My favourite rock in the tank is covered in purple coraline algae, orange zoos, sunflower zoos, and the gorgeous ricordia I bought when I got my new job, and which has since spread like mad.
When we originally bought the orange zoos, they came with a big (1 1/2″) brown and white striped starfish. Starfishes can spread asexually, and at this point we have well over 25 in our tank. They’re light-shy, and so you rarely see their bodies. Random legs sticking out of holes in the rock or from behind a coral are a much more common sight. Here’s a photo with Clack and a hermit crab for scale (the crab’s shell is 3/4″). And at the edge of the rock, you can see brown and white legs waving in the current.
But usually the starfish are hard to see. I came home to find out that had three legs emerging from one hole, and a fourth from another, at the front of the ricordia rock.