I have seen them for sale at Exotic Aquaruim in Sacramento CA, and I've collected them in HI. I read that they don't do well in typical aquariums as they live above the waterline at least part time. The one I kept went to the top corner above the water line and stayed there until it died. I tried to move it to the rocks and have several kinds of algae and nori it could have eaten, but as soon as it felt "safe" after being moved it went back to above the waterline. When I collected them, they were all above the water in wave beaten lava rocks.