The silver spinyfin, Diretmus argenteus, is a spinyfin of the genus Diretmus, found around the world except the Mediterranean, at depths down to 2,000 m. It belongs to the monotypic genus Diretmus. Their length is between 30 and 40 cm.

The silver spinyfin is a widely distributed but rare species with a flattened disc-shaped body with a sharp scute-covered edge on the belly. A large upturned mouth and huge eye dominate the front half of the disc and a small forked tail projects from the other. They are oviparous and the larvae spend time in the plankton.