Solenostomus is the only genus in the family Solenostomidae, and includes six currently recognized species.
[4] The animals, none of which are longer than 17 centimetres (6.7 in), float near motionlessly, with the mouth facing downwards, around a background that makes them nearly impossible to see.
They live in open waters except during breeding, when they find a coral reef or muddy bottom, changing color and shape to minimize visibility.
Unlike true pipefish, female ghostpipefishes use their enlarged pelvic fins to brood their eggs until they hatch.
[4] Two fossil ghost pipefish genera, Calamostoma and Solenorhynchus, are known from the Eocene of Italy.