squat lobsters sharing crinoid

I still have the two black Crinoids in my aquarium, but the purple one slowly fell apart and died. The black ones are not doing bad, still extending their arms to feed.

I was surprised last night when I glanced at one of the Crinoids to find that both of my squat lobsters were hosting in it.



Darth Maul, in the lower half of the photo, is a Galathea inflata. He prefers to cling to the rocks underneath a Crinoid. Sometimes he moves to a different Crinoid, and sometimes doesn't stand under one at all. Darth Vader, in the upper portion of the photo, is an Allogalathea elegans. He is always in a Crinoid, usually in the center or on the arms.

Squat lobsters are solitary creatures, so it's unusual to find them sharing a Crinoid. These two have not been fond of one another, either. Darth Maul has chased Darth Vader from his favorite Crinoid before. But it looks like they've made a truce. There is another Crinoid in the aquarium, exactly like this one, but they both prefer this one. They are still sharing this morning, I wonder how long this will last.