Hippocampus bargibanti

Bargibant's pygmy seahorse Strategy: background matching taken to the extreme. At most about 2.4 cm long, this seahorse lives only on sea fans of the genus Muricella, and its body is covered in knobby bumps that match the color and shape of its host's polyps. One form is pale gray or purple with pink or red bumps, like the pair pictured here on a pink fan; the other is yellow with orange bumps. It went unnoticed until a sea fan had been collected and the seahorses were spotted on it. It lives on reefs from Indonesia and Japan to northern Australia and Vanuatu. Ask a dive guide to point one out, because spotting one unaided is close to hopeless.