Bargibant's pygmy seahorse

Photo: seahorses_of_the_world · © all rights reserved

One of the smallest vertebrates in the ocean, Bargibant's pygmy seahorse lives its entire adult life on a single Muricella sea fan, matching the host's colour and polyp texture so precisely that it went undiscovered until a biologist found one on a fan already collected for a museum. Each individual grips the fan with its prehensile tail and ambushes copepods drifting by in the current. Because they are sedentary and cryptic, sightings depend almost entirely on guide experience; once spotted, the same individual can often be relocated for months.