The Japanese pygmy seahorse, Hippocampus sp, (known locally as 日本のピグミータツノオトシゴ or Japapigu) is an, as yet, undescribed species of true pygmy seahorse found, as the name suggests, in Japan. They appear to be closely related to Coleman’s, Pontoh’s and Severn’s species, and like these other species, are not found living in close association with a specific host such as a gorgonian or soft coral.
The species is characterised, and distinguished from the other free-living pygmies, by a reticulate pattern of white lattice over the body, which often has a black spot within it. The body colouration is brown, beige, to pink and whitish.
They inhabit subtropical and temperate reefs from southern to the central west of Japan. The Izu islands of Miyake and Hachijo are good locations to find these elusive seahorses, as well as Kushimoto and Sagami Bay. I saw many in the 8-15 metre range in protected areas, where they were living amongst the algal turf and small hydroids.
Given that they are yet to receive a scientific name, it is unsurprising that very little is known about their biology or conservation. This is true of all the free-living pygmy seahorses, which are yet to receive a research focus. My work on the gorgonian-associated pygmy seahorses is the only research on these species’ biology yet to be carried out.
You can see some of my Japanese pygmy seahorses by following this link.