It’s not quite as good as a fingerprint, but individual seahorses can usually be told apart by their coronets (the top of their head that almost looks like a crown).
You may know that it’s the male seahorse who becomes pregnant. But did you know their eyes move independently? There are times I think that would be an advantage, but it’d probably just confuse me.
There are about 35 species of seahorses. In size they range from ¼ inch to a foot. Seahorse are at threatened status.