[3][4] Its name derives from the Greek λεπτός (leptos, "small"); χεῖλος (cheilos, "lip"); and ἰχθύς (ichthys, "fish").

The maxillae are considered especially long There are teeth on the palate and dentary.

Thirteen branchiostegal rays support the gill membranes behind the lower jaw.

[2] Leptochilichthys species are found in deep sea regions in the eastern Atlantic, western Indian, and eastern and western Pacific Oceans.

They are most commonly found at depths of 1,000 metres (3,300 ft) and below, but are in general not well known.