Appearance
They have extremely compressed, razor-like bodies which have a sharp ventral edge and a dorsal surface which is nearly straight in profile ending in a long snout which has a tiny mouth with pincer-like jaws which lack teeth. The spiny part of the dorsal fin is located close to the tail and is made of one long, sharp spine at the anterior end with two shorter spines behind that. The soft, posterior part of the dorsal fin and the caudal fin are situated on the ventral surface and lie below the posterior-most part of the body, which is pointed. The pelvic fins are small and are located around the middle of its body while the pectoral fins are larger. The body is almost completely covered in thin, translucent bony plates which are created by expansion of its vertebrae. The species within this family do not have a lateral line.
