See text The Syngnathidae is a family of fish which includes seahorses, pipefishes, and seadragons (Phycodurus and Phyllopteryx).

They are characterised by their elongated snouts, fused jaws, the absence of pelvic fins, and by thick plates of bony armour covering their bodies.

As a result, they are relatively slow compared with other fish but are able to control their movements with great precision, including hovering in place for extended periods.

[7] In species with more developed, enclosed pouches it has been demonstrated that males directly provide their brood with not only nutrients[8] but also immunity to pathogens.

Evolutionary transitions from female to male care are practically nonexistent in teleosts, so brood pouches were likely not ancestral.

Early members of the family developed traits to limit the presence of deleterious mutations, allowing for more rapid evolution.

In species with the most complex brood pouch systems, many traits (behavioral, physiological, morphological, and immunological) must have co‑evolved to allow for male pregnancy, driven by the increase of the fitness of those individuals’ offspring.

[18][19] Recent research, especially whole-genome sequencing,[16] has allowed for greatly improved understanding of the evolutionary history of Syngnathidae, but there is still a need for further development in the field.