These fish are closely related to seahorses and are long, thin and typically dull in color, although several species are brightly colored. The largest species may reach up to two feet in length. Their bodies are less rigid than seahorses' and few pipefish have a grasping, prehensile tail. Pipefish are common in bays, tide pools, lagoons and other slopes of coral reefs around the world. Some species may even live in fresh water.
Some pipefish have unique habitats, including one species that lives in a sea cucumber's intestines.
Pipefish life histories are more variable than seahorses. In most species, males carry the developing young in two long abdominal pouches, while in other species, the male glues the developing eggs to the undersides of their tails. Some types of pipefish resemble seahorses more than others.