Aulorhynchus flavidus, the tube-snout, is a species of fish related to the sticklebacks. It is the only species in the genus Aulorhynchus which is the only genus currently recognized in the family Aulorhynchidae. This species grows to 18 cm (7.1 in) in total length. It physically resembles the sticklebacks, but has a thinner, longer body, with 24 to 27 small spines in front of the dorsal fin. It also possess a slender snout, hence the common name. Like the sticklebacks, it feeds on small invertebrates and fish larvae. This species finds use as a denizen in public aquariums.