Best Sternoptychidae

Argyropelecus olfersi is a mesopelagic hatchetfish with a laterally compressed body and ventral photophores that produce bioluminescence to match downwelling light from above.

Sternoptyx diaphana, the deep hatchetfish, is a bathypelagic member of family Sternoptychidae found in all major oceans, typically at depths exceeding 1,000 meters.

Argyropelecus affinis, the Pacific hatchetfish, ranges across the Pacific and Indian Oceans and undertakes nightly vertical migrations from deep water to shallower feeding zones.

Argyropelecus hemigymnus is named for the absence of scales on the posterior half of its body and ranges across the Atlantic, Pacific, and Indian Oceans.

Maurolicus species are small mesopelagic fishes named for their rows of pearlescent ventral photophores, which serve as counterillumination camouflage against downwelling sunlight.

The southern hatchetfish is a mesopelagic member of family Sternoptychidae found in Southern Ocean and subantarctic waters, equipped with ventral photophores for bioluminescent counterillumination.