They are pelagic fishes, found in the middle and depths of most oceans.

They are distinguished by the presence of a series stripes on the head that form part of the sensory system, but otherwise the two genera of the family are quite different in appearance.

Derichthys has a narrow neck and large eyes, while Nessorhamphus' has a long, flattened, snout.

[2] They grow to about 60 cm (24 in) in length.

The three species in two genera are:[3] In some classifications (for example, Systema Naturae 2000), this family is split in two, with Derichthyidae containing only the genus Derichthys, and Nessorhamphus being assigned its own family, Nessorhamphidae.