Pygmy Seahorse

Photo: Ivan Samra · CC BY-NC

Bargibant's pygmy seahorses reach just 2 centimeters in length and are found exclusively on a single species of gorgonian fan — Muricella plectana — where their skin develops matching bumps and coloration so perfectly that they were not discovered until a gorgonian was examined in a laboratory in 1969. They spend their entire lives on a single fan, mated pairs maintaining fixed territories and sharing the daily care of eggs. Their extreme habitat specificity means the loss of even one gorgonian fan eliminates an entire population of this species.