High Quality Content by WIKIPEDIA articles! The marine hatchetfishes or deep-sea hatchetfishes as well as the related bottlelights, pearlsides and constellationfishes are small deep-sea bathypelagic ray-finned fish of the stomiiform family Sternoptychidae. They should not be confused with the freshwater hatchetfishes, which are not particularly closely related Teleostei in the characiform family Gasteropelecidae. The Sternoptychidae have 10 genera and about 70 species altogether.