Denise’s pygmy seahorse or yellow pygmy seahorse, also called Hippophippocampus denise, is a seahorse native to the western Pacific. The Denise’s pygmy seahorse is a small fish that grows to a maximum length of 2.4 cm, making it one of the smallest seahorses. These seahorses will use camouflage and changing color to match that of the surrounding gorgonians. It grubs on small crustaceans and other zooplankton.