Urocampus nanus, commonly known as the barbed pipefish, is a species of marine fish belonging to the family Syngnathidae.

[3] For locomotion, the barbed pipefish relies on quick movements from their dorsal and pectoral fins, which gives them a good amount of body control.

[5] Generally, species in the family Syngnathidae are located in the Pacific, Indian, and Atlantic oceans in temperate to tropical waters.

If the fish is attached to a holdfast, it acts as sit-and-wait predators; if it is free in the water, it will actively hunt their prey.

When they are ready to strike, the fish rapidly rotates its head to be able to snap its mouths toward the prey and consume them through suction.

[5][7] The head rotation and muscle activation used by pipefish during this hunting is similar to the movement of chameleon, frog, and salamander tongues.

Males brood eggs for 11–16 days before giving live birth, making the barbed pipefish ovoviviparous.

[2] There are six stages in mating for this species: lateral display, rising up, holding, parallel swim, copulation, and wiggling.

Spawning or copulation occurs when the two stop swimming, put their genitals together, and the female extrudes eggs to be accepted by the male.

[1] If these disturbances continue over a long period of time, it could lead to an overall loss of seagrass habitats in the Northwest Pacific.