Hippocampus japapigu is a precious new species of seahorse that was recently described from Japan. Despite its recent description, this very tiny seahorse has been documented for over a decade in the waters of Japan and was previously believed to be a variant of Pontohi’s seahorse, Hippocampus pontohi.
What this really tiny, barely half-inch pygmy seahorse lacks in size it more than make up for with an exquisite color and pattern, if your vision is good enough to see it. The Japanese pygmy seahorse clocks in at barely 16 mm but it displays a very attractive honeycomb pattern which is punctuated with a series of red spots on the tail and the occasional colored branched filaments on its back.
While you might not be able to tell the difference in the wild, in close up images the japanese pygmy seahorse is differentiated from Pontohi’s pygmy seahorse by the fine reticulated pattern over a good part of the body and face. Like other pygmy seahorses, Hippocampus japapigu only has a single gill opening which is a very unique trait and very different from the much more numerous large seahorse species. [ZooKeys]