The tiny Bargibanti's pygmy seahorse (Hippocampus bargibanti) lives in the western central Pacific Ocean. They live on red sea fans (gorgonians), and each seahorse will spend most of it's life on a single sea fan, usually in a space of less than five feet.
These tiny seahorses are almost impossible to see as they are only about 2cm long and are well camouflaged, since they look almost exactly like the sea fans they live on.
In November of 2007 I was lucky enough to see and photograph a pygmy seahorse at Tanavula Point in the Florida Islands - a small group of islands in the Central Province of the Solomon Islands. He was found 86 feet underwater by another diver using a big magnifying glass and a small flashlight. If you look closely at the back of the seahorse's "neck" in this photo, you can see the yellow-colored light from the other diver's flashlight. I held as still as I could underwater and photographed him with a 60mm macro (close-up) lens.