Argyropelecus hemigymnus, the half-naked hatchetfish, short silver hatchetfish or spurred hatchetfish, is a deep-sea hatchetfish of the genus Argyropelecus found in mesopelagically in all oceans. It is a small species rarely exceeding 38 millimetres standard length.

Sloane's viperfish (Chauliodus sloani) is a dragonfish of the genus Chauliodus, found in all tropical and subtropical oceans, at depths down to 2,500 m. Its length is between 20 and 35 cm.