The red-lipped batfish lives on the rocky seabed of the Pacific. Because the floor is rough and spiky, it prefers not to swim along the bottom like a flounder. Instead it has evolved pectoral fins that work like legs to walk along the ocean floor. It doesn’t use its dorsal fin for swimming either; this has evolved into a spiny projection with a retractable ‘fishing rod’ beneath it, which it uses to lure small fish and shrimps. And the bright red lips? It turns out they really do perform a similar function to lipstick. The batfish uses them to help improve species recognition when looking for a mate.