Seahorses by species
Project Seahorse and the International Union for Conservation of Nature (IUCN) currently recognize 48 species of seahorse. Found mainly in coastal regions all over the world, seahorses come in many different shapes and sizes, from the big-bellied seahorse, which can reach up to 35 cm in length, to pygmy species less than 2 cm long.
Nine seahorse species are currently listed as threatened on the IUCN Red List of Threatened Species. Many more are considered data-deficient, because we do not yet have enough information about them. You can help by adding your seahorse observations and by providing species IDs for other observations.