because they live where the water is constantly moving it’s really hard to photograph them in situ. This is the best I could do:
It’s hard to appreciate from this photo just how beautiful these animals are. They are very animated, swaying in the current and although they are attached they can slowly creep over surfaces or even detach, somersault around, and re-attach. Back in the day when I used to find them frequently I brought some back to the lab to observe them more closely. I could get them to feed, but they never lasted more than about a week in captivity.
So, what exactly are stauromedusae? They are cnidarians, kin to sea anemones, hydroids, Velella velella, and jellies. Their common name is stalked jellies, and for a long time biologists considered them to be closely related to the jellies in the cnidarian class Scyphozoa. However, recent studies of the genetics of stauromedusae have caused taxonomists to elevate these creatures to their own class, the Staurozoa.
Not much is known about the ecology of Haliclystus in California, probably because they are so damn difficult to find in the field. I have one or maybe two more trips out to Franklin Point this summer before we lose the minus tides for the season; hopefully they will still be there. I’d love to get some better pictures of them to show my students this fall. Wish me luck!