I have been collecting a photo of coral patterns for many years. After all, as you know, there are no two absolutely identical corals. Even the neighboring fragments will necessarily differ from each other. Texture, color, shape ...
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I look at different sites, trying to find the most interesting. And while I regularly see different tiny sea creatures. Of course I also photograph them. However, most often the coral itself is lost to the second plan. At least because with this macro shooting, the depth of field is tiny, and everything does not fit into it.
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But there is an exception to this rule. Most often these are gobi fish, or their closest relatives. They are tiny and on a scale very fit coral pattern. In addition, the fish most often inscribes itself into this pattern, so that it is convenient. It turns out that it almost becomes a part of it. Of course, for her it's a way to fight for survival - mimicry.
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But for me it's luck. After all, while it is perfectly fit in the area of sharpness with the coral itself. Yes, and complements his drawing. The photo does not lose graphics, but it acquires an additional accent. Fortunately gobi is not the rarest fish. They exist in almost all the tropical seas and on many coral reefs. Another thing is that it is not so easy to find it.
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But a bit of training, and the eyes themselves find a tiny stroke on the background of the geometry of the coral. Further, the main thing is not to scare it with your appearance and the camera. After all, you need to shoot from a distance of several centimeters.
True fish usually leave if not close. And if you're lucky, you can make several different plans at a time, so that later you can choose from it.

The Caribbean Sea, Bonaire Island.