Enneapterygius elegans, the hourglass triplefin (or elegant triplefin in the United Kingdom), is a species of triplefin blenny in the genus Enneapterygius. It was originally described by Wilhelm Peters as a species of Tripterygium, in 1876,[1] but was reassigned to Enneapterygius by W. Holleman in 1986.[2] It is a tropical blenny known from reefs across the western central Indian to the central Pacific Ocean, and swims at a depth range of 0–12 metres. Male hourglass triplefins can reach a maximum length of 4 centimetres. The blenny gets its common name from an hourglass-shaped marking on its body.