David Shale / Greater silver hatchet fish (Argyropelecus gigas) Mid-Atlantic Ridge, North Atlantic Ocean

Norbert Wu / Slender Hatchetfish (Argyropelecus affinis) deep sea, San Clemente Basin, California

Norbert Wu / Viperfish (Chauliodus sp) chasing Hatchetfish (Sternoptyx sp) deep sea

David Shale / Deep sea Hatchet fish {Sternoptychidae} Atlantic ocean

Solvin Zankl / Loosejaw fish (Malacosteus niger) with a light organ beneath its eye. Deep sea species in Atlantic Ocean off Cape Verde. Captive.

Solvin Zankl / Deep sea hatchetfish (Sternoptyx diaphana) profile. Deep sea species from Atlantic Ocean close to Cape Verde. Captive.

Solvin Zankl / Photophores of Diaphanous hatchetfish (Sternoptyx diaphana), photographed from underneath. Deep sea species from Atlantic Ocean off Cape Verde. Captive.

Solvin Zankl / Black dragonfish (Malacosteus niger) deep sea species with a light organ beneath its eye. Atlantic Ocean off Cape Verde. Captive.

David Shale / Greater silver hatchet fish (Argyropelecus gigas) head profile, Mid-Atlantic Ridge, North Atlantic Ocean

David Shale / Ventral view of Hatchet Fish {Argyropelecus hemigymnus} from 2666 - 0m, Mid-Atlantic Ridge, North Atlantic Ocean

David Shale / Close up of abdomen of Greater silver hatchet fish (Argyropelecus gigas) showing ventral light organs, Mid-Atlantic Ridge, North Atlantic Ocean

David Shale / Greater silver hatchet fish (Argyropelecus gigas) Mid-Atlantic Ridge, North Atlantic Ocean