Seahorses and seadragons

Many people are unaware that seahorses and seadragons are in fact fish. They have evolved some interesting adaptations to life in the sea. The combination of a horse-like snout (for sneaking up on small crustaceans), bony plates (to protect them against predators), and in the case of seahorses, a prehensile tail that allows them to cling to seagrasses, corals, and other holdfasts in ocean currents, has enabled these slow-swimming animals to survive for millions of years.

There are 46 recognised species of seahorses. Given their superior camouflage and the subtle differences between some species, taxonomists have long struggled on delineating and identifying them based on appearance alone. The rise of genomics and other molecular techniques will hopefully shed light on this matter and eventually provide a much clearer picture.

The seadragons consist of only three recognized species, the Common seadragon (Phyllopteryx taeniolatus), the Leafy seadragon (Phycodurus eques) and the newly described Ruby seadragon (Phyllopteryx dewysea). They are more mobile than seahorses and tend to orient at a more horizontal angle than their cousins. Learn more about seadragons here.

Check out the profiles of the species we currently recognize below (Lourie et al, 2016).

*Note: Currently, there are 46 recognised species of seahorse- four newly described species (H. haema, H. japapigu, H. nalu and H. waleananus) have not yet been evaluated on the IUCN Red List.

IUCN Red List key

EX = Extinct 
EW = Extinct in the Wild 
CR = Critically Endangered 
EN = Endangered 
VU = Vulnerable 
NT = Near Threatened 
LC = Least Concern 
DD = Data Deficient 
NE = Not Evaluated

(Click here for a full explanation of IUCN Red List categories.)

A note on ‘Data Deficient’ species: Species that are assessed as ‘Data Deficient’ are deemed to have insufficient information known about them to carry out a proper conservation assessment. Although such species are not assessed as threatened, we may find out that they in fact are, once enough data is obtained.