Hi. I agree. His analogy is correct. And, we love the way their color changes depending on where they are in the tank. I never thought about a royal gramma, I do like their looks, but we've ordered a long nose hawkfish. We lost one and miss it. Hawkfish, flit from one rock to another or sit on the plant leaves. They're really entertaining also. And, we love our little scooter blenny. Talk about cute!