They typically have slender bodies with a dark to black underbelly containing brilliant green light organs. The side of the fihs is dark grey and they have transparent white fins.Their upper teeth are separate and widely spaced with sharo points while the lower ones are broad and overlapping to create a continuous cutting edge.

They are often caught in trawls on the continental slope in depths of 200-600m deep.

Stomach contents indicate that these sharks feed on squid, small fish (especially lantern fish) and the occasional shrimp. They often contain pieces bitten from squid much larger than themselves and it has been suggested that they hunt in packs, and it is possible that the green glowing underbelly helps the members of the school remain in contact with each other.

It is ovoviviparous (the embryos hatching inside the uterus and being sustained by a yolk sac), giving birth to litters of six to 20 young every two to three years. The gestation period is under one year. The shark's bioluminescence develops before birth; the yolk sac is fluorescent before any photophores have formed, suggesting the mother transfers luminescent materials to her offspring. There are 33 described species of Lucifer or Lantern sharks.

Collins Guide to the Sea fishes of NZ: Ayling & Cox
Coelho, R., T. Blasdale, C. Mancusi, F. Serena, J. Guallart, N. Ungaro, F. Litvinov, P. Crozier and C. Stenberg (2008). "Etmopterus spinax". IUCN Red List of Threatened Species. Version 2010.1. International Union for Conservation of Nature. Retrieved February 7, 2014.