; subclass Actinopterygii, order Syngnathiformes)
A large family of mainly marine fish in which the body is encased in a series of bony rings or plates. They have a tube-like snout with a minute mouth at the tip, a single dorsal fin, and no pelvic fins. Such species as Nerophis ophidion (straight-nosed pipefish), 60 cm, and Hippocampus hippocampus (sea-horse), 15 cm, of the eastern Atlantic, both of which are usually found among seaweeds, are known to keep their young temporarily in a brood pouch developed by the male. A few, e.g. Phycodurus eques (leafy sea dragon), 30 cm, of southern Australia, form elaborate leaf-like appendages, making it very hard to see the fish when they are hidden between branches of seaweed. There are about 175 species, distributed world-wide.
Subjects: Zoology and Animal Sciences.