Doryrhamphus janssi has a long, slender body with an elongated, tubular mouth.

[3] The body of this species is bright orange while the head and anterior portion of the trunk are blue.

The Janss' pipefish is found in the tropical waters of the central Indo-Pacific area, from Indonesia to the Philippines, this latter is the northern and eastern limit of the species distribution.

[3] It is ovoviviparous and like for the seahorse, the male carries the eggs in a brood pouch.

[5] The specific name honours Edwin Janns Jr., a Los Angeles property developer who had a keen interest in marine biology.