Fish
Lanternfish
Myctophidae · also called lanternfishes
Lanternfish are small enough to overlook entirely, yet by total weight they may outnumber every other fish family in the ocean combined. Every night, in the largest synchronised animal migration on Earth, unimaginable numbers of them rise from the deep to feed near the surface, then sink back down again by dawn — a movement most people will never even know is happening.
Overview
Lanternfish, family Myctophidae, are small deep-sea fish found throughout the world’s oceans, feeding mainly on copepods and krill. Rows of light-producing photophores along the body, arranged in species-specific patterns, give the family its name.
Glowing to vanish, not to shine
Many species use their belly photophores for counter-illumination, a glow matched to filtered surface light that erases their silhouette from predators looking up from below. As a foundational food source for fish, squid, seabirds, and whales, lanternfish quietly underpin an enormous share of ocean food webs.
Status
Least Concern — likely the most abundant fish family in the ocean by biomass, with largely untapped commercial exploitation so far, though any future large-scale harvest would need careful management given how much else depends on them.
Lanternfish: common questions
Why are lanternfish considered possibly the most abundant fish family in the world?
Scientific surveys using sonar and trawl sampling across the world's oceans have consistently suggested that lanternfish, taken together across all species in the family, may account for a very large share, potentially the majority, of the total biomass of all fish combined, a remarkable finding given that most individual lanternfish species are quite small. Their extremely wide distribution across virtually every ocean basin and depth zone, combined with high population densities in many regions, together support this extraordinary total abundance estimate.
What is counter-illumination and why do lanternfish use it?
Counter-illumination is a camouflage strategy in which an animal produces a faint glow on its underside that closely matches the dim light filtering down from the sunlit surface above, effectively cancelling out the fish's silhouette as seen by a predator looking upward from deeper, darker water. Many lanternfish use light-producing organs called photophores arranged along their belly for exactly this purpose, making counter-illumination one of the most important defensive uses of their characteristic bioluminescence.
How important are lanternfish to the rest of the ocean food web?
Given their enormous total numbers, lanternfish serve as a foundational food source for a very wide range of larger ocean predators, including numerous commercially valuable fish species, squid, seabirds, and some marine mammals such as seals and certain whales, making them one of the most ecologically significant fish families despite receiving relatively little public attention. Their nightly vertical migration toward the surface also plays a meaningful role in transporting energy and nutrients between different depth layers of the ocean each day.
Could lanternfish become a major human food source in the future?
Their enormous estimated biomass has led some researchers and fishing industry analysts to propose lanternfish as a potential large-scale future fishery, but significant practical challenges, including the technical difficulty and cost of efficiently harvesting a small, deep-dwelling fish, along with serious ecological concerns about disrupting a species so central to ocean food webs, have so far limited any major commercial exploitation. Any future large-scale harvesting would likely require careful, precautionary management given how heavily other important ocean species depend on lanternfish as a primary food source.