Woodcut of a "sea horse" from Des Monstres et prodiges by Ambroise Par矇, 1573. Des Monstres is filled with unsubstantiated accounts of sea devils, marine sows, and monstrous animals with human faces. With its extensive discussion of reproduction and illustrations of birth defects, the book invited accusations of pornography. Seahorse is the title given to 54 species of marine fish in the genus Hippocampus. Hippocampus comes from the Ancient Greek hippos meaning "horse" and kampos meaning "sea monster". They are named for their equine appearance. Although they are bony fish, they do not have scales but rather thin skin stretched over a series of bony plates, which are arranged in rings throughout their body. Each species has a distinct number of rings. Seahorses swim upright