A Foot-Long Seahorse

Seahorses range in size—from as small as a pine nut to as large as a banana. The largest seahorse species (pictured here) is Hippocampus abdominalis, or the big-bellied seahorse, which can reach more than a foot long (35 cm) and lives in the waters off Southern Australia and New Zealand. The smallest seahorse, Satomi's pygmy seahorse (Hippocampus satomiae), which was only described in 2008, is only half an inch long (13 mm)! It lives in the waters of Brunei, Indonesia and Malaysia.

A big-bellied seahorse

David Maynard / Guylian Seahorses of the World 2005, Courtesy of Project Seahorse