How large are seahorses?

The length range of seahorses is quite varied. The smallest species, the dwarf seahorse (Hippocampus bargibanti), measures just over 1 inch in length. The largest species, the big-belly seahorse (Hippocampus abdominalis), can grow to be over 14 inches in length. Most species of seahorses, however, fall somewhere in between these extremes, ranging from 2 to 10 inches in length.