This Fish Sustains 70% of the World's Oceans — But Why Have We Never Seen It?

This Fish Sustains 70% of the World's Oceans — But Why Have We Never Seen It?. In the dark depths untouched by sunlight, there are fish whose biomass exceeds all commercial fish in the world — yet almost no one has seen them directly. It is not a fictional creature, nor a newly discovered species this year, nor a genetically engineered one. It has existed since the time of the dinosaurs. What is the secret behind its quiet yet dominant presence?. What are Myctophiformes — and why does their name sound like an ancient Greek incantation? Myctophiformes is not a nickname for deep-sea infiltrators or a naval code. It is the scientific name for a group of bony fish — specifically, ray-finned fish Actinopterygii that live mainly in the mesopelagic zone 200–1,000 meters below the surface . The name comes from three roots: myktér μυκτήρ in Ancient Greek meaning 'nose' or 'snout', óphis ὄφῖς meaning 'snake', and forma in Latin meaning 'shape'. Literally, Myctophiformes means 'snake-nosed'. And yes — if you look at their micrographs, their snouts are indeed long, pointed, and somewhat heavy, while their bodies are slender like a frozen snake in cold water. However, do not be deceived by the seemingly ominous name: most species are only 2–10 cm long, and they are not dangerous to humans — in fact, they are one of the main drivers of the marine ecosystem. Why is this tiny fish said to 'rule 70% of the world's oceans'? This number is not hyperbolic. According to a recent study by Deep Sea Research Part I 2022 , the global biomass of Myctophidae — the main family within the order Myctophiformes — is estimated between 500 million to 1 billion metric tons . For comparison: the total amount of all commercial fish caught by humans in a year — including tuna, cod, and salmon — is about 90 million tons. This means that lanternfish the common name for Myctophidae have a biomass more than five times greater than all the fish we eat in a year. They are found in all oceans — from the Arctic to the Antarctic, from the central Pacific to the Indian Ocean — and are most dense in the 'midnight zone' 200–1,000 m , where sunlight is almost nonexistent. Their presence is not just numerous; it is structural : they serve as a crucial link between surface phytoplankton and larger predators such as swordfish, whales, and seabirds. How can such a small fish 'light up' the deep ocean — without electricity? Lanternfish lightfish are not a random name. More than 95% of Myctophidae species have bioluminescent organs — specialized glands that produce light through a chemical reaction between luciferin and the enzyme luciferase, with oxygen as a catalyst. What is astonishing: this light is physiologically controlled . It is not constantly glowing, but activated and turned off through nerves and hormones — like remote-controlled LED lights. Its functions are varied: to deceive predators counter-illumination , attract small prey such as copepods, and even for species recognition during reproduction. Some species have unique light patterns on their sides — like 'light fingerprints' — which distinguish them from each other. A study using ROVs Remotely Operated Vehicles in the Gulf of Mexico showed that in just one hour, more than 3,000 lanternfish individuals can be seen blinking in coherent formations — a 'light dance' that scientists have not fully understood yet. Are Myctophiformes really 'two families' — or one family divided by evolutionary fate? Taxonomically, Myctophiformes consists of two families: Myctophidae lanternfish — 252 species, 30 genera and Neoscopelidae blackchins — only 6 species in 3 genera . Although similar in habitat and general morphology, genetic differences suggest that Neoscopelidae may be an early branch that split off earlier — about 85 million years ago, at the end of the Cretaceous. They are less adapted to daily vertical migration Diel Vertical Migration , an iconic trait of Myctophidae, where millions of fish rise to the surface at night to feed on zooplankton, then descend back before dawn. Blackchins tend to stay deeper and are less active. This makes Myctophidae not just a family of fish — but an ecological phenomenon that drives the daily flow of carbon in the ocean. Why do we rarely hear about them — even though they are the 'hidden engine' of the ocean? Because they do not appear in fish markets. Because they disintegrate quickly in trawl nets. Because their skin and muscles are soft, watery, and cannot withstand pressure when brought to the surface — many of them burst before reaching the ship. Because they do not swim near the surface, do not appear in BBC documentaries like Blue Planet , and are not the subject of advertisements. However, in laboratories, they become important models for understanding adaptations to extreme pressure, low oxygen metabolism, and the evolution of nervous systems in eternal darkness. A European-Japanese collaborative project 2023 even used mitochondrial DNA from lanternfish to track ocean temperature changes since the Pleistocene — because their populations are so sensitive that even a 0.5°C change can shift their geographic distribution within less than a decade. They are not forgotten fish. They are fish that remind : the ocean is not just what we see — but what flickers in the darkness, without asking for attention. --- Reference: Myctophiformes — Wikipedia https://en.wikipedia.org/wiki/Myctophiformes